Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
Department of Pediatrics, University of California San Diego, La Jolla, CA, USA.
ISME J. 2021 May;15(5):1359-1371. doi: 10.1038/s41396-020-00855-0. Epub 2020 Dec 17.
Changes in the gut microbiota during pathogen infection are often predicted to influence disease outcomes. However, studies exploring whether pathogens induce microbiota shifts have yielded inconsistent results. This suggests that variation in infection, rather than the presence of infection alone, might shape pathogen-microbiota relationships. For example, most hosts are coinfected with multiple pathogens simultaneously, and hosts vary in how long they are infected, which may amplify or diminish microbial shifts expected in response to a focal pathogen. We used a longitudinal anthelmintic treatment study of free-ranging African buffalo (Syncerus caffer) to examine whether (i) coinfection with bovine tuberculosis (Mycobacterium bovis, TB) and gastrointestinal nematodes, and (ii) the duration of TB infection, modified effects of single pathogens on the gut microbiota. By accounting for the interaction between TB and nematodes, we found that coinfection affected changes in microbial abundance associated with single infections. Furthermore, the duration of TB infection predicted more microbiota variation than the presence of TB. Importantly, coinfection and infection duration had nearly as much influence on microbial patterns as demographic and environmental factors commonly examined in microbiota research. These findings demonstrate that acknowledging infection heterogeneities may be crucial to understanding relationships between pathogens and the gut microbiota.
肠道微生物群在病原体感染期间的变化通常被预测会影响疾病结局。然而，探索病原体是否会引起微生物群转移的研究结果并不一致。这表明，感染的变化，而不仅仅是感染的存在，可能会影响病原体-微生物群的关系。例如，大多数宿主同时被多种病原体共感染，而且宿主感染的时间长短不同，这可能会放大或减少对焦点病原体的预期微生物转移。我们使用了一项对自由放养的非洲野牛（Syncerus caffer）进行的纵向驱虫治疗研究，以检验以下两种情况：（i）是否与牛结核病（Mycobacterium bovis，TB）和胃肠道线虫共感染，以及（ii）TB 感染的持续时间，是否会改变单一病原体对肠道微生物群的影响。通过考虑 TB 和线虫之间的相互作用，我们发现共感染会影响与单一感染相关的微生物丰度变化。此外，TB 感染的持续时间比 TB 的存在预测了更多的微生物变异。重要的是，共感染和感染持续时间对微生物模式的影响几乎与在微生物组研究中通常检查的人口统计学和环境因素一样大。这些发现表明，认识到感染的异质性可能是理解病原体与肠道微生物群之间关系的关键。
