Cows milk protein intolerance and chronic fatigue syndrome

"Cow's milk protein intolerance is a common problem in young people with chronic fatigue syndrome, and is a treatable contributor to their symptoms."

So said the paper by Peter Rowe and colleagues [1] who looked prospectively for signs of cow's milk protein intolerance (CMPI) in "55 adolescents and young adults with chronic fatigue syndrome" over the course of 2 years. Defining CMPI using 4 factors: "(1) no evidence of immediate or anaphylactic reactions to milk, (2) at least 2 of the following 3 chronic symptoms: gastroesophageal reflux, early satiety, and epigastric/abdominal pain, (3) improvement in upper gastrointestinal symptoms on a milk protein elimination diet, and (4) at least 2 recurrences of upper gastrointestinal symptoms > 2 hours following open re-exposure to milk protein" researchers set about on this fairly unusual study course to ascertain some preliminary prevalence data and to see what impact such food issues might have on self-reported quality of life.

Nearly a third of their quite small participant group (17/55) hit their thresholds for CMPI and we are told that in comparison to non-CMPI participants, those with milk issues "had significantly worse health-related quality of life at baseline but not at 6 months (after institution of the milk-free diet)." As per that opening quote, prevalence of CMPI might be common in cases of CFS and might play some not insignificant role on quality of life.

Wearing my 'diet and behaviour' hat (see here for example) the Rowe results make for interesting reading. The fact that some of the authors have quite a lot of research standing when it comes to chronic fatigue syndrome (CFS) adds to my interest in these results; specifically with another of their papers in mind on orthostatic intolerance and gastrointestinal (GI) symptoms [2] for example (orthostatic intolerance = development of symptoms when standing upright, and is thought to be linked to quite a few cases of CFS).

Quality of life (health-related) when applied to CFS is something else that has already been covered on this blog (see here) and the observation that its presentation can be about as bad as it gets for some people in comparison to various other diagnostic labels. Anything therefore that can improve [elements of] such an important measure has to be taken seriously, particularly when it is something as 'treatable' as potentially eliminating milk from ones diet (I say this with no medical or clinical advice given or intended).

But just before anyone decides to embark of a milk-free diet solely on the basis of Rowe results, a bit of a research 'to-do' list to think about in this area: (a) The sample size was quite small and we need to know more with larger sample sizes and perhaps more strenuous research methodologies. (b) The measures used to assess CMPI didn't appear to include anything 'biological'. I know this is still a bit of a grey area in terms of 'intolerance vs' allergy' but I'd like to think that more could be attempted during future study including that related to those bowel symptoms [3] given previous discussions in this area (see here). (c) Given that this was a study of CFS I think most people would like to know whether CFS symptoms were impacted by a milk-free diet as well as quality of life measures. Again, measuring CFS is not the easiest of tasks given the number of definitions (see here) but it's not impossible. (d) Acknowledging that not all milk is the same (see here and see here) and that protein is but one element of milk, I have to wonder whether it might be worthwhile doing some further study on this too. Given also that institution of a milk-free diet is not without potential complications, the question is once again: is there more science to be done?

But that doesn't mean that the Rowe results are not interesting...

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[1] Rowe PC. et al. Cow's Milk Protein Intolerance in Adolescents and Young Adults with Chronic Fatigue Syndrome. Acta Paediatr. 2016 May 13.

[2] Sullivan SD. et al. Gastrointestinal symptoms associated with orthostatic intolerance. J Pediatr Gastroenterol Nutr. 2005 Apr;40(4):425-8.

[3] Frissora CL. & Koch KL. Symptom overlap and comorbidity of irritable bowel syndrome with other conditions. Curr Gastroenterol Rep. 2005 Aug;7(4):264-71.

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Rowe, P., Marden, C., Jasion, S., Cranston, E., Flaherty, M., & Kelly, K. (2016). Cow's Milk Protein Intolerance in Adolescents and Young Adults with Chronic Fatigue Syndrome Acta Paediatrica DOI: 10.1111/apa.13476

Organic pollutants and behavioural severity in autism?

"This study supports the hypothesis that environmental exposure to organic pollutants may play a significant role in the behavioral presentation of autism."

Accepting that correlation is not the same as causation, the results published by Andrew Boggess and colleagues [1] (open-access here) make for some blogging fodder today and the idea that serum levels of various compounds headed under the description of organic pollutants (persistent or otherwise) might show some important connections to at least some autism.

To get a few things straight first, this and other related research does not say that every diagnosis of autism is somehow the product of a 'toxic' exposure. Nor does it belittle the substantial contribution that genetics (whether structural or non-structural issues) confer when it comes to diagnosis. To my mind, it adds another level of complexity to the [various] hows and whys relating to how autism might come about [2]. That, and offering some important biologically-led guidance on what might be done to decrease any body load of such pollutants as and when they are detected and there's quite a bit we can learn from such studies.

Anyhow, Boggess et al started from the position of wanting to "evaluate the relationship between organic pollutants and behavioral severity in children with ASD [autism spectrum disorder] and matched controls." Thirty children diagnosed with autism were matched (age and sex) with 30 children without autism. Quite a panel of diagnostic and screening instruments were included as part of the study protocol, including ADOS (Autism Diagnostic Observation Schedule) and interestingly, the ATEC (see here). Each participant provided a blood sample, and the serum portion of the sample was subject to analysis by GC-MS (Gas Chromatography-Mass Spectrometry) for various compounds. Compounds included: "Three volatile organic compounds (VOC), benzene, toluene, and o-xylene; one alkane, hexane; five polychlorinated biphenyls (PCB), IUPAC congeners 28, 52, 101, 138, and 153; two polybrominated diphenylethers (PBDE), IUPAC congeners 47 and 99; two organochlorine pesticides, metolachlor and acetochlor; one dinitroanaline pesticide, pendimethalin; one organophosphate pesticide, chlorpyrifos; one phthalate, bis (2-ethylhexyl) phthalate (DEHP); and the chlorocarbon perchloroethylene."

Results: well, looking directly at the metabolites under inspection and comparing the group results (autism group vs control group) in terms of individual quantified levels, there seemed very little see. The only compound that was statistically significant in terms of amounts between the groups was something called metolachlor, a herbicide, which was actually found in higher mean concentrations in the control group than the autism group. When also researchers compared "the pooled mean of all compounds from the ASD cohort to the pooled mean for all compounds in the control cohort" they similarly noted no significant difference. At this point you're probably thinking that this isn't particularly interesting data. Well, just hold it there...

