Although Clostridium difficile is widely considered an antibiotic- and hospital-associated pathogen, recent evidence indicates that this is an insufficient depiction of the risks and reservoirs. A common thread that links all major risk factors of infection is their association with gastrointestinal disturbances, but this relationship to C. difficile colonization has never been tested directly. Here, we show that disturbances caused by diarrhoeal events trigger susceptibility to C. difficile colonization. Using survey data of the human gut microbiome, we detected C. difficile colonization and blooms in people recovering from food poisoning and Vibrio cholerae infections. Carriers remained colonized for year-long time scales and experienced highly variable patterns of C. difficile abundance, where increased shedding over short periods of 1-2 d interrupted week-long periods in which C. difficile was undetectable. Given that short shedding events were often linked to gastrointestinal disturbances, our results help explain why C. difficile is frequently detected as a co-infecting pathogen in patients with diarrhoea. To directly test the impact of diarrhoea on susceptibility to colonization, we developed a mouse model of variable disturbance intensity, which allowed us to monitor colonization in the absence of disease. As mice exposed to avirulent C. difficile spores ingested increasing quantities of laxatives, more individuals experienced C. difficile blooms. Our results indicate that the likelihood of colonization is highest in the days immediately following acute disturbances, suggesting that this could be an important window during which transmission could be interrupted and the incidence of infection lowered.

中文翻译：

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腹泻事件可触发长期艰难梭菌定殖并反复开花。

尽管艰难梭菌被广泛认为是与抗生素和医院相关的病原体，但最近的证据表明，这不足以描述风险和储库。与感染的所有主要危险因素相关的一个共同线索是它们与胃肠道疾病的关系，但是这种与艰难梭菌定植的关系从未经过直接测试。在这里，我们显示由腹泻事件引起的干扰触发对艰难梭菌定植的敏感性。使用人类肠道微生物组的调查数据，我们从食物中毒和霍乱弧菌感染中恢复过来的人中检测到艰难梭菌定殖和开花。携带者在长达一年的时间里一直定居下来，并经历了艰难梭菌丰度的高度可变模式，在短短的1-2 d内脱落增加，中断了长达一周的无法检测到艰难梭菌的时期。鉴于短暂的脱落事件通常与胃肠道疾病有关，我们的结果有助于解释为什么艰难梭菌经常被检测为腹泻患者的共同感染病原体。为了直接测试腹泻对定植敏感性的影响，我们开发了可变干扰强度的小鼠模型，使我们能够在没有疾病的情况下监测定植。随着暴露于无毒艰难梭菌孢子的小鼠摄入越来越多的泻药，越来越多的个体经历了艰难梭菌开花。我们的结果表明，在发生急性疾病后的几天内，定植的可能性最高，