Nutraceutical formulations combining Limosilactobacillus fermentum, quercetin, and or resveratrol with beneficial impacts on the abundance of intestinal bacterial populations, metabolite production, and antioxidant capacity during colonic fermentation.

This study evaluated the impacts of different nutraceutical formulations combining Limosilactobacillus fermentum 296 (∼10 log CFU/mL), quercetin (QUE, 160 mg), and or resveratrol (RES, 150 mg) on the relative abundance of various intestinal bacterial populations, production of microbial metabolites, and antioxidant capacity during 48 h of in vitro colonic fermentation. The nutraceutical formulations increased the relative abundance of Lactobacillus spp./Enterococcus spp. and Bifidobacterium spp. and decreased the relative abundance of Bacteroides spp./Prevotella spp., Clostridium histolyticum, and E. rectale/C. coccoides during the colonic fermentation. Medium with the formulation containing L. fermentum, QUE, and RES had the highest prebiotic indexes, indicating synergistic or additive interaction between QUE and RES to modulate the intestinal microbiota. The nutraceutical formulations increased the production of bioactive metabolites and antioxidant capacity in the colonic fermentation media. The results indicate the capability of the tested nutraceutical formulations to beneficially modulate the composition and metabolite production of human intestinal microbiota and increase the antioxidant capacity in the intestinal environment.