Researchers further examined whether there was something to see when comparing the mean xenobiotic body-burden (MXB) and those ADOS scores. Xenobiotic by the way, is another way of saying (foreign) compounds that were being assayed for, and combined with ADOS scores was a way of looking at whether behavioural severity might show some link to the concentrations of those compounds being reported on. In this respect: "Pooled serum-concentration correlated significantly with increasing behavioral severity on the ADOS in the ASD cohort... but not controls." The authors go on to say that such findings and others are "a fundamental expectation from the hypothesis of genetic predisposition for susceptibility to environmental triggers."

Some other points are raised in the Boggess paper not least those connected to the various biological mechanisms designed to metabolise such compounds and where they may fit with regards to some autism. Personally, I think this is where the money is eventually going to be; with further work required on processes linked to glutathione (see here) and more specific genetic-biological issues (e.g. PON1 [3]) potentially showing how genetic fragility and non-genetic factors might combine specifically when it comes to getting rid of various pollutants from the body.

There are methodological issues with the Boggess paper that do need to be mentioned not least the small participant group and the reliance on one blood sample showing a snapshot of current biology (combined with a snapshot of current behaviour). This last point in particular tells us little about any historical issues and whether there are important time-frames where environmental exposures might exert a more significant effect and the impact of any genetic issues. But, in the context of other research talking about environmental factors potentially being linked to autism (see here for example) it would be unwise to rule anything out just yet...

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[1] Boggess A. et al. Mean serum-level of common organic pollutants is predictive of behavioral severity in children with autism spectrum disorders. Sci Rep. 2016 May 13;6:26185.

[2] Vijayakumar NT. & Judy MV. Autism spectrum disorders: Integration of the genome, transcriptome and the environment. Journal of the Neurological Sciences. 2016; 364: 167-176.

[3] Gaita L. et al. Decreased serum arylesterase activity in autism spectrum disorders. Psychiatry Res. 2010 Dec 30;180(2-3):105-13.

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Boggess A, Faber S, Kern J, & Kingston HM (2016). Mean serum-level of common organic pollutants is predictive of behavioral severity in children with autism spectrum disorders. Scientific reports, 6 PMID: 27174041

Urban neighbourhood, food and risk of psychosis?

It's another research mash-up today as I bring to your attention two papers talking about potential correlates associated with psychosis and/or psychotic symptoms.

First up are the findings reported by Joanne Newbury and colleagues [1] (open-access here) who observed that urban residency and certain factors associated with urban residency might link into a higher risk of childhood psychotic symptoms. A second paper by Tomasz Pawełczyk and colleagues [2] provides some further food for thought and the suggestion that "dietary patterns of PUFA [polyunsaturated fatty acids] consumption may play a role in the conversion to psychosis of HR [ultra high-risk] individuals."

Newbury et al report findings from the Environmental Risk (E-Risk) Longitudinal Twin Study and specifically the idea of "whether specific features of urban neighborhoods increase children's risk for psychotic symptoms." Aside from finding a potential association between urban residency at aged 5 and aged 12 and psychotic symptoms at aged 12, researchers also suggested that: "Low social cohesion, together with crime victimization in the neighborhood explained nearly a quarter of the association between urbanicity and childhood psychotic symptoms after considering family-level confounders."

Pawełczyk et al continued a research theme suggesting that what we do or do not eat might have implications for some with regards to transition to psychosis (see here). Focusing specifically on a group of HR individuals, they looked at the diet of those who did and did not transition into psychosis. They reported: "C-HR [converted into psychosis] individuals reported significantly higher consumption of n-6 fatty acids (linoleic acid, LA and arachidonic acid, AA) in comparison with individuals who did not develop psychosis (NC-HR)."

Although not seemingly covering the same factors when it comes to psychosis/psychotic symptoms, one of the things that I thought might also unite both these findings is food. Yes, Pawełczyk et al already talk about food (albeit based on the warts and all use of "a validated Food-Frequency Questionnaire") but the Newbury paper might also include a food element insofar as what types of food might be more readily available and eaten in urban vs. not-so-urban environments.

Bearing in mind that sweeping generalisations about food availability and importantly, what types of food are available depending on where one lives, are not required, I would like to suggest that spatial patterning of say, supermarkets vs. fast food outlets might be something that could potentially unite results. The paper by Lamichhane and colleagues [3] for example found that: "the availability of supermarkets and fast food outlets differed significantly by neighborhood characteristics; neighborhoods with supermarkets and with fast food outlets were significantly higher in socio-economic status." Research looking at the causes and/or drivers of obesity have tended to predominate in the area of how neighbourhood might influence eating patterns [4] but similar modelling could be done with more psychiatric outcomes in mind. Indeed to quote Newbury et al: "Neighborhood-level physical exposures such as noise, light, and air pollution, as well as exposure to viral infections warrant research in relation to early psychotic symptoms." Who says that food should not also be included?

I don't want to gloss over just how complicated the factors might be bringing someone to clinically relevant psychotic symptoms nor to say that food is somehow the 'missing' element for all cases. But it's not outside of the realms of possibility that in these days of nutritional psychiatry, food might exert an important effect for some people and food availability (certain food availability) could be one factor contributing to the idea that where you live might affect your risk of psychosis...

And if that wasn't enough speculating, how about sweeping generalisations about maternal smoking habits and prenatal nicotine exposure as a risk factor for psychosis+ [5] as something else potentially linked to urban living?

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[1] Newbury J. et al. Why are Children in Urban Neighborhoods at Increased Risk for Psychotic Symptoms? Findings From a UK Longitudinal Cohort Study. Schizophr Bull. 2016 May 6. pii: sbw052.

[2] Pawełczyk T. et al. The association between polyunsaturated fatty acid consumption and the transition to psychosis in ultra-high risk individuals. Prostaglandins Leukot Essent Fatty Acids. 2016 May;108:30-7.

[3] Lamichhane AP. et al. Spatial patterning of supermarkets and fast food outlets with respect to neighborhood characteristics. Health & place. 2013;23:10.1016/j.healthplace.2013.07.002.

[4] Macdonald L. et al. Neighbourhood fast food environment and area deprivation—substitution or concentration? Appetite. 2007; 49: 251-254.

[5] Niemelä S. et al. Prenatal Nicotine Exposure and Risk of Schizophrenia Among Offspring in a National Birth Cohort. American Journal of Psychiatry. 2016. May 24.

