Spatial Distribution of Gut Microbiota in KM Mice at the Micrometer Scale

肠道菌群对宿主的健康具有重要影响。目前，相关研究多使用宏观尺度样品(毫米至厘米级)，而对于微观尺度(The gut microbiota exerts significant impacts on host health. Current studies primarily utilize bulk samples (millimeter to centimeter), while systematic understanding of the spatial distribution characteristics of microbial communities at micrometer resolutions (<100 μm) remains limited. In this study, we analyzed 7 Kunming mice using 16S rRNA gene amplicon sequencing, including 378 colonic micro-scale grains (20~40 μm) and 32 bulk samples. Distinct spatial heterogeneity in both taxonomic and functional gene composition of gut microbiota in Kunming mice were observed, with functional heterogeneity being significantly lower than taxonomic heterogeneity. Micro-scale grains accommodated significantly fewer species and functional genes compared to bulk samples, while exhibiting significantly greater inter-grain variability in both taxonomic and functional compositions. Co-occurrence networks constructed from bulk samples and micro-scale grains displayed marked topological differences. This study expands our understanding of spatial distribution patterns in gut microbial communities at micrometer scale, and demonstrates that interspecies relationships inferred from samples of different scales exhibit substantial discrepancies.