Vitamins formed by microorganisms in fermented foods: effects on human vitamin status-a systematic narrative review.
Level 2 - randomized trial
Systematic review synthesizing both interventional and observational human studies.
PubMed 41127087 · doi:10.3389/fnut.2025.1653666
What was done
A systematic literature search covering 1970 to 2024 was conducted following EFSA and COST Action PIMENTO protocols. The authors reviewed interventional and observational human studies evaluating the effect of consuming fermented foods rich in microbially synthesized vitamins on human vitamin biomarkers.
What was found
The abstract reports no numerical values, effect sizes, or participant counts. Microorganisms including Bacillus subtilis, Propionibacterium freudenreichii, and certain lactic acid bacteria increased levels of vitamins K2, B2, B9, and B12 in fermented foods. In humans, vitamin K2 status improved after consuming natto across several studies and Jarlsberg cheese in one study, while folate bioavailability improved following Camembert cheese consumption. Evidence was limited or inconsistent for vitamins B1, B2, B3, B5, B6, and B12, and absent for other vitamins.
Why it matters
This review clarifies the extent to which microbial vitamin production in fermented foods translates into measurable human nutritional benefits, confirming specific effects for vitamin K2 and folate while highlighting major gaps for other vitamins.
Limits
The abstract omits study counts, participant numbers, and meta-analytic pooling. Findings are limited by substantial variability in food matrices, fermentation types, microbial strains, vitamer forms, gut microbiota interactions, and a general lack of well-controlled large-scale clinical trials.
Cited by
- supports Fermenting bacteria in fermented foods produce and secrete B vitamins.