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Pawełczyk, T., Trafalska, E., Kotlicka-Antczak, M., & Pawełczyk, A. (2016). The association between polyunsaturated fatty acid consumption and the transition to psychosis in ultra-high risk individuals Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA), 108, 30-37 DOI: 10.1016/j.plefa.2016.03.010




Newbury J, Arseneault L, Caspi A, Moffitt TE, Odgers CL, & Fisher HL (2016). Why are Children in Urban Neighborhoods at Increased Risk for Psychotic Symptoms? Findings From a UK Longitudinal Cohort Study. Schizophrenia bulletin PMID: 27153864

Wandering and autism continued... yet again

I know that I'm probably starting to sound like a broken record on the topic of wandering (elopement) and autism on this blog (see here and see here and see here) but I am yet again going to briefly talk about peer-reviewed research in this area simply because it's just too damned important not to.

This time around the results from Catherine Rice and colleagues [1] are the source of my musings and the conclusion that: "wandering among children with ASD [autism spectrum disorder], regardless of intellectual disability status, is relatively common." Based on the analysis of data from The Survey of Pathways to Diagnosis and Services (SPDS) initiative, where specific questions about 'wandering and wandering prevention' are asked (see page 29) researchers reported that: "For children with special healthcare needs diagnosed with either ASD, intellectual disability, or both, wandering or becoming lost during the previous year was reported for more than 1 in 4 children." A diagnosis of ASD seemed to be a key factor in the frequency of wandering, where those with additional learning disability were the most likely to wander (37% of the sample) and figures for those without intellectual disability came in at about 32%.

As per previous occasions when I've blogged about this topic, the differences (kingdoms) that might divide various groups/people when it comes to autism tend to take second place when it comes to tackling this issue and preventing (yes, preventing) wandering from turning into something rather more ominous. After all, there are a range of measures that can be employed to reduce the frequency of wandering/elopement and, if and when it does happen, reduce the probability of 'adverse outcomes' for the wanderer. First and foremost I would say, is for more people to take note of actual accounts about wandering as per those discussed by Solomon and Lawlor [2] for example. One can learn a lot about the circumstances around why wandering occurs and the different types of wandering (including the issue of bolting) from listening to parent and caregiver accounts. They are the experts on their own children and no doubt some of those accounts might generalise to more than just one child.

Next up are the various instruments that could be used to help find wanderers in a timely fashion. I'm thinking specifically about technology such as GPS trackers and the need for science to provide some further insight into the effectiveness of such items and what needs to be done to improve their effectiveness. I appreciate that 'tracking people' might have implications for things like civil liberties but just remember that the mobile (cell) phone you're carrying might not also be bad at telling others where you are. Improving autism awareness among first responders such as police and related agencies may also help them in their efforts if and when wandering becomes an issue.

Finally and bearing in mind that 'if you've met one person with autism, you've met one autistic person' (or words to that effect) is the importance of teaching things like road and water safety to those on the autism spectrum. I appreciate that the concept of 'danger' might not be something easily taught to some children and communication issues can be barriers to effective teaching. But, one should not assume that it is impossible to do [2], alongside the strategies for making lessons like swimming classes for example 'fun' as well as potentially lifesaving. And yes, swimming lessons can be particularly fun for many children on the autism spectrum [3].

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[1] Rice CE. et al. Reported Wandering Behavior among Children with Autism Spectrum Disorder and/or Intellectual Disability. J Pediatr. 2016 May 2. pii: S0022-3476(16)00428-5.

[2] Call NA. et al. Clinical outcomes of behavioral treatments for elopement in individuals with autism spectrum disorder and other developmental disabilities. Autism. 2016 May 12. pii: 1362361316644732.

[3] Eversole M. et al. Leisure Activity Enjoyment of Children with Autism Spectrum Disorders. J Autism Dev Disord. 2016 Jan;46(1):10-20.

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Rice, C., Zablotsky, B., Avila, R., Colpe, L., Schieve, L., Pringle, B., & Blumberg, S. (2016). Reported Wandering Behavior among Children with Autism Spectrum Disorder and/or Intellectual Disability The Journal of Pediatrics DOI: 10.1016/j.jpeds.2016.03.047

CRISPR-Cas9 and autism research

If you feel brave enough, today I will direct your reading attention to the paper by Michael Williams and colleagues [1] detailing the application of a particularly important genome editing technique called CRISPR-Cas9 [2] to autism-related science.

Titled: "A Retroviral CRISPR-Cas9 System for Cellular Autism-Associated Phenotype Discovery in Developing Neurons" the Williams paper probably won't win any awards for plain English but don't be fooled about just how important this paper might be in the grand era of 'we can edit genomes' and how this might translate into modelling particular types of autism or genetic issues linked to autism in mice or other animals for example.

I really wish that I could say I was an expert on CRISPR-Cas9 and understood every detail included in the Williams paper but alas, I'm not and I didn't. Bearing in mind my non-expertise ('a cobbler should stick to his last') I did want to include it on this blog given the excitement in this area. Take my observations however, with a large pinch of salt...

So a definition of CRISPR [clustered regularly interspaced short palindromic repeats] -Cas9 - well, I don't want to reinvent the wheel so I'll use that offered in reference [2] with full credit given to the writer (Steph Yin): "Here’s how CRISPR/Cas works in bacteria: When bacteria encounter an invading source of DNA, such as from a virus, they can copy and incorporate segments of the foreign DNA into their genome as “spacers” between the short DNA repeats in CRISPR. These spacers enhance the bacteria’s immune response by providing a template for RNA molecules to quickly identify and target the same DNA sequence in the event of future viral infections. If the RNA molecules recognize an incoming sequence of foreign DNA, they guide the CRISPR complex to that sequence. There, the bacteria’s Cas proteins, which are specialized for cutting DNA, splice and disable the invading gene." The application of this process outside of just bacteria was subsequently recognised and a 'gene editing tool' was eventually born whereby a CRISPR-Cas9 system could replace any gene sequence.

Clear as mud right?

Well, Williams et al add to a small but emerging peer-reviewed research base at the time of writing suggesting that CRISPR-Cas9 might provide some important insights into at least 'some' autism. Their particular idea was to "mimic nonsense PTEN mutations from autism patients in developing mouse neurons" on the back of some previous research suggesting that various genetic issues with PTEN might be present in some autism [2]. Nonsense mutation by the way, normally ends in 'nonfunctional proteins' based on the knowledge that [some] genes provide the template to make proteins.

To achieve such mutations in PTEN authors used "retroviral implementation of the CRISPR-Cas9 system" where engineered retroviruses were purposed to deliver something mimicking a genetic mutation previously noted in cases of autism that were then injected into "the hippocampus of postnatal day 7 (P7) mice." Researchers then monitored the retrovirus infected cells to see what they looked like in terms of carrying the mutation and hence showing loss of PTEN function or not. They noted that there was a degree of 'hit-and-miss' based on their approach but were "able to clearly discern the established hypertrophic phenotype due to loss of Pten function across the cell population on average."

