School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China.
School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, China and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, China.
Food Funct. 2019 Jul 17;10(7):4046-4061. doi: 10.1039/c9fo00213h.
Gallic acid (GA), a plant phenol found in fruits and vegetables, has been recently reported to attenuate ulcerative colitis (UC). However, the mechanism of GA in UC remains unknown. In this study, we investigated the therapeutic effects of GA on UC from the perspective of gut microbiota and supervised the metabolic alterations in vivo with 1H NMR-based metabolomics, which can provide a holistic view to understand the functions of GA in UC. Rats with dextra sulfate sodium (DSS)-induced colitis were rectally administrated with GA (6 mg kg-1) for 8 consecutive days. 16S gene sequencing was performed on feces samples to obtain bacterial community information. Urine and feces samples were analyzed with 1H NMR spectroscopy, and short chain fatty acids (SCFAs) in feces and colon contents were detected with gas chromatography. Our results showed that UC syndromes in the GA group were significantly attenuated. The microbial alterations in the DSS group were characterized by a decrease of probiotic bacteria, such as Lactobacillaceae and Prevotellaceae, and an increase of some pathogenic species, mainly in the Firmicutes and Proteobacteria phyla. GA treatment could modulate the microbiota composition towards a similar proportion to the control group. Metabolic data further revealed that the GA-induced metabolic changes focus on increasing carbohydrate metabolism (gluco-related metabolism) and bile acid (BA) metabolism and decreasing amino acid metabolism, which also provides evidence for alteration of the microbiota because these feces metabolites are by-products of interactions between the host and the microbiota. These findings demonstrate GA-induced alterations in metabolic and bacterial profiles in DSS-colitis, providing new insight into the attenuation of GA in UC.
没食子酸（GA）是一种存在于水果和蔬菜中的植物酚，最近有报道称其可减轻溃疡性结肠炎（UC）。然而，GA 在 UC 中的作用机制尚不清楚。在这项研究中，我们从肠道微生物群的角度研究了 GA 对 UC 的治疗作用，并通过基于 1H NMR 的代谢组学对体内代谢变化进行了监测，这可以提供一种整体的视角来理解 GA 在 UC 中的作用。用葡聚糖硫酸钠（DSS）诱导结肠炎的大鼠通过直肠给予 GA（6mg/kg）连续 8 天。对粪便样本进行 16S 基因测序以获取细菌群落信息。用 1H NMR 光谱法分析尿液和粪便样本，并通过气相色谱法检测粪便和结肠内容物中的短链脂肪酸（SCFAs）。结果显示，GA 组的 UC 症状明显减轻。DSS 组的微生物变化特征是益生菌减少，如乳杆菌科和普雷沃氏菌科，而一些致病物种增加，主要在厚壁菌门和变形菌门。GA 处理可以使微生物群落组成向类似于对照组的方向调节。代谢数据进一步表明，GA 诱导的代谢变化集中在增加碳水化合物代谢（与葡萄糖相关的代谢）和胆汁酸（BA）代谢，减少氨基酸代谢，这也为微生物的变化提供了证据，因为这些粪便代谢物是宿主与微生物相互作用的副产物。这些发现表明 GA 诱导的 DSS-结肠炎代谢和细菌谱的改变，为 GA 减轻 UC 提供了新的见解。
