Nicotinamide Riboside and NMN Boost NAD+ Through Microbiota Conversion: Preclinical Findings

Synopsis

Using NAD+ metabolomics in mice, this study found that nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) are not directly absorbed intact in large amounts. Instead, most orally administered NMN and NR are deamidated by gut microbiota and converted into nicotinic acid (NA), which is then used to make NAD+. Intravenous NMN and NR are also rapidly broken down into nicotinamide, secreted into bile, and again transformed into NA by gut microbes through enterohepatic circulation. The liver preferentially uses this microbiota-derived NA for NAD+ synthesis. These results show that NMN and NR mainly boost NAD+ indirectly via conversion to NA, revealing unexpected metabolic routes in vivo.

Journal

Science Advances