The Gut Microbiome and Diet in Psychiatry: Focus on Depression

Sarah Dash; Gerard Clarke; Michael Berk; Felice N. Jacka


Curr Opin Psychiatry. 2015;28(1):1-6. 

In This Article

Diet and Mental Health

There have been a rapidly increasing number of observational studies documenting cross-sectional and prospective associations between habitual diet quality and the prevalence of risk for depression. These associations have been consistently observed in adults, adolescents and children across a multitude of different countries and cultures.[24] A recent systematic review and meta-analysis, including results from 13 observational studies, concluded that a healthy diet is significantly associated with a reduced odds for depression [odds ratio (OR) 0.84; 95% confidence interval (95% CI) 0.76–0.92; P < 0.001].[25] Similarly, a meta-analysis of 22 studies investigating the protective effects of adherence to a Mediterranean-style diet on brain diseases demonstrated that higher adherence was associated with a reduced risk for depression (relative risk 0.68, 95% CI 0.54–0.86), as well as cognitive decline.[7] Moreover, increased consumption of unhealthy, sugar and fat-rich foods is related to an increased risk of psychological symptomatology in children and adolescents.[8] Of particular note are results from two new, large, cohort studies suggesting an independent role for early life nutritional exposures in influencing the mental health of offspring.[26,27] These observational studies are supported by two recent trials that indicate the efficacy of dietary improvement as a strategy for the prevention of depression.[28,29] Although this field is still evolving, treatment trials are currently underway.[30] The focus is now turning to the explication of biological pathways that may mediate this now-established association, foremost being the gut microbiota.