Ecophysiolosical consequences of chronic ethanol consumption on human gut microbiota: implications for the pathogenesis of ethanol-related colorectal cancer

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K14682
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied microbiology
• Research Institution: Tohoku University
• Principal Investigator: Nakayama Toru 東北大学, 工学研究科, 教授 (80268523)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: acetaldehyde / alcoholism / gut microbiota / intestinal bacteria

Outline of Final Research Achievements

To find roles of gut microbes and their acetaldehyde metabolism in the pathogenesis of ethanol-related colorectal cancer, the gut microbiota structures of non-alcoholics and alcoholics were analyzed and compared. The gut microbiotas of alcoholics were diminished in dominant obligate anaerobes and enriched in Streptococcus and other minor species. This alteration might be exacerbated by habitual smoking. These observations could at least partly be explained by the susceptibility of obligate anaerobes to reactive oxygen species, which are increased by chronic exposure of the gut mucosa to ethanol. The acetaldehyde productivity from ethanol was much lower in the faeces of alcoholic patients than in faeces of non-alcoholic subjects. Based on these results, a model has been proposed, in which oxidative dress induced upon chronic ethanol consumption serves as an important risk factor in the pathogenesis of ethanol-related colorectal cancer.

Free Research Field

生化学