Not content with such molecular engineering, authors also turned their attention to designing viruses "to target a gene that has recently been associated with autism, KATNAL2." KATNAL2 has been described by other authors as a 'genuine' autism risk factor [3] (er, right...) and on that basis researchers designed a retrovirus carrying a mutation designed to disrupt expression of the gene. After some preliminary work to test out how successful their retrovirus delivered mutation was in the test tube, they injected it and/or a control retrovirus into the brain of another set of mice. They found some interesting changes in the experimental retrovirus-infected brains pertinent to "decreased dendritic arborization of developing neurons." In layman's terms this equates as evidence of "disruption of normal neuronal development" that "may lead to synaptic circuit dysfunction underlying the autism phenotype."

As per my earlier 'pinch of salt' sentiments I am not offering any authoritative opinion about the Williams paper and the techniques included. My interpretation is just that; interested readers are advised to do a little more reading around this subject before quoting my text as 'truth'. What I do hope that I've got across is the message that CRISPR-Cas9 and the delivery of engineered genetic mutations via something like a retrovirus is already here and will no doubt be impacting on autism research in times to come. In an era where 'the autism gene' has been replaced by a more general model of many different genes potentially producing many different autisms (see here), one can perhaps see how focusing in on specific genes linked to 'some' autism might be ripe for this kind of analysis (see here). I say all that recognising that whilst many would love to be able to say that autism is solely a genetic condition, the role of non-genetic factors variably affecting risk is not to be forgotten (see here).

We will see what else emerges in the peer-reviewed domain in this brave new world...

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[1] Williams MR. et al. A Retroviral CRISPR-Cas9 System for Cellular Autism-Associated Phenotype Discovery in Developing Neurons. Sci Rep. 2016 May 10;6:25611.

[2] Yin S. What Is CRISPR/Cas9 and Why Is It Suddenly Everywhere? Motherboard. 2015. April 30.

[3] Neale BM. et al. Patterns and rates of exonic de novo mutations in autism spectrum disorders. Nature. 2012 Apr 4;485(7397):242-5.

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Williams MR, Fricano-Kugler CJ, Getz SA, Skelton PD, Lee J, Rizzuto CP, Geller JS, Li M, & Luikart BW (2016). A Retroviral CRISPR-Cas9 System for Cellular Autism-Associated Phenotype Discovery in Developing Neurons. Scientific reports, 6 PMID: 27161796

The persistence of self-injury in relation to autism

Some behaviours associated with a diagnosis of autism don't make for great dinner table discussion. Self-injurious behaviours (SIBs), as exemplified by head banging, hair pulling and eye gouging must rank as some of the more distressing facets of [some] autism insofar as their potential effect on the person and also the people around them.

These and other types of behaviour commonly headed under the category of so-called 'challenging behaviours' have tended not to be too evident when it comes to the public depiction of autism it has to be said. I can appreciate why, but what this can mean is that such issues tend to get 'brushed under the carpet'. In recent times however, there does seem to be a greater willingness for research to delve into such behaviours [1].

The paper by Caroline Richards and colleagues [2] (open-access) looking at the persistence of such behaviour(s) and the potential correlates associated with their persistence is a welcome piece of research added to the research interest. Highlighting how for a small research sample of 67 children/young adults with autism over three-quarters reported SIB persisting over a 3-year period, the data provide some interesting insights into the nature of this issue and, potentially how it should be screened for and managed.

Based here in Blighty, researchers initially managed to recruit 190 participants, the data for some of whom were previously published [3]. As perhaps one might expect, the follow-up after on average 36.4 months had elapsed was not so well-populated. No mind, various findings are reported including that "the presence, topography and severity of self-injury were persistent and stable over three years" and that "individuals with self-injury were significantly more likely to be non-verbal than those who did not engage in self-injury." Further: "individuals with self-injury were significantly more likely to be less able and non-verbal and to show higher levels of stereotyped behaviour, compulsive behaviour, insistence on sameness, overactivity, impulsivity, repetitive behaviour and impairments in social interaction."

There is quite a bit more to do on this topic including facing up to issues around the small (eventual) participant size and the reliance on 'a questionnaire pack' as the chosen method of assessment. The authors also talk quite a bit about how some of the behaviours observed in connection with self-injury - impaired behavioural inhibition - might overlap with other diagnoses such as attention-deficit hyperactivity disorder (ADHD) but as far as I can see, they did not directly screen for ADHD outside of the use of something called The Activity Questionnaire (TAQ). I might also have liked to have seen a little more information about how parents/professionals had 'tackled' SIB in this cohort and what effect that might have had on results. Investigations remain.

Having said all that, the insights provided by the Richards article are important and provide plenty of food for thought when it comes to SIB and autism. Without trying to generalise SIB to all autism nor to come across as portraying too negative an image of what autism can mean to someone, recognition and management (dare I say treatment) of such behaviours when present should really be a priority [4].

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[1] Maddox BB. et al. Untended wounds: Non-suicidal self-injury in adults with autism spectrum disorder. Autism. 2016 May 12. pii: 1362361316644731.

[2] Richards C. et al. Persistence of self-injurious behaviour in autism spectrum disorder over 3 years: a prospective cohort study of risk markers. Journal of Neurodevelopmental Disorders 2016; 8: 21.

[3] Richards C. et al. Self-injurious behaviour in individuals with autism spectrum disorder and intellectual disability. J Intellect Disabil Res. 2012 May;56(5):476-89.

[4] Lee Y-H. et al. Cataract secondary to self-inflicted blunt trauma in children with autism spectrum disorder. Journal of American Association for Pediatric Ophthalmology and Strabismus. 2016. May 17.

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Richards, C., Moss, J., Nelson, L., & Oliver, C. (2016). Persistence of self-injurious behaviour in autism spectrum disorder over 3 years: a prospective cohort study of risk markers Journal of Neurodevelopmental Disorders, 8 (1) DOI: 10.1186/s11689-016-9153-x

Around 1 in 5 with autism will experience seizure or seizure disorder

The paper by Jennifer Jaskiewicz and colleagues [1] recently offered a further important insight into the relationship between autism and seizure or seizure disorder (i.e. epilepsy).

Based on the examination of records of nearly 50,000 children and young adults diagnosed with an autism spectrum disorder (ASD) compared with approximately quarter of a million 'not-autism' participants, authors reported some interesting trends. Concluding that some 19% of participants with autism experienced "some kind of seizure or seizure disorder", the study in particular reaffirms something of an important relationship between [some] autism and [some] epilepsy or seizure disorder.

