The effect of colon-delivered vitamin B2 on the gut microbiota and related health biomarkers in healthy older adults: A randomized, double-blinded, placebo-controlled parallel-arm clinical study
Objective
The primary objective of this study was to investigate the effect of colondelivered vitamin B2 on microbial composition and function in healthy elderly participants.
Method
In this placebo-controlled, parallel-arm, double-blinded study, 348 participants (aged 50–70 years) were recruited and randomized to receive one capsule per day containing either 1.4 mg, 10 mg, or 75 mg of colon delivered vitamin B2, or placebo (microcrystalline cellulose) for 12 weeks. Fecal samples were collected at baseline, 4 weeks, and 12 weeks to analyze the microbiome and its metabolites. Blood samples were also taken at baseline and week 12 to assess safety and secondary endpoints, including hs-CRP, haematology, blood lipids and vitamin B2 levels. The study protocol was reviewed and approved by the Clinical Research Ethics Committee of the Cork Teaching Hospitals, Cork (ECM 4 (JJ) 22 Feb 2022) and registered at clinicaltrials.gov (ID: NCT05803811).
Results
Colon-delivered vitamin B2 at 10 mg significantly (padj=0.014) increased fecal microbial diversity at week 12 when compared to baseline, with notable shifts in the abundance of several microbial taxa such as Blautia and Coprococcus. Additionally, 75 mg dose significantly raised fecal butyrate levels at week 4 when compared to baseline (padj=0.024) and placebo (padj=0.034). All tested doses improved systemic vitamin B2 status, with a significant increase in the 75 mg group at week 12 when compared to baseline (padj=0.008) and placebo (padj=0.003). There were no reported safety concerns (hs-CRP, haematology, blood lipids) for any dose of colon delivered vitamin B2.
Conclusion
In conclusion, colon-delivered vitamin B2 beneficially modulates the gut microbiome by enhancing microbial diversity, altering the abundance of specific microbial taxa, raising butyrate levels and improving systemic vitamin B2 status. Notably, the administration of colon-delivered vitamin B2 was well-tolerated, with no safety concerns, making it a novel and promising approach for supporting micronutrient cross-feeding of microbial communities.
Clinical Trial Registration - The study protocol was reviewed and approved by the Clinical Research Ethics Committee of the Cork Teaching Hospitals, Cork (ECM 4 (JJ) 22 Feb 2022) and registered at clinicaltrials.gov (ID: NCT05803811).