辣木叶对低纤维膳食致便秘大鼠肠道菌群的调控研究

Regulatory Effect of Moringa oleifera Leave on Intestinal Flora in Rats with Constipation Induced by a Low-Fiber Diet

目的:探究辣木叶对低纤维膳食所致大鼠便秘的肠道菌群影响。方法:SD大鼠30只,随机分为正常对照组、模型对照组、比沙可啶1.8 mg/kg组、辣木叶0.63、2.5 g/kg组。大鼠低纤维饲料造模28 d后连续给药7 d,记录辣木叶提取物对大鼠排便、胃排空率及小肠推进率的影响;收集大鼠粪便与结肠内容物,采用Illumina Miseq测序平台进行16srDNA基因测序。结果:与正常对照组比较,模型对照组粪便粒数显著减少;与模型对照组比较,辣木叶0.63 g/kg可明显改善低纤维膳食诱导的便秘大鼠粪便粒数(P<0.05);模型对照组大鼠拟杆菌属(Bacteroidetes)水平降低,辣木叶2.5 g/kg组水平升高;模型对照组的变形菌门(Proteobacteria)和放线菌门(Actinobacteria)水平升高。LEfSe分析发现辣木叶组的优势菌群为毛螺旋菌科、瘤胃菌科Ruminococcaceae、等,预测辣木叶可通过参与氨基酸的生物合成、ABC转运蛋白、碳代谢、群体效应和双信号传导等通路,调节肠道菌群的稳定。结论:辣木叶可改善低纤维膳食诱导的大鼠便秘,增加肠道微生物多样性并维持肠道菌群稳态,其可能是辣木叶在印度阿育吠陀医学记载的Virechana作用的机制之一。

Objective:To investigate the effect of Moringa oleifera leaves(MOL) on intestinal flora in constipation rats reduced by a low-fiber diet. Methods:Thirty SD rats were randomly divided into a normal control group, a model control group, a bisacodyl group(1.8 mg/kg),and MOL groups(0.63 g/kg and 2.5 g/kg). After modeling with a low-fiber diet for 28 days, the rats were orally administered MOL for 7 days. The effects of MOL extract on fecal excretion, gastric emptying rate, and small intestine propulsion rate in rats were recorded. Fecal samples and colonic contents were collected, and 16S rDNA gene sequencing was performed using the Illumina MiSeq platform. Results:Compared with normal control group, model group significantly reduced the fecal pellets in rats, compared with model group, MOL(0.63 g/kg) significantly improved the fecal pellets in rats with low-fiber diet-induced constipation(P<0.05). The level of Bacteroides was reduced in the model control group, while it was increased in the MOL group at 2.5 g/kg. The levels of Proteobacteria and Actinobacteria were increased in the model control group. LEfSe analysis revealed that dominant intestinal flora in the MOL groups included Lachnospiraceae and Ruminococcaceae. It was predicted that MOL could regulate the stability of intestinal flora by participating in amino acid biosynthesis, ABC transporter protein, carbon metabolism, population effect, and dual signaling pathways. Conclusion:MOL can improve constipation induced by a low-fiber diet in rats, increase intestinal microbial diversity, and maintain intestinal microflora homeostasis. This may be one of the mechanisms underlying the "Virechana" effect described in Ayurvedic medicine for MOL.