小柯机器人

美国斯坦福大学Michael R. Howitt小组发现，共生原生动物的代谢多样性调节肠道免疫和跨界竞争。相关论文于2023年12月13日在线发表在《细胞》杂志上。

研究人员发现了与人类和啮齿动物相关的parabasalid原生动物，并揭示了它们在非工业化人类群体中的多样性和普遍性。对三毛滴虫属小鼠parabasalid的基因组和代谢组分析表明，代谢物琥珀酸的排泄存在物种水平差异，这导致了不同的小肠免疫反应。三毛滴虫属物种之间的代谢差异也决定了它们在微生物群中的生态位。

通过操纵膳食纤维和开发体外原生动物培养，研究人员发现不同的三毛滴虫属物种偏好膳食多糖或粘液糖。这些多糖偏好推动了与特定共生菌的跨界竞争，从而以依赖饮食的方式影响肠道免疫。这项发现揭示了共生寄生菌中未被重视的多样性，阐明了共生原生动物代谢的差异，并提出了如何通过饮食干预来调节它们对肠道健康的影响。

据了解，微生物群影响着肠道健康和生理学，然而共生原生动物对肠道环境的贡献却在很大程度上被忽视了。

附：英文原文

Title: Metabolic diversity in commensal protists regulates intestinal immunity and trans-kingdom competition

Author: Elias R. Gerrick, Soumaya Zlitni, Patrick T. West, Matthew M. Carter, Claire M. Mechler, Matthew R. Olm, Elisa B. Caffrey, Jessica A. Li, Steven K. Higginbottom, Christopher J. Severyn, Frauke Kracke, Alfred M. Spormann, Justin L. Sonnenburg, Ami S. Bhatt, Michael R. Howitt

Issue&Volume: 2023-12-13

Abstract: The microbiota influences intestinal health and physiology, yet the contributionsof commensal protists to the gut environment have been largely overlooked. Here, wediscover human- and rodent-associated parabasalid protists, revealing substantialdiversity and prevalence in nonindustrialized human populations. Genomic and metabolomicanalyses of murine parabasalids from the genus Tritrichomonas revealed species-level differences in excretion of the metabolite succinate, whichresults in distinct small intestinal immune responses. Metabolic differences betweenTritrichomonas species also determine their ecological niche within the microbiota. By manipulatingdietary fibers and developing in vitro protist culture, we show that different Tritrichomonas species prefer dietary polysaccharides or mucus glycans. These polysaccharide preferencesdrive trans-kingdom competition with specific commensal bacteria, which affects intestinalimmunity in a diet-dependent manner. Our findings reveal unappreciated diversity incommensal parabasalids, elucidate differences in commensal protist metabolism, andsuggest how dietary interventions could regulate their impact on gut health.

DOI: 10.1016/j.cell.2023.11.018

Source: https://www.cell.com/cell/fulltext/S0092-8674(23)01271-0