Table_7_Metagenomics and metabolomics analysis to investigate the effect of Shugan decoction on intestinal microbiota in irritable bowel syndrome rats.XLS

BackgroundThe effect of Shugan Decoction (SGD) on intestinal motility and visceral hypersensitivity in Water avoid stress (WAS)-induced diarrhea predominant irritable bowel syndrome (IBS-D) model rats has been confirmed. However, the mechanisms of its action involved in the treatment of IBS-D need to be further studied. Intestinal microbiota plays an important role in maintaining intestinal homeostasis and normal physiological function. Changes in the intestinal microbiota and its metabolites are thought to participate in the pathophysiological process of IBS.
AimThis study aimed to analyze the influence of SGD on intestinal microbiota and fecal metabolites in IBS-D rats by multiple omics techniques, including metagenomic sequencing and metabolomics.
MethodsWe measured the intestinal motility and visceral sensitivity of three groups of rats by fecal pellets output and colorectal distension (CRD) experiment. In addition, metagenome sequencing analysis was performed to explore the changes in the number and types of intestinal microbiota in IBS-D model rats after SGD treatment. Finally, we also used untargeted metabolomic sequencing to screen the metabolites and metabolic pathways closely related to the therapeutic effect of SGD.
ResultsWe found that compared with the rats in the control group, the fecal pellets output of the rats in the WAS group increased and the visceral sensitivity threshold was decreased (P < 0.05). Compared with the rats in the WAS group, the fecal pellets output of the SGD group was significantly decreased, and the visceral sensitivity threshold increased (P < 0.05). Besides, compared with the rats in the WAS group, the relative abundance of Bacteroidetes increased in SGD group, while that of Firmicutes decreased at the phylum level, and at the species level, the relative abundance of Bacteroides sp. CAG:714, Lactobacillus reuteri and Bacteroides Barnesiae in SGD group increased, but that of bacterium D42-87 decreased. In addition, compared with the WAS group, several metabolic pathways were significantly changed in SGD group, including Taurine and hypotaurine metabolism, Purine metabolism, Sulfur metabolism, ABC transporters, Arginine and proline metabolism and Bile secretion.
ConclusionSGD can regulate specific intestinal microbiota and some metabolic pathways, which may explain its effect of alleviating visceral hypersensitivity and abnormal intestinal motility in WAS-induced IBS-D rats.

背景：疏肝汤（Shugan Decoction, SGD）对水回避应激（Water avoid stress, WAS）诱导的腹泻型肠易激综合征（diarrhea predominant irritable bowel syndrome, IBS-D）模型大鼠的肠动力与内脏高敏感性的干预效应已得到证实，但其治疗IBS-D的具体作用机制仍有待进一步研究。肠道菌群在维持肠道稳态与正常生理功能中发挥重要作用，肠道菌群及其代谢产物的异常改变被认为参与了IBS的病理生理过程。
研究目的：本研究旨在通过宏基因组测序（metagenomic sequencing）与代谢组学（metabolomics）等多组学技术，分析疏肝汤（SGD）对IBS-D模型大鼠肠道菌群及粪便代谢物的影响。
研究方法：本研究通过粪便粒排出实验与结直肠扩张（colorectal distension, CRD）实验，评估三组大鼠的肠动力与内脏敏感性。此外，采用宏基因组测序分析，探究疏肝汤干预后IBS-D模型大鼠肠道菌群的数量与种类变化；同时，利用非靶向代谢组学测序技术，筛选与疏肝汤治疗效应密切相关的代谢物及代谢通路。
研究结果：与对照组大鼠相比，水回避应激组大鼠的粪便粒排出量升高，内脏敏感性阈值降低（P < 0.05）。与水回避应激组相比，疏肝汤组大鼠的粪便粒排出量显著降低，内脏敏感性阈值升高（P < 0.05）。在菌群门水平上，疏肝汤组大鼠的拟杆菌门（Bacteroidetes）相对丰度升高，厚壁菌门（Firmicutes）相对丰度降低；在种水平上，疏肝汤组大鼠的Bacteroides sp. CAG:714、罗伊乳杆菌（Lactobacillus reuteri）与Barnes类杆菌（Bacteroides Barnesiae）相对丰度升高，而bacterium D42-87相对丰度降低。此外，与水回避应激组相比，疏肝汤组大鼠的多条代谢通路发生显著改变，包括牛磺酸与次牛磺酸代谢、嘌呤代谢、硫代谢、ABC转运蛋白（ABC transporters）、精氨酸与脯氨酸代谢以及胆汁分泌。
研究结论：疏肝汤可调控特定肠道菌群及部分代谢通路，这或可阐释其改善水回避应激诱导的IBS-D模型大鼠内脏高敏感性与肠动力异常的作用机制。