Recently I have come across several articles citing psychoactive bacteria (where the bacteria was from a probiotic). I thought it would be fun to do a review of such. Psychobiotics: a novel class of psychotropic. “…including Bifidobacterium infantis ….Evidence is emerging of benefits in alleviating symptoms of depression and in chronic fatigue syndrome.”
Also see my earlier post on depression and diet
- “We previously have demonstrated that administration of Lactobacillus rhamnosus (JB-1) to healthy male BALB/c mice, promotes consistent changes in GABA-A and -B receptor sub-types in specific brain regions, accompanied by reductions in anxiety and depression-related behaviors.”  
- “Within minutes of application, JB-1 increased the constitutive single- and multiunit firing rate of the mesenteric nerve bundle, but Lactobacillus salivarius (a negative control) or media alone were ineffective.” 
- “These results suggest that chronic ingestion of Lactobacillus plantarum strain PS128 could ameliorate anxiety- and depression-like behaviors and modulate neurochemicals related to affective disorders.Thus PS128 shows psychotropic properties and has great potential for improving stress-related symptoms.” 
- “PS128 is safe and could induce changes in emotional behaviors…These findings suggest that daily intake of the L. plantarum strain PS128 could improve anxiety-like behaviors and may be helpful in ameliorating neuropsychiatric disorders.”
- “One study showed improved mood in healthy volunteers following 3-week consumption of a probiotic-containing milk drink that contained Lactobacillus casei Shirota” 
- “administration of the probiotic, L. casei Shirota, decreased anxiety in patients with chronic fatigue syndrome.”
- “L. helveticus and B. longum, for 30 days demonstrated significantly less psychological distress,” 
- “higher anxiety scores in IBS patients and healthy controls were associated with lower fecal microbial diversity supporting a link between microbiota and psychological state” 
- “Gut microbiota alterations have also been reported in a substantial number of children with autism, particularly citing a 10-fold increase in Clostridium numbers as well as greater diversity” 
- “Alistipes, a genus in the phylum of Bacteroidetes was overrepresented in depressed patients.”
- “Alistipes is also overrepresented in chronic fatigue syndrome [2013 Kenny De Meirleir]and in irritable bowel syndrome (IBS) “
- “it has been shown that Alistipes levels and other gut microbiota can be modified through dietary intervention” i.e. less meat.
- soluble dietary fiber (soluble resistant maltodextrin) may decrease  – likely any significant (MAJOR) increase in fiber will help.
- Bacillus subtilis may increase Alistipes 
- “the three β-lactam antibiotics(Ceftriaxone Sodium, Cefoperazone/Sulbactam and meropenem), showed consistency in inhibiting Papillibacter, Prevotella and Alistipes while inducing massive growth of Clostridium.”
Above we found that there is evidence that one common probiotic (Bacillus Subtilis) may actually make depression worst! Reducing meat and increase fiber in a major shift may also improve depression. All of the Lactobacillus cited above are acceptable for CFS (but L. helveticus is questionable).