Halmos Tamás, Suba Ilona
Metabolikus Ambulancia, Mazsihisz Szeretet Kórház Budapest.
Tüdőgondozó, Bajcsy-Zsilinszky Kórház-Rendelőintézet Budapest.
Orv Hetil. 2016 Jan 3;157(1):13-22. doi: 10.1556/650.2015.30296.
The intestinal microbiota is well-known for a long time, but due to newly recognized functions, clinician's attention has turned to it again in the last decade. About 100 000 billion bacteria are present in the human intestines. The composition of bacteriota living in diverse parts of the intestinal tract is variable according to age, body weight, geological site, and diet as well. Normal bacteriota defend the organism against the penetration of harmful microorganisms, and has many other functions in the gut wall integrity, innate immunity, insulin sensitivity, metabolism, and it is in cross-talk with the brain functions as well. It's a recent recognition, that intestinal microbiota has a direct effect on the brain, and the brain also influences the microbiota. This two-way gut-brain axis consists of microbiota, immune and neuroendocrine system, as well as of the autonomic and central nervous system. Emerging from fermentation of carbohydrates, short-chain fatty acids develop into the intestines, which produce butyrates, acetates and propionates, having favorable effects on different metabolic processes. Composition of the intestinal microbiota is affected by the circadian rhythm, such as in shift workers. Dysruption of circadian rhythm may influence intestinal microbiota. The imbalance between the microbiota and host organism leads to dysbacteriosis. From the membrane of Gram-negative bacteria lipopolysacharides penetrate into the blood stream, via impaired permeability of the intestinal mucosa. These processes induce metabolic endotoxaemia, inflammation, impaired glucose metabolism, insulin resistance, obesity, and contribute to the development of metabolic syndrome, type 2 diabetes, inflammarory bowel diseases, autoimmunity and carcinogenesis. Encouraging therapeutic possibility is to restore the normal microbiota either using pro- or prebiotics, fecal transplantation or bariatric surgery. Human investigations seem to prove that fecal transplant from lean healthy individuals into obese diabetic patients improved all the pathological parameters. Wide spread use of bariatric surgery altered gut microbiota and improved metabolic parameters apart from surgery itself. Pathomechanism is not yet completely clarified. Clinicians hope, that deeper understanding of complex functions of intestinal microbiota will contribute to develop more effective therapeutic proceedings against diabetes, metabolic syndrome, and obesity.
肠道微生物群早已为人所知，但由于其新发现的功能，在过去十年中临床医生的注意力再次转向了它。人体肠道中存在约10万亿个细菌。生活在肠道不同部位的细菌群落组成会因年龄、体重、地理位置和饮食而有所不同。正常的细菌群落可保护机体免受有害微生物的侵入，并且在维持肠壁完整性、先天免疫、胰岛素敏感性、新陈代谢等方面具有许多其他功能，还与大脑功能相互作用。最近人们认识到，肠道微生物群对大脑有直接影响，大脑也会影响微生物群。这种肠道与大脑的双向轴由微生物群、免疫和神经内分泌系统以及自主神经系统和中枢神经系统组成。碳水化合物发酵产生的短链脂肪酸在肠道中生成，包括丁酸、乙酸和丙酸，它们对不同的代谢过程具有有益作用。肠道微生物群的组成受昼夜节律影响，如轮班工作者。昼夜节律紊乱可能会影响肠道微生物群。微生物群与宿主生物体之间的失衡会导致菌群失调。革兰氏阴性菌的脂多糖通过受损的肠黏膜通透性进入血流。这些过程会引发代谢性内毒素血症、炎症、葡萄糖代谢受损、胰岛素抵抗、肥胖，并促进代谢综合征、2型糖尿病、炎症性肠病、自身免疫和癌症的发生。令人鼓舞的治疗方法是使用益生菌或益生元、粪便移植或减肥手术来恢复正常的微生物群。人体研究似乎证明，将瘦健康个体的粪便移植到肥胖糖尿病患者体内可改善所有病理参数。减肥手术的广泛应用除了手术本身外，还改变了肠道微生物群并改善了代谢参数。发病机制尚未完全阐明。临床医生希望，对肠道微生物群复杂功能的更深入了解将有助于开发针对糖尿病、代谢综合征和肥胖症的更有效治疗方法。