Drawing on data derived from the US Military Health System database between 2000-2013, the records of children and young adults aged 0-18 years were the focus of analysis, where those with autism were age and sex-matched with asymptomatic (not autism) controls. Alongside the heightened risk of a general description of 'seizure or seizure disorder' in the autism group, authors also reported that specific issues such as status epilepticus and absence seizures were over-represented in the autism group. Febrile seizures - seizures that accompany fever - were also over-represented in the autism group although to a slightly lower extent than other seizure types. The authors conclude that: "Rates of epilepsy in children with autism are vastly increased in a wide variety of seizure types, known to have different etiologies, genetic and otherwise." Compare also the estimate of epilepsy or seizure disorder shown here with other population figures [2] and you get a flavour for how advanced the risk might be...

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[1] Jaskiewicz J. et al. Quantification of Risks of Seizure in Autism. Neurology. 2016; 86: suppl. S32.003.

[2] Russ SA. et al. A national profile of childhood epilepsy and seizure disorder. Pediatrics. 2012 Feb;129(2):256-64

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Jennifer Jaskiewicz, Apryl Susi, Elizabeth Hisle-Gorman, David Dennison, Gregory Gorman, Cade Nylund, & Christine Erdie-Lalena (2016). Quantification of Risks of Seizure in Autism Neurology

Sex-specific immune response to Candida albicans in schizophrenia and beyond

I have quite a bit of time for the various members of the Stanley Division of Developmental Neurovirology at Johns Hopkins on this blog. Not least because of the interesting work of one researcher in particular - Emily Severance - as a name behind some potentially very important research on how food, infection and immune function might come together in complicated conditions such as [some] schizophrenia and [some] bipolar disorder (see here and see here).

Continuing their 'gut-brain' theme (oh, yes) new research from Prof/Dr Severance and colleagues [1] has been published observing that "sex-specific C. albicans immune responses were evident in psychiatric disorder subsets." C. albicans refers to Candida albicans, a fungus that I'm sure most people will have heard of at one time or another if not only as a function of those TV adverts for preparations to combat C. albicans when tied into yeast infection.

On this most recent occasion, researchers were testing the idea of "C. albicans as a new candidate infectious disease target for studies of schizophrenia and bipolar disorder" as a extension of other research talking about 'bacterial dysbioses' potentially contributing "to C. albicans overgrowth by failing to provide the competition needed to keep the fungus in check." If you're furrowing your brow about the thought that the trillions of wee beasties that call us home (the gut microbiome) might exert an effect on behavioural or psychiatric presentation, relax yourself slightly: interest is growing in this area [2] following on from other investigations in other areas (see here).

So, researchers: "measured and compared IgG antibodies directed against this fungus in two psychiatric cohorts: one composed of 261 people with schizophrenia, 270 with bipolar disorder and 277 individuals without a history of psychiatric disorder; the other cohort was composed of 139 people with first-episode schizophrenia, 78 of whom were antipsychotic naive." They also examined cognitive symptoms and took into account various factors that might act as confounders onwards to the idea that IgG antibodies to C. albicans *might* be considered a risk factor for either schizophrenia or bipolar disorder.

Results: well it wasn't as straight-forward as blanket saying that the presence of IgG antibodies (seropositivity) or quantitative levels of these antibodies to C. albicans equals schizophrenia or bipolar disorder (or not-schizophrenia or not-bipolar disorder). There was nothing statistically significant between the various groupings in the cohorts included for study. But... when the groups were categorised according to sex (gender), researchers reported "significant elevations of C. albicans IgG in males with schizophrenia and bipolar disorder compared with male controls."

Further analyses suggested that there may be some 'associations' with other variables examined across the sexes when it came to those IgG antibodies ("females with schizophrenia who were C. albicans IgG-seropositive performed more poorly on these [cognitive] tests than did females with schizophrenia who were C. albicans IgG-seronegative or than female controls") and it appeared that antipsychotic medication use did little to impact on the findings. The bottom line: "antibodies directed against the opportunistic fungal pathogen, C. albicans, were elevated in distinct subsets of individuals with psychiatric disorders" and minus any sweeping generalisations, a research agenda incorporating brain, immune function, gut and also contents of the gut could be indicated in future study. This of course set among the idea that schizophrenia might be better represented by the more plural 'schizophrenias'.

Some of the media around this study and its findings are perhaps a little 'sensational' as per the headline asking: Is a sexually transmitted yeast infection making people mentally ill? I perhaps wouldn't go as far as that at the moment given that C. albicans is present in everyone(?) and overgrowth of such a yeast is not necessarily due to sex or related activities. Yes, certain sexual diseases can manifest as psychological symptoms but an important basis of the Severance study is that intrinsic factors such as gut dysbiosis might start a chain reaction whereby C. albicans is able to flourish and becomes rather more systemic and pathogenic linked to the presentation of behavioural symptoms. Or at least that is part of the hypothesis requiring further testing...

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[1] Severance EG. et al. Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder. npj Schizophrenia 2016; 2: 16018.

[2] Dinan TG. et al. Genomics of schizophrenia: time to consider the gut microbiome? Mol Psychiatry. 2014 Dec;19(12):1252-7.

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Severance, E., Gressitt, K., Stallings, C., Katsafanas, E., Schweinfurth, L., Savage, C., Adamos, M., Sweeney, K., Origoni, A., Khushalani, S., Leweke, F., Dickerson, F., & Yolken, R. (2016). Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder npj Schizophrenia, 2 DOI: 10.1038/npjschz.2016.18

Add-on nutraceuticals for depression?

It came as no surprise to me that the systematic review and meta-analysis article by Jerome Sarris and colleagues [1] found what it did in relation to the use of [certain] adjunctive (add-on) nutraceuticals alongside antidepressants to reduce depressive symptoms: some of them might actually be clinically useful.

With no medical or clinical advice given or intended, the authors report that "adjunctive use of SAMe, methylfolate, omega-3, and vitamin D with antidepressants" might be something to consider "for improving inadequate response to antidepressants." Dr Sarris was one among many authors who contributed to the 'personal view' paper titled: 'Nutritional medicine as mainstream in psychiatry' [2] which was also covered a while back on this blog (see here). This latest addition to that and other opinions [3] which covered the peer-reviewed literature on a variety of nutrients also found something of a mixed bag of results for various other compounds including the aromatic amino acid tryptophan, zinc, folic acid and vitamin C.

