The intestinal microbiota associated with prognosis after a psychotic episode


The intestinal microbiota could play a role in psychosis remission. While change in its composition is already associated with several mental illnesses like depression, Parkinson’s or even autism, an international team studied this link in subjects who presented a first psychotic episode. To do so, they recruited 28 patients aged 18 to 40 who experienced delirium and hallucinations as well as 16 healthy subjects as controls. They analyzed the composition of the intestinal microbiota of all the participants at baseline and then saw the patients again after two months and one year to assess their mental health status. This study allowed them to describe clear differences between the intestinal microbiota of patients and controls, in particular regarding the Lactobacillus group. The more numerous the bacteria of this group, the more severe the symptoms and the more impaired the overall functioning of the patients. Another finding was that the patients for whom the dysbiosis was the most pronounced responded less well to treatments and had reduced chances of remission at two months and one year. According to the authors, this dysbiosis was not attributable to differences in diet or the influence of medications. These observations confirm the importance of better investigating the links between the microbiota and psychotic diseases and suggest the interest of bacterial flora to improve the chances of recovery.



Schwarz E. et al. Analysis of microbiota in first episode psychosis identifies preliminary associations with symptom severity and treatment response. Schizophr Res. 2017 Apr 22. pii: S0920-9964(17)30204-9.