Moringa oleifera polysaccharides regulates caecal microbiota and small intestinal metabolic profile in C57BL/6 mice

This study investigated the effects of Moringa oleifera polysaccharides (MOP) on the serum indexes, small intestinal morphology, small intestinal metabolic profile, and caecal microbiota of mice. A new type of polysaccharides with 104,031 Da molecular weight and triple helix structure was isolated from M. oleifera leaves for in vivo experiment. Forty male SPF C57BL/6 mice aged 4 weeks were average divided into four groups randomly according to the MOP gavaged daily (0, 20, 40 and 60 mg/kg body weight MOP). After a 7-day preliminary trial period and a 28-day official trial period, the mice were slaughtered. Results showed that MOP reduced glucose, total cholesterol, and malondialdehyde. It also improved superoxide dismutase and catalase in serum (P < 0.05). For small intestinal morphology, MOP improved the villi length and crypt depth in both ileum and jejunum (P < 0.05); the ratio of villi length to crypt depth in jejunum increased (P < 0.05). MOP could cause the increase of beneficial bacteria and the decrease of harmful bacteria in caecum, further affecting the function of microbiota. In addition, MOP regulated 114 metabolites enriched in the pathway related to the synthesis and metabolism of micromolecules. In sum, MOP exerted positive effects on the serum indexes and intestinal health of mice.