Effects of Dietary Fiber Compounds on Characteristic Human Flora and Metabolites Mediated by the Longevity Dietary Pattern Analyzed by In Vitro Fermentation

The purpose of this study was to investigate the effects of different dietary fiber compounds (DFCs) on characteristic human flora and their metabolites mediated by the longevity dietary pattern analyzed by in vitro fermentation. The results show that DFC1 (cereal fiber) increased the level of Lactobacillus (p < 0.05), DFC2 (fruit and vegetable and cereal fiber) promoted the growth of Lactobacillus and Bifidobacterium more significantly than DFC3 (fruit and vegetable fiber) (p < 0.01), and all three DFCs decreased the level of Escherichia coli (p < 0.05). The metabolomic analysis showed that there was variability in the metabolites and the metabolic pathways of different DFCs. The redundancy analysis revealed that the fiber content was positively correlated with Lactobacillus, Bifidobacterium, Bacteroides, acetic acid, butyric acid, propionic acid, lactic acid, and betaine, and negatively correlated with Escherichia coli, succinic acid, alanine, choline, aspartic acid, and α-glucose. Overall, this study found that different DFCs have different positive correlations on characteristic human flora and metabolites, and DFC2 is more favorable to the proliferation of the intestinal beneficial genera Lactobacillus and Bifidobacterium after in vitro fermentation, having a probiotic role in glucose, amino acid, and lipid metabolisms. This study may provide a theoretical reference for the search of optimal dietary fiber combination strategies mediated by longevity dietary pattern.