Effects of a homogeneous polysaccharide from Sijunzi decoction on human intestinal microbes and short chain fatty acids in vitro
Effects of a homogeneous polysaccharide from Sijunzi decoction on human intestinal microbes and short chain fatty acids in vitro
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四君子汤同质多糖对体外人体肠道微生物和短链脂肪酸的影响
DOI：
10.1016/j.jep.2018.06.006
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发表时间：
2018-10-05
影响因子：
5.4
通讯作者：
Li, Xiaobo
中科院分区：
文献类型：
--
作者：
Gao, Beibei;Wang, Ruijun;Li, Xiaobo
民族药理学相关性：四君子汤是健脾益气的经典方剂。众所周知，它用于治疗表现为食欲不振、食物摄入减少和稀便的胃肠道功能障碍。多糖是四君子汤中含量最丰富的成分，也是其主要的有效成分。本研究的目的：本研究旨在通过研究从四君子汤中分离纯化的具有免疫增强活性的均质多糖S-3-1对人体肠道微生物和短链脂肪酸的影响，了解其免疫调节机制。将S-3-1与模拟胃液、肠液和人粪便微生物菌群单独和依次孵育。测定总多糖和还原糖的浓度，以鉴定独立和顺序孵育的S-3-1在三种体外发酵模型中的稳定性。采用气相色谱法（GC）测定人粪便中短链脂肪酸（SCFA）的含量。结果：S-3-1在3种体外发酵模型中均能被降解，且降解顺序依次为：16 S rRNA基因V3-V4区测序。S-3-1和孵育的S-3-1均能调节人肠道菌群中乳酸杆菌、片球菌、链球菌、拟杆菌、肠球菌、梭菌和多雷氏菌的丰度。S-3-1仅能调节副旋藻和颤螺旋藻的丰度，而受影响的植物群经S-3-1连续孵育后，变为丁酸单胞菌属、粪球菌属、小杆菌属、Sutterella、瘤胃球菌属和副拟杆菌属。与不影响SCFA含量的S-3-1相比，培养的S-3 -1可增加乙酸和总酸含量，这与其对肠球菌属、萨特雷氏菌属、丁酸单胞菌属和链球菌属丰度的影响有关。培养的S-3-1可调节的菌属较多，共13种，并可调节SCFA含量，影响免疫调节。与胃液和肠液一起孵育增强了S-3-1调节肠道植物群组成的能力，并降低了细菌对碳源的需求。本研究为多糖体外药理作用机制的研究提供了新的思路。
Ethnopharmacological relevance: Sijunzi decoction (SJZD) is a classic recipe in traditional Chinese medicine (TCM) to strengthen the spleen and replenish Qi. It is well known for treating disorders of gastrointestinal function manifested in poor appetite, reduced food intake and loose stools. Polysaccharide is the most abundant constituent and the major effective component in SJZD.Aim of the study: The present study aimed to understand the immunomodulatory mechanism of S-3-1, a homogeneous polysaccharide purified from SJZD with immune-enhancement activity, by investigating its effects on human intestinal microbes and short chain fatty acids.Materials and methods: S-3-1 was incubated with simulated gastric juice, intestinal juice, and human fecal microflora independently and sequentially. The concentrations of total polysaccharide and reducing sugar were measured to identify the stability of independently and sequentially incubated S-3-1 in three in vitro fermentation models. Gas chromatograph (GC) analysis was used to measure the short chain fatty acid (SCFA) contents in human fecal samples. The human gut microbiota composition was measured by 16S rRNA gene Illumina MiSeq sequencing (V3-V4 region).Results: S-3-1 was degraded in three in vitro fermentation models separately and sequentially. Both S-3-1 and incubated S-3-1 could regulate the abundances of Lactobacillus, Pediococcus, Streptococcus, Bacteroides, Enterococcus, Clostridium and Dorea in human intestinal microflora samples. Specifically, S-3-1 could only regulate the abundances of Paraprevotella and Oscillospira, while the influenced flora changed to Butyricimonas, Coprococcus, Dialister, Sutterella, Ruminococcus and Parabacteroides after sequential incubation of S-3-1. In contrast to S-3-1 showing no influence on the content of SCFA, incubated S-3-1 showed increased contents of acetic acid and total acid that were associated with its effects on the abundances of Enterococcus, Sutterella, Butyricimonas and Streptococcus.Conclusion: S-3-1 plays an immunomodulatory role by regulating the abundances of 9 intestinal bacteria genera. Incubated S-3-1 can regulate more bacteria genera, a total of 13 kinds, and can adjust the SCFA content to affect immunomodulation. Incubation with gastric and intestinal juices enhanced S-3-1's capability of modulating the intestinal flora composition and decreased the bacteria's need for a carbon source. This study could provide new insights for studies on the pharmacological mechanisms of polysaccharides in vitro.