Quite a bit more science needs to be done in this area, not least around the hows and whys that the various preparations might exert some effect. Vitamin D has of course been covered quite a bit on this blog in relation to something like depression (see here for example) so that particular nutraceutical might already have a research head start compared to others. I'm also minded to suggest that the involvement of something like SAMe (S-adenosylmethionine) as an add-on treatment might also imply a role for epigenetic variables in relation to at least some depression [4]. And then there is the question of who might be best responders to such nutraceutical use which implies heterogeneity and possible plural depressions...

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[1] Sarris J. et al. Adjunctive Nutraceuticals for Depression: A Systematic Review and Meta-Analyses. American Journal of Psychiatry. 2016. April 26.

[2] Sarris J. et al. Nutritional medicine as mainstream in psychiatry. Lancet Psychiatry. 2015 Mar;2(3):271-4.

[3] Sarris J. et al. International Society for Nutritional Psychiatry Research consensus position statement: nutritional medicine in modern psychiatry. World Psychiatry. 2015 Oct;14(3):370-1.

[4] McGowan PO. & Kato T. Epigenetics in mood disorders. Environ Health Prev Med. 2008 Jan;13(1):16-24.

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Sarris J, Murphy J, Mischoulon D, Papakostas GI, Fava M, Berk M, & Ng CH (2016). Adjunctive Nutraceuticals for Depression: A Systematic Review and Meta-Analyses. The American journal of psychiatry PMID: 27113121

On the question of valproate use and pregnancy

I very much want to stress the point that 'no medical or clinical advice is given or intended' on this blog before proceeding further with discussions based on the commentary paper by Richard Balon & Michelle Riba titled: 'Should Women of Childbearing Potential Be Prescribed Valproate?' [1].

Valproate, as in preparations like sodium valproate, has been a particular talking point in recent years as a consequence of something of an emerging body of peer-reviewed science suggesting that its use during pregnancy may place offspring at some elevated risk for various neurodevelopmental outcomes (see here). The Medicines and Healthcare Products Regulatory Agency (MHRA) here in Blighty issued some revised guidance last year (2015) 'strengthening' warnings about the use of valproate under certain circumstances. This follows some research history on how for example, a valproic acid mouse model of autism has been used as "environmentally induced ASD [autism spectrum disorder] models in rodents" [2] for quite a few years.

Balon & Riba cover various points in the debate about valproate use during pregnancy specifically focused on the known "teratogenic outcome[s]" that have been reported down the years bearing in mind that valproate serves an important (sometimes life-saving) use. I was particularly struck by the 'interference' with folic acid metabolism discussed in their commentary on the basis of some science in this area [3]. With that pinch of salt at the ready, some readers might already know that folate metabolism has some research history in autism circles (albeit not necessarily settled science) and indeed, continues to make scientific waves. Accepting that valproate might have more than one action when potential offspring outcomes are concerned (see here), I do wonder if further research focus could be directed on the folate aspect of the drug when it comes to risk of various neurodevelopmental diagnoses for example?

The question of valproate use outside of the management of epilepsy is a focus of the Balon/Riba article; specifically "used in acute mania or in prophylaxis of bipolar disorder." Bearing in mind that various other medicines are available to manage these conditions and that "unplanned pregnancies are common in this population" [4] I don't think it's out of place for the authors to "recommend that the FDA and valproate manufacturers declare valproate contraindicated in women of childbearing age and issue guidelines for counseling women of childbearing potential with bipolar disorder." Indeed, NICE here in England, seem to have taken a lead on this...

If in doubt, please consult with your medical physician.

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[1] Balon R. & Riba M. Should Women of Childbearing Potential Be Prescribed Valproate? J Clin Psychiatry. 2016; 77: 525–526.

[2] Ergaz Z. et al. Genetic and non-genetic animal models for Autism Spectrum Disorders (ASD). Reprod Toxicol. 2016 Apr 30. pii: S0890-6238(16)30077-6.

[3] Fathe K. et al. Brief report novel mechanism for valproate-induced teratogenicity. Birth Defects Res A Clin Mol Teratol. 2014 Aug;100(8):592-7.

[4] Marengo E. et al. Unplanned pregnancies and reproductive health among women with bipolar disorder. J Affect Disord. 2015 Jun 1;178:201-5.

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Balon R, & Riba M (2016). Should women of childbearing potential be prescribed valproate? a call to action. The Journal of clinical psychiatry, 77 (4), 525-6 PMID: 27137420

Brain GABA levels and autism meta-analysed

The paper by Remmelt Schür and colleagues [1] provides some (brief) blogging fodder today and the observation that following a "systematic literature review and meta-analysis of 1 H-MRS studies" brain GABA levels were found to be significantly lower in cases of autism spectrum disorder (ASD) than compared to control (not autism) populations.

GABA - gamma-Aminobutyric acid - has been something of interest for quite a few years in autism research circles (see here). It's particular role as an inhibitory neurotransmitter has perhaps been where the lion's share of research has been targeted, bearing in mind it's actions might extend quite a bit further [2]. Indeed, whilst the over-representation of epilepsy in cases of autism (see here) hints at a possible dual role for GABA in relation to autism, I'd be minded to suggest that far more complicated processes might also be at work for some people (see here).

Schür and colleagues surveyed the peer-reviewed research literature for several developmental and psychiatric labels with measured brain levels of GABA in mind. They concluded that outside of autism, there was also some evidence for lower levels of brain GABA in those diagnosed with major depressive disorder (MDD) too (albeit those still presenting with symptoms). Further: "No significant differences in GABA levels were found in bipolar disorder, panic disorder, PTSD [post-traumatic stress disorder], and ADHD [attention-deficit hyperactivity disorder] compared with controls."

Minus any sweeping generalisations about how GABA levels could be a 'uniting' feature of autism and MDD (even though there may be overlap including at a clinical level) I do find the possibility of shared physiology to be an important one. Not least because of discussions about how interventions "aimed at either autism symptoms or symptoms of depression may improve the other" [2] could very much include GABA as one of several potential clinical parameters.

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[1] Schür RR. et al. Brain GABA levels across psychiatric disorders: A systematic literature review and meta-analysis of 1 H-MRS studies. Hum Brain Mapp. 2016 May 4.

[2] Andersen PN. et al. Associations Among Symptoms of Autism, Symptoms of Depression and Executive Functions in Children with High-Functioning Autism: A 2 Year Follow-Up Study. J Autism Dev Disord. 2015 Aug;45(8):2497-507.

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Schür RR, Draisma LW, Wijnen JP, Boks MP, Koevoets MG, Joëls M, Klomp DW, Kahn RS, & Vinkers CH (2016). Brain GABA levels across psychiatric disorders: A systematic literature review and meta-analysis of 1 H-MRS studies. Human brain mapping PMID: 27145016

Siblings of probands with autism: preferential screening suggested?

