School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
Proc Biol Sci. 2021 Jan 13;288(1942):20201810. doi: 10.1098/rspb.2020.1810.
The human gut microbiota is transmitted from mother to infant through vaginal birth and breastfeeding. , a genus that dominates the infants' gut, is adapted to breast milk in its ability to metabolize human milk oligosaccharides; it is regarded as a mutualist owing to its involvement in the development of the immune system. The composition of microbiota, including the abundance of Bifidobacteria, is highly variable between individuals and some microbial profiles are associated with diseases. However, whether and how birth and feeding practices contribute to such variation remains unclear. To understand how early events affect the establishment of microbiota, we develop a mathematical model of two types of Bifidobacteria and a generic compartment of commensal competitors. We show how early events affect competition between mutualists and commensals and microbe-host-immune interactions to cause long-term alterations in gut microbial profiles. Bifidobacteria associated with breast milk can trigger immune responses with lasting effects on the microbial community structure. Our model shows that, in response to a change in birth environment, competition alone can produce two distinct microbial profiles post-weaning. Adding immune regulation to our competition model allows for variations in microbial profiles in response to different feeding practices. This analysis highlights the importance of microbe-microbe and microbe-host interactions in shaping the gut populations following different birth and feeding modes.
人类肠道微生物群通过阴道分娩和母乳喂养从母亲传递给婴儿。双歧杆菌属是婴儿肠道中占主导地位的一个属，它能够代谢人乳寡糖，从而适应母乳；由于其参与免疫系统的发育，双歧杆菌被认为是一种共生体。微生物群的组成，包括双歧杆菌的丰度，在个体之间高度可变，一些微生物特征与疾病有关。然而，出生和喂养方式是否以及如何导致这种变化尚不清楚。为了了解早期事件如何影响微生物群的建立，我们开发了双歧杆菌两种类型和共生竞争者通用隔间的数学模型。我们展示了早期事件如何影响共生体和共生体之间的竞争以及微生物-宿主-免疫相互作用，从而导致肠道微生物群谱的长期改变。与母乳相关的双歧杆菌可以引发具有持久影响的免疫反应微生物群落结构。我们的模型表明，在出生环境发生变化的情况下，仅竞争就可以在断奶后产生两种截然不同的微生物群谱。在我们的竞争模型中添加免疫调节可以使微生物群谱根据不同的喂养方式发生变化。这种分析强调了微生物-微生物和微生物-宿主相互作用在塑造不同出生和喂养方式后的肠道种群方面的重要性。
