Major Anaerobic Bacteria Responsible for the Production of Carcinogenic Acetaldehyde from Ethanol in the Colon and Rectum
Major Anaerobic Bacteria Responsible for the Production of Carcinogenic Acetaldehyde from Ethanol in the Colon and Rectum
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DOI：
10.1093/alcalc/agv135
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发表时间：
2016-07-01
影响因子：
2.8
通讯作者：
Nakayama, Toru
中科院分区：
文献类型：
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作者：
Tsuruya, Atsuki;Kuwahara, Akika;Nakayama, Toru
肠道需氧菌和兼性厌氧菌在好氧条件下乙醇氧化在乙醇相关性结直肠癌发病机制中的重要性已经被提出。然而，其中的专门厌氧菌的作用仍有待确定，并且尚不清楚哪种细菌种类（如果有的话）在这种条件下对致癌乙醛的产生和/或消除最重要。进行这项研究就是为了解决这些问题。从日本酗酒者的粪便中分离出500多株细菌，并对其进行了系统发育鉴定，并在体外研究了它们的有氧乙醇代谢，以检验它们在超过最小致突变浓度（MMC, 50 A μ M）的情况下积累乙醛的能力。在结肠和直肠的有氧条件下，被认为可能在MMC之外积累乙醛的细菌菌株被确定并称为“潜在的乙醛蓄积物”（PAAs）。Ruminococcus是一种专性厌氧菌，被认为是一个包含大量PAAs的属。其他专性厌氧菌也被发现包括PAAs。PAAs在结直肠粘膜表面定植的乙醛积累可以被描述为PAAs对氧化应激的反应，至少部分如此。结肠和直肠中需氧条件下肠道专性厌氧菌对乙醇的氧化也可能在乙醇相关结直肠癌的发病机制中发挥重要作用。
The importance of ethanol oxidation by intestinal aerobes and facultative anaerobes under aerobic conditions in the pathogenesis of ethanol-related colorectal cancer has been proposed. However, the role of obligate anaerobes therein remains to be established, and it is still unclear which bacterial species, if any, are most important in the production and/or elimination of carcinogenic acetaldehyde under such conditions. This study was undertaken to address these issues.More than 500 bacterial strains were isolated from the faeces of Japanese alcoholics and phylogenetically characterized, and their aerobic ethanol metabolism was studied in vitro to examine their ability to accumulate acetaldehyde beyond the minimum mutagenic concentration (MMC, 50 A mu M).Bacterial strains that were considered to potentially accumulate acetaldehyde beyond the MMC under aerobic conditions in the colon and rectum were identified and referred to as 'potential acetaldehyde accumulators' (PAAs). Ruminococcus, an obligate anaerobe, was identified as a genus that includes a large number of PAAs. Other obligate anaerobes were also found to include PAAs. The accumulation of acetaldehyde by PAAs colonizing the colorectal mucosal surface could be described, at least in part, as the response of PAAs to oxidative stress.Ethanol oxidation by intestinal obligate anaerobes under aerobic conditions in the colon and rectum could also play an important role in the pathogenesis of ethanol-related colorectal cancer.