Association between soft drink consumption and depression mediated by gut microbiome: a perspective.

This perspective synthesises current evidence on the association between soft drink consumption and depression, with emphasis on the gut microbiome as a potential mediating mechanism. PubMed, Scopus, and Google Scholar were searched using the following terms: 'soft drinks', 'sugar-sweetened beverages', 'carbonated beverages', 'soda', 'depression', 'depressive symptoms', 'mental health', 'gut microbiome', 'microbiota', and 'gut-brain axis'. Peer-reviewed original articles published in English between January 2000 and October 2025 were included if they involved human participants of any age (sample size ≥50 for observational studies), assessed soft drink or sugar-sweetened beverage consumption, and measured depression diagnosis, depressive symptoms, or depression severity. Associations between soft drink consumption and increased depression risk were consistently shown across multiple study designs and populations. Evidence for artificially sweetened beverages was less consistent and suggested potentially distinct, non-sugar-related pathways. A multicentre cohort study of 932 participants revealed that soft drink consumption predicted the major depressive disorder diagnosis (odds ratio = 1.081), with stronger effects in women (odds ratio = 1.167). Eggerthella partially mediated the soft drink-depression association, explaining approximately 4% of the association. Soft drink consumption is associated with increased depression risk through multiple biological pathways involving inflammation, metabolic dysregulation, and gut microbiome alterations. Modest effect sizes suggest the involvement of multiple interconnected mechanisms. Public health interventions to limit sugar-sweetened beverage consumption are recommended to improve physical and mental health. Healthcare providers should consider dietary assessment and counselling as part of depression prevention and treatment strategies.