In vitro gastrointestinal digestion and fecal fermentation behaviors of pectin from feijoa (Acca sellowiana) peel and its impact on gut microbiota

This study investigated the digestion and fermentation characteristics of pectin from feijoa peel (FPP) and its effect on gut microbiota via in vitro simulated digestion and fecal fermentation. The gastrointestinal results showed that the molecular weight (Mw) of FPP kept stable with small production of reducing sugar and free monosaccharides, indicating that FPP was basically not degraded during digestion. However, during the fecal fermentation, the Mw of FPP significantly decreased with the release of free monosaccharides, which were further utilized by gut microbiota. The content of reducing sugar showed a trend of increasing at first and then decreasing. The production of gases and short-chain fatty acids (SCFAs) increased with the utilization of FPP, along with the pH decrease in fecal culture. Meanwhile, FPP regulated the composition of gut microbiota by suppressing enteropathogenic bacteria (genera Escherichia-Shigella and Fusobacterium) and promoting beneficial bacteria (genera Lactiplantibacillus and Bifidobacterium). Significantly positive correlation was found between SCFAs and bacteria including Lactiplantibacillus and Bifidobacterium. These results suggested that FPP had potential prebiotic functions to promote human intestinal health.