A systematic review examined data from 1,040 patients with inflammatory bowel disease. The researchers looked at how gut microbiota characteristics relate to symptoms of anxiety and depression. They also analyzed microbial diversity, pro-inflammatory bacteria, and short-chain fatty acid-producing bacteria. The study included psychological interventions and microbiota-targeted treatments like probiotics and fecal microbiota transplantation.
The analysis showed that reduced microbial diversity was associated with higher anxiety and depressive symptoms. Enrichment of pro-inflammatory bacteria and depletion of bacteria that produce short-chain fatty acids were also linked to these mental health symptoms. Microbiota-targeted interventions appeared to modulate microbial composition and reduce anxiety and depression scores in some cases. Psychological interventions with microbiota profiling suggested potential effects on gut microbial composition.
The findings remain heterogeneous, meaning results varied across different studies. Associations between gut bacteria and mental health may not be fully explained by disease activity. The study could not clarify directionality or confirm causal hypotheses. Future studies are needed to test these ideas further. Microbiota-targeted interventions and psychological therapies may represent promising strategies for managing psychological comorbidities in inflammatory bowel disease.