肠道菌群如何通过胆汁酸代谢影响血糖和脂代谢？
How does the gut microbiome influence glucose and lipid metabolism through bile acids?
肝脏合成的初级胆汁酸进入肠道后，被细菌的胆盐水解酶去结合，并经7α-脱羟基作用转化为脱氧胆酸、石胆酸等次级胆汁酸，从而改变整个胆汁酸池的组成。不同胆汁酸对肠道核受体FXR和膜受体TGR5的激动强度差异很大，进而调节GLP-1分泌、肝脏糖异生和棕色脂肪的能量消耗。因此菌群结构改变可以通过胆汁酸信号影响糖脂代谢，这也是相关代谢病药物研发的重要靶点方向。
Primary bile acids made by the liver enter the gut where bacterial bile salt hydrolases deconjugate them and 7-alpha-dehydroxylation converts them into secondary bile acids such as deoxycholic and lithocholic acid, reshaping the whole bile acid pool. Different bile acids differ greatly in how strongly they activate the nuclear receptor FXR and the membrane receptor TGR5, which in turn modulate GLP-1 secretion, hepatic gluconeogenesis and energy expenditure in brown fat. A shifted microbial community can therefore alter glucose and lipid metabolism through bile acid signalling, which is why this axis is an active drug target in metabolic disease.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Nature Medicine（肠道菌群、胆汁酸与代谢性疾病研究）
Nature Medicine (research on gut microbiota, bile acids and metabolic disease)
#胆汁酸 #FXR与TGR5 #糖脂代谢
三甲胺氧化物（TMAO）为什么被认为与心血管风险有关？
Why is trimethylamine N-oxide linked to cardiovascular risk?
肠道细菌把红肉、蛋黄卵磷脂和左卡尼汀中的胆碱类底物代谢为三甲胺，经门脉进入肝脏后由黄素单加氧酶FMO3氧化为TMAO。队列研究发现血TMAO水平升高与心肌梗死、卒中等主要心血管事件风险增加相关，机制研究提示它可增强血小板反应性、促进巨噬细胞泡沫化和胆固醇逆向转运受损。目前TMAO仍属研究性标志物，尚未成为常规临床检测项目或明确的治疗靶点。
Gut bacteria convert choline-containing substrates from red meat, egg phosphatidylcholine and L-carnitine into trimethylamine, which reaches the liver by the portal vein and is oxidised to TMAO by flavin monooxygenase 3. Cohort studies find that higher blood TMAO is associated with increased risk of major cardiovascular events such as myocardial infarction and stroke, and mechanistic work suggests it heightens platelet reactivity, promotes macrophage foam-cell formation and impairs reverse cholesterol transport. TMAO remains a research biomarker and is not yet a routine clinical test or an established therapeutic target.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
《新英格兰医学杂志》(NEJM)（Tang 等，肠道菌群磷脂酰胆碱代谢与心血管风险，2013）
NEJM (Tang et al., intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk, 2013)
#TMAO #FMO3 #心血管风险标志物
粪菌移植目前证据最明确的适应症是什么？
For which condition is faecal microbiota transplantation best supported by evidence?
复发性艰难梭菌感染是粪菌移植证据最强的适应症，随机对照试验显示其治愈率明显高于单纯万古霉素方案，机制在于恢复被抗生素破坏的菌群多样性，通过营养竞争和次级胆汁酸生成抑制艰难梭菌芽孢萌发。用于炎症性肠病、代谢综合征、肝病等适应症的研究结果尚不一致，仍属探索阶段。粪菌移植需要严格筛查供体以避免病原体和耐药菌传播，属于规范医疗操作而非保健方式。
Recurrent Clostridioides difficile infection is the indication with the strongest evidence: randomised trials show cure rates clearly higher than vancomycin alone, because transplantation restores the antibiotic-depleted microbial community, which suppresses C. difficile through nutrient competition and secondary bile acid production that inhibits spore germination. Trials in inflammatory bowel disease, metabolic syndrome and liver disease have given inconsistent results and remain exploratory. Donor screening must be rigorous to avoid transmitting pathogens or resistant organisms, so this is a regulated medical procedure rather than a wellness practice.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
《新英格兰医学杂志》(NEJM)（van Nood 等，粪菌输注治疗复发性艰难梭菌感染，2013）
NEJM (van Nood et al., duodenal infusion of donor faeces for recurrent C. difficile, 2013)
#粪菌移植 #艰难梭菌 #次级胆汁酸
益生菌到底有没有用？现有证据支持哪些用途？
Do probiotics actually work, and which uses are supported by evidence?
益生菌的作用具有明显的菌株特异性和剂量依赖性，不同产品不能一概而论。证据相对一致的是特定菌株可缩短儿童急性感染性腹泻病程、降低抗生素相关腹泻发生率，以及减少极低出生体重早产儿坏死性肠炎风险；而声称提高普通人群免疫力、减重或治疗慢性病的证据仍不充分。一般建议按明确适应症选择有临床数据支持的具体菌株，重度免疫抑制或危重患者使用前应咨询医生。
Probiotic effects are strain-specific and dose-dependent, so results cannot be generalised across products. The most consistent evidence is that particular strains shorten acute infectious diarrhoea in children, reduce antibiotic-associated diarrhoea, and lower the risk of necrotising enterocolitis in very-low-birthweight preterm infants, whereas claims about boosting immunity, weight loss or treating chronic disease in healthy adults remain poorly supported. It is generally advised to choose a specific strain with clinical data for a defined indication, and for severely immunocompromised or critically ill patients to consult a doctor first.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
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葛均波 等主编,《内科学》第9版,人民卫生出版社,2018
Ge Junbo et al. eds., Internal Medicine, 9th ed., PMPH, 2018
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787117265416（豆瓣书目条目: 内科学）
#益生菌 #菌株特异性 #临床证据
改变饮食后肠道菌群多久会发生变化？
How quickly does the gut microbiome change after a change in diet?
