Abstract:Nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) are two precursors of the redox coenzyme nicotinamide adenine dinucleotide (NAD). Due to their ability to effectively increase NAD levels without toxic side effects, they have garnered significant attention.Objective This study employed an integrated approach combining metabolomics and 16S rRNA gene sequencing to investigate and compare the effects of NMN or NR supplementation on growth performance, intestinal health, gut microbiota, and metabolites in mice.Methods Male C57 mice were randomly allocated into a control group and two experimental groups. The experimental groups received drinking water supplemented with NMN or NR via gavage. Non-targeted metabolomics analysis and 16S rRNA gene sequencing were conducted to systematically investigate the alterations in endogenous metabolites and gut microbiota composition. Furthermore, the expression levels of associated factors were quantified by PCR.Results Compared with the control group, supplementation with NMN or NR increased the richness and diversity and improved the composition of gut microbiota in mice, with NMN showing greater efficacy. Additionally, both NMN and NR supplementation significantly upregulated the expression levels of metabolites associated with anti-inflammatory and antioxidant activities. PCR results indicated that both NMN and NR suppressed the expression of pro-inflammatory cytokines. Furthermore, NMN supplementation significantly increased the number of goblet cells in the colon, thereby enhancing the intestinal barrier function.Conclusion Dietary supplementation with NMN or NR improves the gut microbiota composition in mice, elevates the levels of beneficial metabolites, and inhibits the expression of pro-inflammatory cytokines.
