DataSheet1_Antidepressant Shugan Jieyu Capsule Alters Gut Microbiota and Intestinal Microbiome Function in Rats With Chronic Unpredictable Mild Stress -Induced Depression.docx

Shugan Jieyu Capsule (SG) has been widely used in China to treat mild to moderate depression. Hypericum perforatum L. (St John’s Wort, SJW) is the main ingredient of SG and has been used as herbal medicine to treat depression in western countries. However, it is known that SJW has low bioavailability and does not easily get through the blood-brain barrier. Therefore, how SG plays an antidepressant effect in the central nervous system (CNS) remains an urgent problem to be solved. Mounting research has described the relationship between antidepressants and intestinal microbiota to illuminate antidepressive mechanisms in the CNS. We aimed to investigate the effects of therapy with SG on the function of gut microbiota and intestinal microbiota in rats with chronic unpredictable mild stress (CUMS)-induced depression. The psychophysiological state and the hypothalamic-pituitary-adrenal axis function of rats are evaluated through behavioral experiments, corticosterone levels, serotonin levels, and adrenal index measurements. 16S rDNA amplicon sequencing is used to test the changes in gut microbiota and make functional predictions of genes. With treatment of SG, the depression-like behaviors of CUMS-induced rats were reversed; the corticosterone levels and the adrenal index decreased significantly; the level of serotonin increased significantly; and the alpha and beta diversity analysis of microbiota showed an increase in the richness and uniformity of the flora were increased. SG regulated the relative abundance of Actinobacteria, Erysipelotrichaceae, Bifidobacteriaceae, Atopobiaceae, Dubosiella, and Bifidobacterium; Linear discriminant analysis effect size analysis demonstrated that Lactobacillaceae (family level), Lactobacillus (genus level), Lactobacillales (order level), Bacilli (class level), and Lactobacillus-reuteri (species level) were biomarkers in the SG group samples, and also likely to modulate metabolic pathways, such as those involved in carbohydrate metabolism, amino acid metabolism, and signal transduction. These data clearly illustrated the effect of SG on gut microbiome, thus laying the foundation for uncovering more insights on the therapeutic function of the traditional Chinese antidepressants. The potential of SG on mechanisms of antidepression to alter gut microbiota and intestinal microbiome function exposed to CUMS can be explored.

舒肝解郁胶囊（Shugan Jieyu Capsule，SG）目前已在国内广泛用于轻中度抑郁症的治疗。贯叶连翘（Hypericum perforatum L.，又名圣约翰草，SJW）是该胶囊的主要活性成分，在西方国家亦被用作抗抑郁草药。然而，现有研究表明圣约翰草生物利用度较低，且难以透过血脑屏障（blood-brain barrier）。因此，舒肝解郁胶囊如何在中枢神经系统（central nervous system，CNS）中发挥抗抑郁作用，仍是亟待解决的科学问题。
越来越多的研究聚焦于抗抑郁药物与肠道菌群的关联，以阐明其在中枢神经系统中的抗抑郁机制。本研究旨在探讨舒肝解郁胶囊干预对慢性不可预见性温和应激（chronic unpredictable mild stress，CUMS）诱导的抑郁模型大鼠肠道菌群结构与功能的影响。
研究通过行为学实验、皮质酮水平检测、血清素（serotonin）水平测定以及肾上腺指数测定，对大鼠的心理生理状态与下丘脑-垂体-肾上腺轴（hypothalamic-pituitary-adrenal axis，HPA轴）功能进行评估；采用16S rDNA扩增子测序技术分析肠道菌群的组成变化，并开展基因功能预测。
结果显示，经舒肝解郁胶囊干预后，慢性不可预见性温和应激抑郁模型大鼠的抑郁样行为得到显著改善；皮质酮水平与肾上腺指数均明显降低，血清素水平显著升高；菌群α、β多样性分析表明，肠道菌群的丰富度与均匀度均有所提升。
舒肝解郁胶囊可调控放线菌门（Actinobacteria）、丹毒丝菌科（Erysipelotrichaceae）、双歧杆菌科（Bifidobacteriaceae）、阿托波菌科（Atopobiaceae）、杜氏菌属（Dubosiella）以及双歧杆菌属（Bifidobacterium）的相对丰度。
线性判别分析效应量（linear discriminant analysis effect size，LEfSe）分析显示，乳酸杆菌科（Lactobacillaceae，科水平）、乳酸杆菌属（Lactobacillus，属水平）、乳杆菌目（Lactobacillales，目水平）、芽孢杆菌纲（Bacilli，纲水平）以及罗伊氏乳杆菌（Lactobacillus-reuteri，种水平）为舒肝解郁胶囊组样本的特征菌群，且这些菌群可能参与调控碳水化合物代谢、氨基酸代谢以及信号转导等代谢通路。
本研究数据明确阐明了舒肝解郁胶囊对肠道菌群的调控作用，为进一步揭示这类传统抗抑郁中药的治疗机制奠定了研究基础。未来可进一步探索舒肝解郁胶囊通过调控肠道菌群结构与功能，改善慢性不可预见性温和应激诱导抑郁的抗抑郁作用潜力。