In vitro digestibility and prebiotic activities of a bioactive polysaccharide from Moringa oleifera leaves

In this study, the digestion and fermentation properties of a bioactive polysaccharide (MOP-2) purified from Moringa oleifera leaves and its impact on the human colonic microbiota were determined using simulated saliva-gastrointestinal digestion and human fecal fermentation models in vitro. The results showed that the simulated saliva and gastric juices had no effect on the average molecular weight (MW) of MOP-2. The MW of MOP-2 slightly decreased from 155.29 to 145.02 kDa during intestinal digestion, and the reducing sugar content increased from 0.159 to 0.234 mg/ml, indicating that MOP-2 was partially degraded during intestinal digestion. During fermentation, MOP-2 was largely used by human fecal inoculums. Notably, MOP-2 could significantly regulate the structure of the microbial community by improving the relative abundances of some beneficial gut microbiota, such as Phascolarctobacterium, Coprococcus, Roseburia, and Bacteroides. Additionally, after fermentation for 48 hr, MOP-2 could significantly improve the production of short-chain fatty acids, especially n-butyric acid, acetic acid, propionic acid, and n-valeric acid. These results suggested that MOP-2 could potentially be a gut microbiota manipulator aimed at promoting gut health. PRACTICAL APPLICATIONS: Gut microbial community is an important part of the human intestinal environment. The health of gut microbiota is closely associated with host heath. This work reported that a polysaccharide (MOP-2) purified from Moringa oleifera leaves could modulate the microbial structure by improving the relative abundances of some beneficial gut microbiota, which provided useful information for the application of MOP-2 as a prebiotic additive in food industry.