Pilot RCT Finds Blueberry Powder Alters Select Gut Microbiome Enzyme Genes Without Significant Mood Benefit
Small pilot RCT detected blueberry-linked shifts in gut enzyme commissions without statistically significant mood effects. Evidence remains preliminary; larger trials with clinical endpoints are required before dietary recommendations can be updated.
Next steps require a fully powered multicenter RCT with at least 120 participants, longer follow-up, and stratification by baseline microbiome diversity to test whether enzyme changes mediate symptom improvement. Funding agencies should prioritize trials that include both metagenomic and metabolomic readouts alongside clinician-rated depression scales.
Millar et al.: A follow-up RCT with n≥120 will detect a ≥3-point between-group difference on the Geriatric Depression Scale at 6 months (p<0.05) if the enzyme changes are causal.
Sources (2)
- [1]Primary Source(https://doi.org/10.1016/j.jnha.2026.100958)
- [2]Supporting Source(https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2801234)