苹果幼果果粉对体外模拟人体结肠微生物群的影响

Effects of Young Apple Powder on Simulated Human Colonic Microbiota in vitro

以苹果幼果为原料,采用真空冷冻干燥技术制备苹果幼果果粉(YAP),测定多酚和膳食纤维等主要成分含量,通过三阶段连续发酵系统模拟结肠发酵,并结合16S rRNA高通量测序和G C-MS分析,探究苹果幼果果粉对健康和肥胖志愿者结肠微生物群组成及短链脂肪酸的影响。结果表明,YAP中含有丰富的膳食纤维[(417.50±0.40)mg/g]和多酚类物质[(57.10±0.03)mg/g]。YAP使健康和肥胖志愿者的结肠反应器中菌群组成发生变化,其中Alpha多样性没有显著变化,而Beta多样性存在显著变化。低剂量YAP对结肠中不同细菌群的相对丰度有显著影响。在健康组中,YAP显著增加了拟杆菌门(Bacteroidota)的相对丰度,降低了变形菌门(Proteobacteria)的相对丰度;在肥胖组中,YAP显著增加了放线菌门(Actinobacteriota)的相对丰度。YAP对2个实验组属水平结肠微生物均有调节作用,使其相对丰度在7 d发酵周期内达到稳定值。此外,YAP促进了产短链脂肪酸菌的生成,增加了健康和肥胖志愿者结肠中的总短链脂肪酸浓度,短链脂肪酸中乙酸浓度最高。低剂量YAP显著增加了结肠样本中戊酸、丁酸和己酸的浓度(P<0.05)。体外模拟结肠发酵的结果表明,富含多酚和膳食纤维的YAP可显著调节健康和肥胖志愿者的结肠微生物群组成和短链脂肪酸含量,研究旨在为肠道菌群饮食调控提供新的思路和理论依据。

Using young apple fruits as raw materials,young apple powder(YAP)was prepared by vacuum freeze-drying technology,and the content of major components including polyphenols and dietary fiber was determined.A three-stage continuous fermentation system was used to simulate colonic fermentation,and combined with high-throughput 16S rRNA high-throughput sequencing and G C-MS analysis,the effects of YAP on the composition of colon microbiota and short-chain fatty acids in healthy and obese volunteers were explored.The results showed that YAP was rich in dietary fiber[(417.50±0.40)mg/g]and total polyphenolic substances[(57.10±0.03)mg/g].YAP altered the microbiota composition in colonic reactors of healthy and obese volunteers,with no significant changes in Alpha diversity but significant differences in Beta diversity.Low-dose YAP had a significant effect on the relative abundance of different bacterial groups in the colon.YAP significantly increased the relative abundance of Bacteroidota and decreased the relative abundance of Proteobacteria in the healthy group.In the obese group,YAP significantly increased the relative abundance of Actinobacteriota.Within a 7 d fermentation period,YAP had a regulatory effect on both experimental groups of genus-level colonic microbiota,resulting in their relative abundance reaching a stable value.YAP promoted the production of bacteria which could produce short-chain fatty acids and increased the total content of short-chain fatty acids in the colon of healthy and obese volunteers,with the highest content of acetic acid in short-chain fatty acids.Low-dose YAP significantly increased the concentration of valeric acid,butyric acid and caproic acid in colon samples(P<0.05).The results of simulated colonic fermentation in vitro showed that YAP rich in polyphenol-dietary fiber could significantly regulate the composition of colon microbiota and short-chain fatty acids in healthy and obese volunteers.This study aimed to provide new ideas and theoretical basis for dietary regulation of gut microbiota.