Saturday, 27 February 2016

C-section and the microbial transplant

I'm pretty sure that the paper by Maria Dominguez-Bello and colleagues [1] speaks for itself when describing the results of "a pilot study in which infants delivered by C-section [Caesarean section] were exposed to maternal vaginal fluids at birth." If you need a graphic, some coverage of the research in the New York Times helpfully provides a visual aid (see here).

The long-and-short of it is that following some concerns that infants delivered via C-section might be missing out on some valuable exposure to their mother's microbial passengers [2] as a function of their by-passing the birth canal and beyond, the use of a "vaginal microbial transfer" might be an option. Detailing results based on a small number of births - 11 born by C-section (planned or elective) and 7 via the more traditional route - researchers report what happened when 4 of the C-section infants were swabbed with previously collected gauze containing mum's bacterial passengers. Swabbing by the way, was done on various parts of the infant's body.

The authors concluded that: "Similarly to vaginally delivered babies, the gut, oral and skin bacterial communities of these newborns [swabbed C-section infants] during the first 30 d[ays] of life was enriched in vaginal bacteria—which were underrepresented in unexposed C-section–delivered infants." That being said, the results appeared to show that whilst swabbing was good at delivering a microbial transplant for C-section infants, it was no substitute for the real thing (a vaginal birth) bacterially-speaking. I might also add that important variables such as breastfeeding (or not) can also influence the constitution of our gut bacteria (see here).

There is some media chatter about this study and onwards what the longer-term effects might be in terms of health and well-being in the context of how our bacterial masters may show various health/disease links [3]. I'd be interested to see how this cohort and other larger ones fare as a result. I do however, have a word of caution to add to proceedings alongside others it seems (see here).

Accepting that a vaginal microbial transfer is not the same as the more 'popular' talking point that is a faecal microbiota transplant, and that the bacteria that colonise the gut may not necessarily be the same as that colonising other parts of the body, I'm minded to direct readers to a post not-so-long-ago covering weight gain following poo(p) transplant (see here). I don't think the specific 'obesogenic' bacteria were isolated in the case report by by Neha Alang and Colleen Kelly [3] or indeed, whether other elements such as the gut virome may have exerted some effect on patient weight gain following "receiving stool from a healthy but overweight donor." But one question might be to ask whether a similar 'process' could potentially be pertinent to the swabbing of C-section infants?

OK, I appreciate that there has been some research discussion about how C-section babies *might* be slightly more prone to obesity in later life (see here). But if one assumes that outside of the typical risk factors linked to obesity, there may be a microbial link too, is it not inconceivable that an early-days microbial transplant from a mum who is herself overweight or obese at the time of birth might potentially 'transmit' the basis of such weight problems to offspring too? Indeed, with all the chatter about microbes and mood these days (see here for example) one could potentially stretch the 'bacterial association' even further...

I'll leave you with those thoughts and some (new) music from the Leppard (hopefully really not a "nuclear waste of time").


[1] Dominguez-Bello MG. et al. Partial restoration of the microbiota of cesarean-born infants via vaginal microbial transfer. Nature Medicine. 2016. Feb 2.

[2] Biasucci G. et al. Cesarean delivery may affect the early biodiversity of intestinal bacteria. J Nutr. 2008 Sep;138(9):1796S-1800S.

[3] Alang N. & Kelly CR. Weight Gain After Fecal Microbiota Transplantation. Open Forum Infect Dis. 2015; 2: 1.

---------- Dominguez-Bello MG, De Jesus-Laboy KM, Shen N, Cox LM, Amir A, Gonzalez A, Bokulich NA, Song SJ, Hoashi M, Rivera-Vinas JI, Mendez K, Knight R, & Clemente JC (2016). Partial restoration of the microbiota of cesarean-born infants via vaginal microbial transfer. Nature medicine PMID: 26828196