你有沒(méi)有聽(tīng)說(shuō)過(guò)肥胖會(huì)在朋友間“傳染”?那是因?yàn)槊苡训纳盍?xí)慣會(huì)互相影響,。
2月刊《自然》雜志上發(fā)表的一項(xiàng)研究成果稱(chēng),,美國(guó)科學(xué)家以老鼠為實(shí)驗(yàn)對(duì)象的研究顯示,肥胖具有傳染性,,能像疾病一樣讓同伴“感染”,。
耶魯大學(xué)醫(yī)學(xué)院研究人員用基因技術(shù)擾亂一些老鼠的免疫系統(tǒng),讓它們患上非酒精性脂肪肝,。與此同時(shí),,給它們吃高油高脂飲食,讓它們變得越來(lái)越胖,。
接下來(lái),,研究人員把這些患有脂肪肝的胖老鼠放到健康老鼠生活的籠子里。他們驚奇地發(fā)現(xiàn),,健康老鼠逐漸出現(xiàn)脂肪肝癥狀,,體型也越來(lái)越胖。
研究人員理查德·弗拉維爾說(shuō),這個(gè)變化過(guò)程中的“罪魁禍?zhǔn)?rdquo;是老鼠胃里的微生物,。
“趣味科學(xué)”網(wǎng)站引述弗拉維爾的話報(bào)道,,動(dòng)物體內(nèi)通常生活著多種菌群,菌群保持相對(duì)平衡,。那些免疫系統(tǒng)受到干擾的老鼠內(nèi)臟中菌群紊亂,,體內(nèi)可能引發(fā)疾病的壞細(xì)菌數(shù)量呈千倍增長(zhǎng)。
弗拉維爾說(shuō),,肥胖在人之間可能會(huì)像在老鼠間那樣傳染,,但還需要進(jìn)一步驗(yàn)證。而且,,肥胖對(duì)老鼠的傳染性更強(qiáng),,因?yàn)槔鲜髸?huì)互食對(duì)方排泄物,這是內(nèi)臟細(xì)菌傳染的一個(gè)有效途徑,。
弗拉維爾說(shuō),,人們應(yīng)當(dāng)嚴(yán)肅對(duì)待肥胖“傳染”問(wèn)題。因?yàn)橹靖卧诜逝秩巳褐邢喈?dāng)常見(jiàn),,75%肥胖人士患有這一疾病,。
脂肪肝是西方國(guó)家中導(dǎo)致慢性肝病的最主要原因。據(jù)估計(jì),,僅在美國(guó),,就有約3000萬(wàn)人受非酒精性脂肪肝影響。其中,,20%會(huì)發(fā)展為慢性肝炎,,這讓他們面臨肝硬化甚至肝癌風(fēng)險(xiǎn)。
先前有研究顯示,,如果一個(gè)家庭有兩名成員患上肝病或者體重超重,,人們通常認(rèn)為這是遺傳問(wèn)題。但是弗拉維爾的研究顯示,,環(huán)境也是影響因素之一,。
他說(shuō),這一研究結(jié)果若應(yīng)用在人身上,,意味著若要治療肝病和肥胖,,除了傳統(tǒng)方法外,還應(yīng)關(guān)注人體內(nèi)的微生物,。
弗吉尼亞聯(lián)邦大學(xué)主攻胃腸,、肝臟與營(yíng)養(yǎng)學(xué)的教授賈斯莫漢·巴賈杰說(shuō),弗拉維爾的研究具有啟迪作用,,“強(qiáng)調(diào)所有人都有的細(xì)菌決定對(duì)肝病的易感性”,。
不過(guò),人體機(jī)能比老鼠復(fù)雜得多,因此還需要進(jìn)一步研究才能確定人與人之間是否同樣能“傳染”,。(生物谷 Bioon.com)
doi:10.1038/nature10809
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Inflammasome-mediated dysbiosis regulates progression of NAFLD and obesity
Jorge Henao-Mejia, Eran Elinav, Chengcheng Jin, Liming Hao, Wajahat Z. Mehal, Till Strowig, Christoph A. Thaiss, Andrew L. Kau, Stephanie C. Eisenbarth, Michael J. Jurczak, Joao-Paulo Camporez, Gerald I. Shulman, Jeffrey I. Gordon, Hal M. Hoffman & Richard A. Flavell
Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and the leading cause of chronic liver disease in the Western world. Twenty per cent of NAFLD individuals develop chronic hepatic inflammation (non-alcoholic steatohepatitis, NASH) associated with cirrhosis, portal hypertension and hepatocellular carcinoma, yet the causes of progression from NAFLD to NASH remain obscure. Here, we show that the NLRP6 and NLRP3 inflammasomes and the effector protein IL-18 negatively regulate NAFLD/NASH progression, as well as multiple aspects of metabolic syndrome via modulation of the gut microbiota. Different mouse models reveal that inflammasome-deficiency-associated changes in the configuration of the gut microbiota are associated with exacerbated hepatic steatosis and inflammation through influx of TLR4 and TLR9 agonists into the portal circulation, leading to enhanced hepatic tumour-necrosis factor (TNF)-α expression that drives NASH progression. Furthermore, co-housing of inflammasome-deficient mice with wild-type mice results in exacerbation of hepatic steatosis and obesity. Thus, altered interactions between the gut microbiota and the host, produced by defective NLRP3 and NLRP6 inflammasome sensing, may govern the rate of progression of multiple metabolic syndrome-associated abnormalities, highlighting the central role of the microbiota in the pathogenesis of heretofore seemingly unrelated systemic auto-inflammatory and metabolic disorders.