Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Howard Hughes Medical Institute, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Mol Microbiol. 2024 Sep;122(3):304-312. doi: 10.1111/mmi.15270. Epub 2024 May 1.
The small intestine represents a complex and understudied gut niche with significant implications for human health. Indeed, many infectious and non-infectious diseases center within the small intestine and present similar clinical manifestations to large intestinal disease, complicating non-invasive diagnosis and treatment. One major neglected aspect of small intestinal diseases is the feedback relationship with the resident collection of commensal organisms, the gut microbiota. Studies focused on microbiota-host interactions in the small intestine in the context of infectious and non-infectious diseases are required to identify potential therapeutic targets dissimilar from those used for large bowel diseases. While sparsely populated, the small intestine represents a stringent commensal bacterial microenvironment the host relies upon for nutrient acquisition and protection against invading pathogens (colonization resistance). Indeed, recent evidence suggests that disruptions to host-microbiota interactions in the small intestine impact enteric bacterial pathogenesis and susceptibility to non-infectious enteric diseases. In this review, we focus on the microbiota's impact on small intestine function and the pathogenesis of infectious and non-infectious diseases of the gastrointestinal (GI) tract. We also discuss gaps in knowledge on the role of commensal microorganisms in proximal GI tract function during health and disease.
小肠是一个复杂且研究不足的肠道生态位，对人类健康有重大影响。事实上，许多传染性和非传染性疾病都集中在小肠内，并表现出与大肠疾病相似的临床症状，从而使非侵入性诊断和治疗变得复杂。小肠疾病的一个主要被忽视的方面是与常驻共生体——肠道微生物群的反馈关系。需要研究聚焦于在感染和非传染性疾病背景下，小肠内的微生物群-宿主相互作用，以确定与大肠疾病不同的潜在治疗靶点。尽管小肠内的共生细菌数量稀少，但它代表了一种严格的共生细菌微环境，宿主依赖于它来获取营养物质并抵御入侵病原体（定植抵抗）。事实上，最近的证据表明，小肠内宿主-微生物群相互作用的破坏会影响肠道细菌的发病机制，并使宿主易患非传染性肠道疾病。在这篇综述中，我们重点关注微生物群对小肠功能和胃肠道（GI）感染和非传染性疾病发病机制的影响。我们还讨论了在健康和疾病期间，关于共生微生物在近端胃肠道功能中的作用的知识空白。
