关键词: 衰老, C57BL/6小鼠, 肠道菌群, 16S rRNA 高通量测序

Abstract: Objective　To investigate the characteristics of gut microbiota in retired aged C57BL/6 mice. Methods　Rectal content samples were collected from female C57BL/6 mice at 8 weeks of age (control group,n=10) and retired mice at 72 weeks of age (aged group,n=10). The V3-V4 hypervariable region of the 16S rRNA gene was amplified using universal primers and sequenced via high-throughput sequencing technology. Microbial community composition and diversity indices were analyzed using QIIME software, while linear discriminant analysis effect size (LEfSe) was employed to identify statistically significant microbial biomarkers between the two groups.Results　A total of 1 618 804 high quality 16S rRNA sequences were obtained from the gut microbiota samples of 20 C57BL/6 mice. At the phylum level, Bacteroidetes and Firmicutes were the dominant taxa with relatively high abundance in both  groups. Alpha diversity analysis revealed no significant differences between the two groups in any of the five indices measured: Observed features, Chao1, Shannon, Simpson, and Good's coverage. However, beta diversity analysis indicated a statistically significant separation in microbial community structure between the aged group and the control group (P<0.05). LEfSe analysis revealed that bacteria from the class Coriobacteriia, order Coriobacteriales, family Eggerthellaceae, and genus Enterorhabdus were identified as significant biomarkers in the gut microbiota of the aged group mice. In contrast, bacteria belonging to the order of Clostridia-UCG-014, family Rikenellaceae, and genus Alistipes were significantly enriched in the gut microbiota of the control group mice.Conclusion　This study characterized the composition and abundance of the gut microbiota in rectal contents of retired aged C57BL/6 mice using 16S rRNA high-throughput sequencing. These findings provide fundamental data for understanding the biological characteristics of retired aged C57BL/6 mice and offer valuable reference information for the selection of appropriate animal models in aging-related research.

Key words: aging, C57BL/6 mice, gut microbiota, 16S rRNA high-throughput sequencing