饮食结构的大幅改变可在数天内改变菌群的组成和代谢活性：以动物性食物为主时耐胆汁的菌属增多，高纤维植物性饮食则促进能发酵纤维、产短链脂肪酸的菌群扩张。但这种快速变化多数可逆，恢复原饮食后菌群往往回到接近原来的状态，长期饮食习惯才决定菌群的稳定格局。因此偶尔一顿饭影响有限，持续增加多样化的植物性食物更有实际意义。
A large shift in diet can change microbial composition and metabolic activity within days: animal-based eating patterns favour bile-tolerant genera, while high-fibre plant-based diets expand fibre-fermenting, short-chain-fatty-acid-producing taxa. These rapid changes are mostly reversible, and the community tends to return towards its previous state once the usual diet resumes, so it is long-term habit that sets the stable configuration. A single meal therefore matters little, whereas consistently adding diverse plant foods is what counts.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
葛均波 等主编,《内科学》第9版,人民卫生出版社,2018
Ge Junbo et al. eds., Internal Medicine, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787117265416（豆瓣书目条目: 内科学）
#饮食与菌群 #可逆性 #植物性膳食
抗生素为什么会扰乱肠道菌群？停药后能恢复吗？
Why do antibiotics disturb the gut microbiome, and does it recover afterwards?
广谱抗生素在杀灭致病菌的同时也清除大量共生菌，导致菌群多样性下降，原本被竞争抑制的耐药菌或真菌趁机过度生长，临床可表现为腹泻，严重时出现艰难梭菌感染。多数人的菌群在停药后数周至数月内大致恢复，但部分菌种可能长期不能回到原有水平，耐药基因也会在群落中留存。一般建议严格按适应症和疗程使用抗生素，不因普通病毒性感冒自行服药。
Broad-spectrum antibiotics kill commensal bacteria along with pathogens, lowering community diversity and letting resistant bacteria or fungi that were previously held in check overgrow, which can cause diarrhoea and in severe cases C. difficile infection. In most people the microbiome largely recovers within weeks to months after stopping, but some taxa may never return to baseline levels and resistance genes can persist in the community. It is generally advised to use antibiotics only for appropriate indications and full courses, and not to self-medicate for ordinary viral colds.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
葛均波 等主编,《内科学》第9版,人民卫生出版社,2018
Ge Junbo et al. eds., Internal Medicine, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787117265416（豆瓣书目条目: 内科学）
#抗生素 #菌群多样性 #艰难梭菌感染
「肠-脑轴」到底指什么？
What exactly does the gut-brain axis refer to?
肠-脑轴指肠道与中枢神经系统之间的双向沟通网络，途径包括迷走神经等神经通路、下丘脑-垂体-肾上腺轴的激素信号、免疫细胞因子，以及菌群代谢产物如短链脂肪酸和色氨酸衍生物。这解释了紧张时会腹痛腹泻、肠道炎症时容易情绪低落等日常现象。虽然动物实验提示菌群可影响行为，但把人类情绪或精神疾病简单归因于某一种细菌，目前仍缺乏充分证据。
The gut-brain axis is the two-way communication network between the intestine and the central nervous system, operating through neural routes such as the vagus nerve, hormonal signals of the hypothalamic-pituitary-adrenal axis, immune cytokines, and microbial metabolites including short-chain fatty acids and tryptophan derivatives. It explains everyday observations such as abdominal pain or diarrhoea under stress and low mood during intestinal inflammation. Animal work suggests microbes can influence behaviour, but attributing human mood or psychiatric disorders to a single bacterium is not yet supported by adequate evidence.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
葛均波 等主编,《内科学》第9版,人民卫生出版社,2018
Ge Junbo et al. eds., Internal Medicine, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787117265416（豆瓣书目条目: 内科学）
#肠-脑轴 #迷走神经 #菌群代谢产物
短链脂肪酸是什么？它在人体代谢中起什么作用？
What are short-chain fatty acids and what do they do in human metabolism?
结肠中的细菌发酵膳食纤维和抗性淀粉，产生乙酸、丙酸和丁酸等短链脂肪酸。丁酸是结肠上皮细胞的主要能量来源，有助于维持黏膜屏障完整性；丙酸主要经门脉进入肝脏参与糖异生调控；乙酸可进入外周循环并影响食欲与脂代谢信号。这是高纤维饮食被认为有利于肠道与代谢健康的重要机制之一。
Bacteria in the colon ferment dietary fibre and resistant starch into short-chain fatty acids, mainly acetate, propionate and butyrate. Butyrate is the primary fuel for colonic epithelial cells and helps maintain mucosal barrier integrity, propionate travels via the portal vein to the liver where it influences gluconeogenesis, and acetate reaches the systemic circulation and affects appetite and lipid signalling. This is one key reason a high-fibre diet is considered good for gut and metabolic health.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-03
来源 · Source
《生理学》（结肠发酵与短链脂肪酸的吸收利用）
Physiology (colonic fermentation and absorption of short-chain fatty acids)
#短链脂肪酸 #膳食纤维发酵 #丁酸