A meta-analysis of 19 studies with over 1400 adults with mild-to-moderate depression found that the use of probiotics and prebiotics, alone or in combination, significantly reduced the symptoms of depression and anxiety compared with nonuse. The study assessed depression and anxiety scores, revealing a standardized mean difference (SMD) of -1.8 for depression and -1.6 for anxiety. Subgroup analyses for depression showed variations on the basis of nationality, intervention duration, disease severity, and body mass index, while those for anxiety showed variations on the basis of nationality, age, assessment tool, and number of strains. Despite some concerns about bias in six studies, the findings suggest that these substances could complement standard treatments.
The Takeaway: Probiotics and prebiotics, alone or in combination, may enhance mental health treatment outcomes among patients with depression.
Cited from Medscape 6/23/25