目的 聯(lián)合16S rDNA技術(shù)和代謝組學(xué)技術(shù)評價短雙歧桿菌組合（BBC）抗抑郁的活性及作用機(jī)制。方法 選取36只大鼠隨機(jī)分為4組：對照組、模型組、BBC（短雙歧桿菌BBr60∶兩歧雙歧桿菌BBi32∶長雙歧桿菌BL21∶嗜熱鏈球菌ST36＝1∶1∶1∶1，1.5×10⁹ CFU· d^-1）組和氟哌噻噸美利曲辛片（陽性藥，1.0 mg·kg^-1）組，除對照組外建立慢性不可預(yù)知溫和應(yīng)激（CUMS）抑郁大鼠模型，模型成功后ig給藥4周，進(jìn)行糖水偏好實(shí)驗(yàn)、強(qiáng)迫游泳實(shí)驗(yàn)和曠場實(shí)驗(yàn)評價大鼠抑郁行為，酶聯(lián)免疫吸附（ELISA）法測定血清5-羥色胺（5-HT）、多巴胺（DA）和去甲腎上腺素（NE）的水平，蘇木素-伊紅（HE）染色觀察海馬CA1和CA3區(qū)的神經(jīng)元細(xì)胞數(shù)目和形態(tài)變化；應(yīng)用16S rDNA擴(kuò)增子測序和非靶向代謝組學(xué)技術(shù)探討B(tài)BC對抑郁大鼠腸道菌群及代謝產(chǎn)物的調(diào)控作用，結(jié)合Spearman系數(shù)法構(gòu)建差異菌群、代謝產(chǎn)物的關(guān)聯(lián)性。結(jié)果 與模型組比較，BBC可有效改善大鼠抑郁樣行為（P＜0.05、0.01），提高血清中5-HT、DA和NE的水平，增加神經(jīng)元細(xì)胞數(shù)目；有效改善抑郁大鼠的菌群失調(diào)，尤其對Bacilli綱、Lactobacillales目、Lactobacillaceae科和Lactobacillus屬等菌群有回調(diào)作用（P＜0.05、0.01）；采用糞便代謝組學(xué)鑒定出與抗抑郁作用有關(guān)的主要生物標(biāo)志物為1-羥-2-萘甲酸、甘草黃酮A、N-乙酰組胺等，采用血清代謝組學(xué)鑒定出與抗抑郁有關(guān)的主要生物標(biāo)志物為二十二碳五烯酸、順式-11-二十碳烯酸、3'-O-甲基巴塔氨酸III等；同時發(fā)現(xiàn)Lactobacillus和clostridia_UCG-014與差異代謝物存在顯著關(guān)聯(lián)；主要富集的通路是不飽和脂肪酸的生物合成、色氨酸代謝、丁酸代謝和煙酸和煙酰胺代謝等代謝途徑。結(jié)論 BBC可通過干預(yù)相關(guān)腸道菌群和調(diào)節(jié)相關(guān)通路緩解慢性壓力導(dǎo)致的抑郁相關(guān)癥狀。

Objective This study aimed to investigate the antidepressant mechanisms of combination of Bifidobacterium brevis, based on 16S rDNA technology and metabolomics technology. Methods Select 36 rats at random and divide them into four groups: control group, model group, BBC group (Bifidobacterium bifidum BBr60∶Bifidobacterium bifidum BBi32∶Lactobacillus reuteri BL21∶Streptococcus thermophilus ST36 = 1∶1∶1∶1, 1.5×10^-9 CFU · d^-1) and Fluoxetine and Mirtazapine Tablets (positive drug, 1.0 mg·kg^-1), except the control group, to establish a CUMS depression rat model with chronic unpredictable mild stress. After the model was successfully established, the rats were ig administered BBC or Fluoxetine and Mirtazapine Tablets for four weeks. The rat depressive behaviors were evaluated by the sucrose preference test, forced swimming test, and open field test, and the levels of 5-hydroxytryptamine (5-HT), dopamine (DA), and norepinephrine (NE) in the serum were determined by enzyme-linked immunosorbent assay (ELISA). The number and morphological changes of neurons in the hippocampal CA1 and CA3 regions were observed by hematoxylin-eosin (HE) staining. The effects of BBC on the gut microbiota and metabolites of depressed rats were explored by 16S rDNA amplicon sequencing and non-targeted metabolomics, and the correlation between differential gut microbiota and metabolites was established by Spearman's coefficient. Results Compared with the model group, BBC effectively ameliorated depressive-like behaviors (P <0.05 and 0.01), enhanced the levels of 5-HT and DA in the serum and increased the number of neurons in rats. It also restored gut microbiota dysbiosis, particularly by modulating taxa such as Bacilli class, Lactobacillales order, Lactobacillaceae family, and Lactobacillus genus (P <0.05、 0.01). The key biomarkers associated with the antidepressant effect identified through fecal metabolomics included 1-hydroxy-2-naphthoic acid, glycyrrhizin A, and N-acetylhistamine, while serum metabolomics revealed key biomarkers such as docosapentaenoic acid, cis-11-eicosenoic acid, and 3'-O-methylbatanin III. Significant associations were found between Lactobacillus and Clostridia_UCG-014 and differential metabolites. The enriched pathways included unsaturated fatty acid biosynthesis, tryptophan metabolism, butanoate metabolism, and nicotinate and nicotinamide metabolism, among others. Conclusion BBC alleviates depression-related symptoms induced by chronic stress by modulating gut microbiota and regulating associated metabolic pathways.

2022年湖北省自然科學(xué)基金面上類項(xiàng)目（2022CFB849）;2022年湖北省教育廳科學(xué)研究項(xiàng)目（Q20222014）