该研究探讨不同益生菌对来曲唑诱导的多囊卵巢综合征（Polycystic Ovarian Syndrome，PCOS）大鼠症状的改善作用。经干预后观察大鼠体质量、Lee`s指数、内脏脂肪质量及动情周期变化；采用H&E染色、Masson染色观察大鼠卵巢组织病理及纤维化改变；酶联免疫吸附法检测大鼠血清性激素相关指标（T、E2、LH、FSH）、血脂相关指标（TC、TG、LDL-C、HDL-C）、胰岛素（INS）与脂多糖（LPS）水平；蛋白质印迹法检测大鼠卵巢TGF-β1/Smads信号通路蛋白表达水平。乳双歧杆菌、丁酸梭菌、植物乳杆菌均能有效改善PCOS大鼠体质量，恢复动情周期及卵巢组织多囊样病变，有效调节PCOS组大鼠性激素（T：48.49、45.71、40.36 nmol/L；E2：46.63、42.94、49.94 ng/L；FSH：15.94、17.77、18.73 IU/L；LH：18.73、18.94、17.27 ng/L）、血脂（TG：0.59、0.69、0.79 mmol/L；TC：4.65、4.72、4.48 mmol/L；LDL-C：0.39、0.42、0.44 mmol/L；HDL-C：1.99、1.53、1.39 mmol/L）和LPS水平（102.62、152.8、136.58 EU/L）(p<0.05)，减轻胰岛素抵抗状态。三种益生菌也能显著抑制Smad4、p-Smad3和p-Smad2的表达水平。研究提示，乳双歧杆菌、丁酸梭菌、植物乳杆菌对来曲唑诱导的PCOS大鼠均有显著的保护效果。

The effects of Bifidobacterium sp., Clostridium butyricum, and Lactobacillus plantarum on the clinical symptoms of letrozole-induced polycystic ovary syndrome (PCOS) in rats were investigated. During the experiment, the estrus cycle, visceral fat mass and weight, Lee’s index, and fasting plasma glucose levels were monitored. Thereafter, all the PCOS rats were sacrificed and the histological and fibrotic changes in ovarian tissue were observed using hematoxylin-eosin and Masson staining assays. The serum levels of sex hormones, blood lipids, insulin, and lipopolysaccharide were determined by enzyme-linked immunosorbent assay. The expression of key signaling molecules of the TGF-β/Smad signaling pathway, including Smad2, p-Smad2, Smad3, p-Smad3, and Smad4, in the rat ovaries was detected using western blots. Bifidobacterium sp., C. butyricum, and L. plantarum effectively restored the estrous cycle and improved insulin resistance. They significantly modulated the levels of sex hormones (T: 48.49, 45.71, and 40.36 nmol/L; E2: 46.63, 42.94, and 49.94 ng/L; FSH: 15.94, 17.77, and 18.73 IU/L; LH: 18.73, 18.94, and 17.27 ng/L), dyslipidemia (TG: 0.59, 0.69, and 0.79 mmol/L; TC: 4.65, 4.72, and 4.48 mmol/L; LDL-C: 0.40, 0.42, and 0.44 mmol/L; HDL-C: 1.99, 1.53, and 1.39 mmol/L), and LPS (102.62, 152.8, and 136.58 EU/L). Moreover, the intervention by all three probiotics significantly inhibited the expression of Smad4 (52.89%, 29.14%, and 69.80%), p-Smad3 (65.31%, 65.82%, and 78.57%), and p-Smad2 (77.42%, 52.86%, and 56.96%) (p<0.05). Hence, Bifidobacterium sp., C. butyricum, and L. plantarum exert significant protective effects on letrozole-induced PCOS in rats.

国家自然科学基金资助项目（81560530；81760589；81960590）；广西自然科学基金资助项目（2020GXNSFAA159160）；国家级大学生创新创业训练计划项目（202010601031）；人社部“高层次留学人才回国资助计划”（人社厅函[2019]160号）；广西高等学校千名中青年骨干教师培育计划资助（桂教人[2018]18号）；广西壮族自治区卫生健康委员会自筹经费科研课题（Z20200780）；桂林医学院引进人才科研启动基金（04010150001）