A recent review published online as an 'article in press' in the journal Translational Psychiatry suggests that gut dysbiosis may contribute to stress-related psychiatric disorders, according to a July 20 report. The review discusses how alterations in the gut microbiome may change the production of metabolites that influence neural, endocrine, immune, and epigenetic signaling between the gut and brain. These changes can affect cognitive and emotional function and potentially contribute to conditions such as anxiety, depression, or post-traumatic stress disorder.
The authors outline that chronic stress may predispose individuals to these psychiatric conditions, which together impose a substantial global health burden. They say current diagnostic and treatment approaches remain largely empirical with limited accuracy and efficacy. "Further investigations are required to improve the understanding of biological mechanisms underlying the association between stress and psychiatric disorders to help develop more targeted strategies and ultimately improve patient outcomes," researchers said.
The review summarizes preclinical and clinical evidence linking disruptions in intestinal microbiome structure or function with onset or progression of stress-related psychiatric disorders. Gut microbes produce several classes of metabolites—such as bile acids, short-chain fatty acids (SCFAs), monoamine- and amino acid-related compounds—that influence key signaling pathways connecting the gut with the brain through immunological, endocrine, neural, and epigenetic processes.
Altered metabolite profiles may increase intestinal permeability, allowing microbial products like lipopolysaccharide into circulation; these products could promote inflammatory signaling both peripherally and centrally. The review also notes that SCFAs help maintain intestinal barrier integrity; lower butyrate levels have been associated with depression across some studies. Animal models suggest supplementation with certain SCFAs can improve mood- or cognition-related behaviors.
While most clinical evidence concerns depression rather than anxiety or PTSD directly, interventions such as dietary changes, exercise, probiotics, prebiotics, traditional Chinese medicine practices, or fecal microbiota transplantation are being explored for their potential effects on the gut-brain axis. However, researchers say, "their clinical efficacy... remains uncertain" due to variability among individuals and inconsistent findings across studies.
The authors conclude by calling for longitudinal human studies integrating multi-omics data to clarify causal relationships between microbiome alterations and disease trajectories.
