基于代谢组学研究马齿苋多糖对老年大鼠粪便代谢物的影响

研究马齿苋多糖（POP）对老年大鼠粪便代谢物的影响,为其在老年功能食品开发利用上提供理论依据。实验中20只SD老年大鼠（21月龄）随机分为2组,每组10只。对照组大鼠饲喂实验鼠维持颗粒料,马齿苋多糖补充组大鼠饲喂混合实验鼠维持颗粒料（添加1.0% POP）,自由摄食和饮水,持续15 w。实验结束后,用自动生化仪检测血清中生化指标,苏木精-伊红染色观察结肠的组织形态变化。气相色谱仪-质谱联用仪分析结肠内容物中短链脂肪酸含量;液相色谱-质谱联用仪检测粪便样本,鉴定差异代谢物,分析代谢通路。结果显示：（1）补充摄入马齿苋多糖可显著性降低老年大鼠血清中总胆固醇、甘油三酯、低密度脂蛋白胆固醇和直接胆红素水平。（2）马齿苋多糖组老年大鼠结肠形态规则,结构更清晰和更完整,结肠内容物中丙酸和己酸的含量显著性增加。（3）两组粪便中共筛选到10个分离贡献性大的差异性代谢物,获得有显著性差异的代谢通路为亚油酸代谢、花生四烯酸代谢、初级胆汁酸生物合成、5-羟色胺能突触、嘧啶代谢、组氨酸代谢、缬氨酸/亮氨酸/异亮氨酸的生物合成。（4）甘油三酯、低密度脂蛋白胆固醇和肌酐水平分别与牛磺鹅去氧胆酸、11-羟基-12,13-环氧-9-十八碳烯酸、六亚甲基四胺和7α-羟基-3-氧代-4-胆甾醇酸酯存在相关性。 马齿苋多糖可能通过影响粪便中代谢物来改善老年大鼠血脂水平和直接胆红素含量,进而有益老年大鼠机体健康。

METABOLOMIC STUDY ON EFFECTS OF PORTULACA OLERACEA L. POLYSACCHARIDES ON FECAL METABOLITES IN AGED RATS

To investigate the effects of Portulaca oleracea polysaccharides (POP) on fecal metabolites in aged rats, and provide a theoretical basis for its development and utilization of functional foods for the elderly, twenty aged Sprague-Dawley (SD) rats (21 months old) were randomly divided into two groups with ten rats in each group. Control group (Con) rats were fed with laboratory maintenance pellets, and supplementary feeding group (POP) rats were fed with mixed laboratory maintenance pellets (plus 1.0% POP) with free feeding and drinking for 15 weeks consecutively. Then, the automatic biochemical instrument and hematoxylin-eosin staining respectively were used to detect the biochemical indicators in serum, and observe the changes of the tissue morphology of the colon. The levels of short chain fatty acids (SCFAs) in colon contents were analyzed using GC-MS. LC-MS technology was used to detect the feces samples, identify the differential metabolites, and analyze the metabolic pathways. The results showed as follows: (1) Supplements of P. oleracea polysaccharides can significantly reduce total cholesterol, triglycerides, low-density lipoprotein cholesterol, and direct bilirubin levels in the serum of aged rats. (2) Regular morphology and clearer and more intact structures of the colons, and the significantly increased levels of propionic acid and Hexanoic acid in the colon contents were observed in the aged rats treated with POP. (3) A total of 10 differential metabolites with high separation contribution were screened in feces of the two groups, and significant differences in metabolic pathways were obtained, including linoleic acid metabolism, arachidonic acid metabolism, primary bile acid biosynthesis, serotonergic synapse, pyrimidine metabolism, histidine metabolism, and valise, leucine and isoleucine biosynthesis. (4) Triglycerides, low-density lipoprotein cholesterol, and creatinine levels in the serum are associated with 11-hydroperoxy-12,13-epoxy-9-octadecenoic acid, methenamine, taurochenodeoxycholic acid, and 7alpha-hydroxy-3-oxo-4-cholestenoate, respectively. The results indicate that P. oleracea polysaccharides may alleviate the blood lipid levels and direct bilirubin levels in aged rats by affecting metabolites in feces, thereby benefiting the health of the elderly body.