Recent studies by the Catholic University of Leuven in Belgium also investigated the relationship between microbiom, our brain and behaviour.2 The differences in stool were analysed in over 2,000 healthy and depressed people. The results suggest that certain intestinal bacteria may help against depression. At least there was a deficiency of the bacterial species in the intestines of depressive people:
The Belgian studies also concluded that the genes of certain intestinal bacteria are involved in the formation of the messenger substance GABA. Others, however, degrade the signaling substance dopamine. On the basis of disturbances of the intestinal flora, depression and other mental ailments may in future perhaps be recognised at an early stage and thus treated specifically. Whether the lack of intestinal bacteria actually triggers the depression or whether more intestinal bacteria die as a result of a depression is to be clarified in follow-up studies.
2. Valles-Colomer M, Falony G, Darzi Y, et al. The neuroactive potential of the human gut microbiota in quality of life and depression. Nature Microbiology 2019:4, 623-632, https://www.nature.com/articles/s41564-018-0337-x ↩