| 特集名 | 細菌と消化器疾患 -- 病因，病態とその制御に向けて | |
|---|---|---|
| 題名 | ASH,NASHと腸内細菌 | |
| 発刊年月 | 2007年 08月 | |
| 著者 | 大草 敏史 | 順天堂大学医学部消化器内科 |
| 著者 | 佐藤 信紘 | 大阪けいさつ病院 |
| 【 要旨 】 | アルコール性脂肪性肝炎 (ASH) は，アルコールによる粘膜透過性亢進により，エンドトキシンが多量に門脈内に流入して，肝のKupffer細胞を刺激し，TNF-αなどの炎症性サイトカイン産生を増強することで，肝細胞壊死やアポトーシス，線維化を引き起こすと考えられてきたが，非アルコール性脂肪性肝炎 (NASH) においても，腸内細菌によるアルコールの産生や腸内細菌の異常増殖により，ASHと同様の機序で肝細胞壊死やアポトーシス，線維化が起こるという説が出ている．また，遺伝的背景として，ASHとNASHともに，Kupffer細胞にあるエンドトキシン受容体のCD 14の発現が増強し，エンドトキシンに対する感受性が亢進していることも知られている．さらに，抗菌薬やプロバイオティクスの投与でASH，NASHともに発症抑制や病変改善も報告されている．すなわち，ASHとNASHの病態形成には，インスリン抵抗性だけでなく，腸内細菌が有するエンドトキシンが深く関わっていると考えられる | |
| Theme | Digestive Diseases Related to Bacteria -- To Understand Etiology and Control of Clinicopathological Conditions | |
|---|---|---|
| Title | Correlations between Alcoholic Steatohepatitis, Nonalcoholic Steatohepatitis and Intestinal Bacteria | |
| Author | Toshifumi Ohkusa | Department of Gastroenterology, Juntendo University School of Medicine |
| Author | Nobuhiro Sato | Osaka Police Hospital |
| [ Summary ] | It is hypothesized that is relation to alcoholic steatohepatitis, ethanol consumption increase the permeability of the small intestine and endotoxins are produced which incite necroinflammatory changes in connection steatohepatitis and hepatic fibrosis. Endotoxins are potent inducers of proinflammatory and cytotoxic cytokines, such as tumor necrosis factorα (TNF-α) from activated macrophages, including Kupffer cells. It is known that severe steatohepatitis occurres after jejunoileal bypass surgery for obesity and resection of the redundant intestinal loop with its bacterial flora, or treatment with antibiotics for small intestinal bacterial overgrowth (SIBO) improves nonalcoholic steatohepatitis (NASH) in rat models of jejunoileal-bypass liver disease. It has been reported that patients with NASH have a higher prevalence of SIBO. These findings suggest that gut derived bacterial endotoxins could be involved in triggering liver injury in conjunction with NASH. Recently, intestinal bacteria have been studied with new molecular, biological techniques instead of the culture method. Therefore, it is proposed that causal bacteria in portal NASH blood should be searched for. Causal bacteria derived endotoxins, related to NASH, have been detected. Eradication therapy for the bacteria may bring improvements in NASH. |
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