AUG 21, 2026 · JOURNAL ARTICLE
High dietary B12 is associated with reduced gut microbial B12 biosynthesis capacity and lower fecal short-chain fatty acids in healthy United States adults.
Gut Microbes
Observational cross-sectional study in healthy adults showing associations between dietary B12 and microbial function via metagenomic analysis, but lacking intervention design, clinical outcomes, or causal inference; findings require confirmation in prospective or interventional studies.
Reported
Sample size277
Dietary B12 intake range2.4 to 1062 µg/day
B12 intake threshold for stratifi…8.51 µg/day