微生物发酵中药YA3D3通过调控肠道菌群-短链脂肪酸-神经递质轴改善APP/PS1小鼠认知障碍

Microbial fermentation of traditional Chinese medicine YA3D3 ameliorates cognitive impairment in APP/PS1 mice by regulating the gut microbiota-short-chain fatty acids-neurotransmitter axis

摘要:

目的 探究微生物发酵中药YA3D3通过微生物-肠-脑轴改善APP/PS1转基因阿尔茨海默病(Alzheimer’s disease, AD)模型小鼠认知功能的机制。方法 对APP/PS1小鼠分别给予YA3D3水提物(YA3D3-HF)及其微生物发酵产物(YA3D3-MHF)干预90 d，采用16S rRNA基因测序分析肠道菌群结构，气相色谱-质谱联用技术(gas chromatography-mass spectrometry, GC-MS)检测粪便短链脂肪酸(short-chain fatty acids, SCFAs)水平，酶联免疫实验(enzyme-linked immunosorbent assay, ELISA)法测定脑组织神经递质含量，Morris水迷宫评估认知功能，结合网络药理学与质谱分析明确活性成分及化学基础变化。结果 与模型组(model, BC)及YA3D3-HF组相比，YA3D3-MHF能更显著改善小鼠认知障碍；Morris水迷宫显示YA3D3-MHF-H (MH)组逃避潜伏期最短、穿越平台次数最多，接近正常对照组(control, NM)；ELISA证实MH组脑内5-羟色胺(5-hydroxytryptamine, 5-HT)、γ-氨基丁酸(γ-aminobutyric acid, GABA)、谷氨酸(glutamate, GLU)含量最高；16S rRNA基因测序显示MH组肠道菌群α多样性(Shannon指数约3.2)及有益菌丰度最高，促炎菌丰度最低；GC-MS表明MH组总SCFAs、乙酸、丁酸含量最高。质谱分析显示YA3D3-MHF成分极性降低且活性峰增高。结论 YA3D3-MHF通过调控肠道菌群-SCFAs-神经递质轴改善AD小鼠认知功能，效果优于传统水提物，为靶向肠-脑轴的AD干预提供实验依据。

Abstract:

Objective To investigate the mechanism by which the microbial fermentation product of the traditional Chinese medicine YA3D3 (YA3D3-MHF) improves cognitive function in the APP/PS1 transgenic mouse model of Alzheimer’s disease (AD) via the microbiota-gut-brain axis.Methods APP/PS1 mice were administered either the water extract of YA3D3 (YA3D3-HF) or YA3D3-MHF for 90 days. The gut microbiota structure was analyzed by 16S rRNA gene sequencing, and the fecal levels of short-chain fatty acids (SCFAs) were assessed by GC-MS. The neurotransmitter content in the brain tissue was measured via ELISA, and cognitive function was assessed via the Morris water maze. Network pharmacology and mass spectrometry were employed to identify active components and changes in chemical composition.Results Compared with the model group and the YA3D3-HF group, YA3D3-MHF significantly ameliorated cognitive impairment in mice. The Morris water maze test showed that the high-dose YA3D3-MHF (MH) group had the shortest escape latency and the highest number of platform crossings, approaching the performance of the normal control group. ELISA confirmed that the MH group had the highest levels of 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (GABA), and glutamate (GLU) in the brain. The results of 16S rRNA gene sequencing revealed that the MH group exhibited the highest alpha diversity (Shannon index≈3.2) of gut microbiota and the highest abundance of beneficial bacteria, along with the lowest abundance of pro-inflammatory bacteria. GC-MS analysis indicated that the MH group had the highest levels of total SCFAs, acetate, and butyrate. MS demonstrated that YA3D3-MHF components exhibited reduced polarity and the emergence of new high-activity peaks.Conclusion YA3D3-MHF improves cognitive function in AD mice by modulating the gut microbiota-SCFAs-neurotransmitter axis, outperforming YA3D3-HF. This study provides experimental evidence for AD intervention targeting the gut-brain axis.