Fig. 2: NR and Nam metabolism during ex vivo human faecal fermentation experiments and its impact on fermentation parameters.
a–c, The faecal-derived individual microbiome from six healthy adult donors was exposed for 48 h to NR (blue) or Nam (orange) and compared to an NSC (grey). a, Extracellular NAD+ metabolome concentrations are expressed in µM. The significance of the treatment effect is indicated (two-sided linear mixed-effects model). b, Impact of NR (blue) or Nam (orange) on gas production, total SCFAs and pH compared to NSC (grey). The significance of the treatment effect is indicated (two-sided linear mixed-effects model). c, Impact of NR or Nam on total bacterial cell counts (one-way ANOVA) and individually induced changes in E. aldensis (one-sample t test) in samples collected after 48 h of simulated colonic incubations. Significant differences between the treatments and NSC are indicated. d, Impact of NR on key fermentation parameters and extracellular NA 24 h after its addition to fermenting microbiota derived from healthy adults (n = 6), healthy older individuals (n = 10) or individuals with Crohn’s disease (CD; n = 10). Statistical differences between the treatments are indicated (two-way ANOVA). Data in a–d are expressed as mean +/− s.d. (a,b) or as boxes ranging from the upper to the lower quartile with the median indicated and the error bars representing the minimum and maximum values. 0.05 < $P < 0.1; 0.01 < *P < 0.05; 0.001 < **P < 0.01; ***P < 0.001; NS, not significant.
