From the little research I've done, it looks like the bifidobacterium genus, in particular certain strains of bifidobacterium longum [0,1] and infantis [2], hav

From the little research I've done, it looks like the bifidobacterium genus, in particular certain strains of bifidobacterium longum [0,1] and infantis [2], have favorable effects on IBS and anxiety. Interestingly, in [1] they noted that it was able to normalize low BDNF levels, which is one hypothesis as to how SSRIs treat anxiety and depression. However, I picked out my probiotic specifically because it has those species (among many others), and you read what happened. [0] http://www.ncbi.nlm.nih.gov/pubmed/17172187 http://www.ncbi.nlm.nih.gov/pubmed/17172187 [1] http://www.apa.org/monitor/2012/09/gut-feeling.aspx http://www.apa.org/monitor/2012/09/gut-feeling.aspx [2] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2886445/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2886445/