"Psychiatric and neurodevelopmental disorders cluster among siblings of probands with ASD [autism spectrum disorder]."

That was the research bottom line presented in the paper by Elina Jokiranta-Olkoniemi and colleagues [1] who extracted data from the Finnish Prenatal Study of Autism and Autism Spectrum Disorders (FIPS-A). FIPS-A has been mentioned previously on this blog (see here) but this time around the aim was to look not at the various risk factors potentially associated with receipt of an autism diagnosis, but rather how siblings of those with autism might require some preferential screening for a variety of potential psychiatric and/or neurodevelopmental labels. I know that might not make great reading but burying ones head in the sand is not likely to do anyone any good.

With a starting participant sample in the thousands - "31, 2005, who received a diagnosis of ASD" - researchers matched cases with asymptomatic (not autism) controls to a ratio of 4:1. "This nested case-control study included 3578 cases with ASD with 6022 full siblings and 11 775 controls with 22 127 siblings from Finnish national registers." Various psychiatric and behavioural diagnoses were searched for among siblings of those with autism and compared with rates among control participant siblings. An adjusted risk ratio was generated; authors also taking into account the various ASD sub-diagnoses (many of which have been subsumed under the latest DSM-5 definition of autism).

Results: as per the opening sentence, siblings of those diagnosed with autism were at a significantly increased risk of various psychiatric and neurodevelopmental outcomes. Around 10% of siblings of those with autism were diagnosed with an ASD tallying with what has been previously reported in the peer-reviewed literature on familial recurrence (see here). This compared with the similarly standard 1% of siblings of asymptomatic controls who were diagnosed with an ASD. Actually, 1% might not be the standard any longer...

Other associations were also noted; so learning and coordination disorders were reported in around 15% of siblings of those with autism compared with 6% in control siblings. Similar patterns were noted with regards to attention-deficit hyperactivity disorder (ADHD) and interestingly, tic disorders too (a particular interest to this blog). The bottom line again being that siblings of those with autism might have something of an increased risk of receiving various developmental or behavioural diagnoses.

The authors conclude that when it comes to discussions about aetiology, there may be some common risk factors that predispose to the various labels included for study. Of course this is not necessarily new news as per other research looking at 'overlapping' structural genetics for example (see here) and the realisation that a diagnosis of autism is by no means protective against other conditions occurring (see here). Indeed, other research published in the same journal hints at some important genetic overlap when it comes to autism and other diagnoses [2] which may be particularly relevant (see here). If there is anything that I would add to any future research agenda it would be some way of incorporating the concept of the broader autism phenotype (BAP) into proceedings (see here) and also the inclusion of more somatic diagnoses (see here) as well as neurodevelopmental and psychiatric as a means to search for overlapping variables. As for clinical practice, well to reiterate again, the implication is to potentially offer preferential screening for a variety of neurodevelopmental and/or psychiatric labels when autism appears in the family...

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[1] Jokiranta-Olkoniemi E. et al. Risk of Psychiatric and Neurodevelopmental Disorders Among Siblings of Probands With Autism Spectrum Disorders. JAMA Psychiatry. 2016. May 4.

[2] Goes FS. et al. Exome Sequencing of Familial Bipolar Disorder. JAMA Psychiatry. 2016. April 27.

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Jokiranta-Olkoniemi, E., Cheslack-Postava, K., Sucksdorff, D., Suominen, A., Gyllenberg, D., Chudal, R., Leivonen, S., Gissler, M., Brown, A., & Sourander, A. (2016). Risk of Psychiatric and Neurodevelopmental Disorders Among Siblings of Probands With Autism Spectrum Disorders JAMA Psychiatry DOI: 10.1001/jamapsychiatry.2016.0495

Immigrant background and risk of offspring ADHD

"The likelihood of being diagnosed with ADHD [attention-deficit hyperactivity disorder] was significantly increased among children of two immigrant parents... and children of an immigrant father."

So said the findings published by Venla Lehti and colleagues [1] continuing a research theme from this authorship group (see here) on how immigration might, for various reasons, bring about an increased or decreased risk of certain behavioural and/or psychiatric outcomes. This time around ADHD was in the research spotlight and how analysis "based on a national birth cohort" numbering in the tens of thousands suggested there may be more to see when it comes to a diagnosis in light of parental immigration status.

The records of over 10,000 children/young adults born between 1991 and 2005 and diagnosed with ADHD by 2011 were compared with matched - not ADHD - controls (n=39,124) taking into account "parents' country of birth and native language." Various other variables were added into the subsequent statistical mix including "time since maternal migration." As per that opening sentence, there did appear to be more to see when it came to immigration status and offspring outcome; where a child was born to two immigrant parents, the adjusted odds ratios were not to be sniffed at (4.7, 95% CI 3.4-6.6) insofar as an increased risk of offspring ADHD diagnosis.

I was also taken by another finding reported by Lehti et al: "Children, whose parents were born in countries with low Human Development Index (HDI), were more often diagnosed with ADHD." The HDI is a sort of summary measure taking into account variables such as education, life expectancy and income ranking countries in terms of their human development. Quite a few of the countries in places like sub-Saharan Africa, North Africa and Latin America rank 'low' on the HDI and also seemed to tally with the specific data on country of origin when it came to the Lehti findings.

As interesting as the current findings are, the universal idea that ADHD risk might be elevated in children of immigrant families is by no means a settled issue [2]. As per my sentiments on quite a few issues covered on this blog, sweeping generalisations are not required. I would however like to see a lot more research done on this issue focused not just on 'risk' of diagnosis but also around the possible factors that might contribute to immigrant offspring being more readily diagnosed with something like ADHD. Lehti et al suggest that their results might indicate "increased exposure to environmental risk factors, differences in the use of health services, or challenges in diagnosing immigrants' children" as being relevant. Certainly one could draw on work in other clinical areas as being potentially relevant (see here for example) to the current findings including potential biological correlates too (see here and see here).

One further point that might also be particularly important to the Lehti findings: that linked to socio-economic status (SES) and how that seems to affect risk of a diagnosis of ADHD more generally (see here). Without generalising about any relationship between immigration status and SES, it is not outside the realms of possibility that at least for some migrants, entry to places like Finland where the current research was carried out, might not be accompanied by significant wealth for example. SES deprivation and ADHD diagnosis is an area of continuing interest [3]; indeed, with recent political situations in mind, one wonders whether future surveillance may be very much indicated.

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[1] Lehti V. et al. Association between immigrant background and ADHD: a nationwide population-based case-control study. J Child Psychol Psychiatry. 2016 May 2.

