黄精提取物的体外模拟消化特性及对肠道菌群的影响

Simulated Digestion of Polygonatum sibiricum Extract in Vitro and Its Effect on Intestinal Flora

目的:采用体外模拟消化结合16S rDNA高通量测序技术探究黄精提取物活性成分含量的变化及对肠道菌群调节作用。方法:通过加热回流法制备黄精提取物,测定体外模拟消化前后黄精提取物中多糖、皂苷和黄酮的含量,并考察其对α-葡萄糖苷酶的抑制能力。基于16S rDNA高通量测序分析黄精提取物对肠道菌群的影响。结果:黄精提取物含有多糖、皂苷、黄酮的含量分别为0.4732、0.0632和0.0754 mg/mL。经体外模拟消化后,多糖、皂苷、黄酮的含量均显著降低(P<0.05),且加入消化酶组显著低于未加入消化酶组(P<0.05)。另外,消化后黄精提取物对α-葡萄糖苷酶抑制能力显著降低(P<0.05)。随着体外发酵时间的增加,黄精提取物处理组粪便发酵的pH从初始的6.85下降到4.13,48 h后发酵液呈弱酸性。肠道菌群分析表明,黄精提取物能改变肠道菌群结构,尤其在门、属水平上具有一定程度的改善作用。黄精提取物可增加厚壁菌门(Firmicutes)丰度,降低变形菌门(Proteobacteria)的丰度,增加双歧杆菌属(Bifidobacterium)相对丰度,并且显著降低纺锤链杆菌属(Fusicatenibacter)相对丰度(P<0.05)。结论:黄精提取物经体外模拟消化后多糖、皂苷和黄酮的含量显著降低(P<0.05),对α-葡萄糖苷酶的抑制作用降低,可改变肠道微生物群落结构,对肠道菌群具有一定的调节作用。本研究可为黄精精深加工及调节肠道菌群方面提供理论参考。

Objective:To explore the changes of active components in Polygonatum sibiricum extract and its regulation on intestinal flora by in vitro simulated digestion combined with 16S rDNA high-throughput sequencing technology.Methods:P.sibiricum extract was prepared by heating reflux method.The contents of polysaccharides,saponins and flavonoids in P.sibiricum extract before and after simulated digestion in vitro were determined,and its inhibitory ability onα-glucosidase was investigated.The effect of P.sibiricum extract on intestinal flora was analyzed based on 16S rDNA high-throughput sequencing.Results:The P.sibiricum extract contained polysaccharides,saponins and flavonoids,and the contents were 0.4732,0.0632 and 0.0754 mg/mL,respectively.After in vitro simulated digestion,the contents of polysaccharides,saponins and flavonoids were significantly reduced(P<0.05),and the addition of digestive enzymes was significantly lower than that of the group without digestive enzymes(P<0.05).In addition,the inhibitory ability of P.sibiricum extract onα-glucosidase was significantly reduced after digestion(P<0.05).With the increase of in vitro fermentation time,the pH of the fecal fermentation broth in the P.sibiricum extract treatment group decreased from the initial 6.85 to 4.13,and the fermentation broth was weakly acidic after 48 h.The analysis of intestinal flora showed that P.sibiricum extract could change the structure of intestinal flora,especially at the level of phylum and genus.P.sibiricum extract increased the abundance of Firmicutes,decreased the abundance of Proteobacteria,increased the relative abundance of Bifidobacterium,and significantly decreased the relative abundance of Fusicatenibacter(P<0.05).Conclusion:The contents of polysaccharides,saponins and flavonoids in P.sibiricum extract were significantly decreased after in vitro simulated digestion(P<0.05),and the inhibitory effect onα-glucosidase was decreased.It could change the structure of intestinal microbial community and had a certain regulatory effect on intestinal flora.This study can provide a theoretical reference for the deep processing of P.sibiricum and the targeted regulation of intestinal flora.