The positive effects of 12 weeks of probiotics and vitamin D in chronic schizophrenia?

The findings reported by Amir Ghaderi and colleagues [1] (open-access) provide the blogging fodder today, and the results of a study looking at a "novel combination of vitamin D and probiotic on metabolic and clinical symptoms in chronic schizophrenia." Said probiotic formulation contained "Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum (each 2 × 109)" and was delivered over a period of 12 weeks alongside a vitamin D supplement - "50,000 IU vitamin D3 every 2 weeks" - utilising a "randomized, double-blind, placebo-controlled trial" design. We are also told that the trial protocol was "retrospectively registered."

The Ghaderi study wasn't solely focused on what their combined intervention might do for the 'clinical symptoms' of schizophrenia despite this being a prominent part of the results obtained. They also wanted to examine things like "biomarkers of oxidative stress and cardiometabolic risk in chronic schizophrenia." This was done via the measurement of marker compounds pertinent to establishing total antioxidant capacity, total glutathione levels and high-sensitivity C-reactive protein (hs-CRP) among other things.

Results: first things first, vitamin D supplementation raised vitamin D levels in those who received the vitamin D + probiotic supplement. Not exactly an unexpected result I grant you, but important from the point of view that any subsequent findings *could* be linked to those increasing vitamin D levels. Further: "Vitamin D and probiotic co-supplementation was associated with a significant improvement in the general... and total PANSS scores." PANSS stands for the Positive and Negative Syndrome Scale and has some important uses in the context of schizophrenia, and the presentation of positive and negative symptoms. That all being said, the authors also mention how their supplementation combination did not seemingly affect scores on another measure included in the study - the Brief Psychiatric Rating Scale (BPRS) - which kinda demonstrates that vitamin D + probiotics is not a panacea for every aspect of schizophrenia.

Researchers also report on how their combined supplement also *correlated* with a some changes in those oxidative stress and cardiometabolic risk measures included for study in line with other study results (see here). There's quite a bit of data so I won't provide details. Suffice to say that some of them might be 'positively' important to those health inequalities that seem to follow a diagnosis of schizophrenia (see here).

What else? Well, I can't seem to find too much in the way of side-effects details in the Ghaderi paper so I'm assuming that it wasn't a significant issue. The fact that participants in the study were "being hospitalized during the intervention" means that they were, I assume, being monitored with greater assiduity than for example if they were in the community, including looking for potential side-effects.

And with that, and the requirement for further study (see here and see here), I say no more...

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[1] Ghaderi A. et al. Clinical and metabolic response to vitamin D plus probiotic in schizophrenia patients. BMC Psychiatry. 2019; 19:77.

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