[2] Tan TX. Emotional and Behavioral Disorders in 1.5th Generation, 2nd Generation Immigrant Children, and Foreign Adoptees. J Immigr Minor Health. 2016 Mar 14.

[3] Russell AE. et al. The Association Between Socioeconomic Disadvantage and Attention Deficit/Hyperactivity Disorder (ADHD): A Systematic Review. Child Psychiatry Hum Dev. 2016 Jun;47(3):440-58.

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Lehti V, Chudal R, Suominen A, Gissler M, & Sourander A (2016). Association between immigrant background and ADHD: a nationwide population-based case-control study. Journal of child psychology and psychiatry, and allied disciplines PMID: 27133554

More [metabolomic] evidence for dysbiosis and some autism?

The paper by Xiyue Xiong and colleagues [1] (open-access available here) took my attention recently and some further evidence contributory to the idea that the trillions of wee beasties that call our gastrointestinal (GI) tract home - collectively known as the gut microbiome - might have some important links to at least 'some' autism.

Describing the results of "a GC/MS based metabolomic approach"  - GC-MS being gas chromatography-mass spectrometry and metabolomic(s) being the analysis of 'small molecule metabolites found in biological fluids such as blood, saliva and urine' - the authors report results based on analysis of urine specimens for some 62 children diagnosed with an autism spectrum disorder (ASD) compared to 62 'not-autism' controls. Bearing in mind that quite a few of the compounds normally found in urine are linked to the goings-on in the gut microbiome, the authors ensured that "Children included in the study had no antianaerobic drug use history" (i.e. certain types of antibiotics were not used).

Results: "Three compounds identified as 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA), 3-hydroxyphenylacetic acid (3HPA), and 3-hydroxyhippuric acid (3HHA) were found in higher concentrations in autistic children than in the controls." I was rather interested in the HPHPA finding in particular given that it has previously appeared on this blog in relation to autism and the gut microbiome (see here) following other peer-reviewed findings [2]. The watchword on that previous post was 'dysbiosis' and how alterations in the relative levels of certain gut bacterial species might have some rather intriguing outcomes [3]. The idea therefore being that the action of certain types of bacteria on the proposed starting material for HPHPA (the aromatic amino acids phenylalanine and tyrosine) might influence metabolism and lead to elevations in this metabolite. At this point I'll also refer you to some other musing on research on another aromatic amino acid (tryptophan) that might also be 'autism-relevant' (see here).

Indeed to further test the idea of a gut microbial link to the elevations noted in HPHPA and related metabolites, Xiong et al provide further details: "Fifty HPHPA-positive autistic children (9/50 patients 3HPA-positive and 17/50 patients 3HHA-positive) were selected for oral vancomycin treatment at standard age-appropriate dosages (50 mg/kg/d, 30 days as one therapeutic course) followed by supplement therapy with Bifidobacterium agent (Bifidobacterium BB-12, 2 pills a day)." Use of vancomycin - a quite powerful antibiotic indicated for the treatment of 'Clostridium difficile–associated Disease' [4] among other things - is not unheard of in autism research and practice circles (see here) and this time around there were significant decreases in the levels of HPHPA and related metabolites "which indicated that these compounds may also be from gut Clostridium species." Further, when vancomycin was stopped: "3–6 months later, the concentration of HPHPA almost recovered to its initial level in 3 patients and recovered to 0.08–0.45 times their initial values in 12 patients." Authors also noted that some behavioural scores might have been affected by the use of vancomycin that could be construed along the same lines as when Sandler et al reported on the use of vancomycin with 'regressive-onset autism' in mind [5].

The authors also add in some details about how "measurements of the three metabolites are strong predictors of ASDs and support the potential clinical utility for identifying a subgroup of ASDs subjects in whom disordered phenylalanine metabolism may be a salient characteristic." On this point I'm not convinced that on the basis of 60 or so children and with 3 metabolites in mind (out of the thousands that we excrete everyday influenced by all manner of 'internal' and 'external' forces) there is biomarker potential for 'all autism' just yet. I am in agreement that 'disordered phenylalanine metabolism' for a subgroup on the autism spectrum is a possibility based on the use of 'phenylalanine mopping up' compounds in other peer-reviewed work (see here) for example. But much more research is indicated...

These are interesting results that, yet again, require independent replication. Because I am a bit of stickler when it comes to all-things metabolomics (especially where mass spectrometry is involved) I might be inclined to mention about how adjustment using creatinine might have issues when it comes to autism (see here) which could affect the final quantification of metabolites. I might also suggest that the GC-MS system used and the urine sample pre-treatment applied before analysis could be 'up-graded' taking into account more accurate detection methods (e.g. q-ToF mass spectrometry with liquid chromatography separation) with a greater focus on features like accurate mass.

But don't let me put you off from the idea that marrying metabolomics and microbiomics could be a good autism research idea. Although on the topic of whether we might be able to 'alter' our microbiomes/metabolome in ways other than the use of potent antibiotics, the jury is still out [6] bearing in mind how diet might affect results...

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[1] Xiong X. et al. Urinary 3-(3-Hydroxyphenyl)-3-hydroxypropionic Acid, 3-Hydroxyphenylacetic Acid, and 3-Hydroxyhippuric Acid Are Elevated in Children with Autism Spectrum Disorders. Biomed Res Int. 2016;2016:9485412.

[2] Shaw W. Increased urinary excretion of a 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA), an abnormal phenylalanine metabolite of Clostridia spp. in the gastrointestinal tract, in urine samples from patients with autism and schizophrenia. Nutr Neurosci. 2010 Jun;13(3):135-43.

[3] Rogers GB. et al. From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways. Molecular Psychiatry. 2016. April 19.

[4] Shen EP. & Surawicz CM. Current Treatment Options for Severe Clostridium difficile–associated Disease. Gastroenterology & Hepatology. 2008;4(2):134-139.

[5] Sandler RH. et al. Short-term benefit from oral vancomycin treatment of regressive-onset autism. J Child Neurol. 2000 Jul;15(7):429-35.

[6] Kristensen NB. et al. Alterations in fecal microbiota composition by probiotic supplementation in healthy adults: a systematic review of randomized controlled trials. Genome Medicine. 2016; 8: 52.

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Xiong X, Liu D, Wang Y, Zeng T, & Peng Y (2016). Urinary 3-(3-Hydroxyphenyl)-3-hydroxypropionic Acid, 3-Hydroxyphenylacetic Acid, and 3-Hydroxyhippuric Acid Are Elevated in Children with Autism Spectrum Disorders. BioMed research international, 2016 PMID: 27123458