Objective  It is still unclear whether miR-146a, as an anti-inflammatory factor, is involved in the interaction between host and microbes, and then affects intestinal homeostasis. Therefore, this study aims to investigate the effect of miR-146a on the intestinal flora of mice.

Method  Intestinal miR-146a-specific knockout mice (CKO mice) and control mice (Flox mice) were used as research subjects, and the 16S rRNA high-throughput sequencing method was used to detect the distribution of microflora in the jejunum of the two groups.

Result  Through sequencing, we obtained a total of 1 134 OTUs for species classification, including 37 phyla, 80 classes, 161 orders, 198 families, 261 genera and 117 species of bacteria. There were a total of 46 identical OTUs in the jejunal microbes of the Flox group and CKO group. Firmicutes, Bacteroidota, Verrucomicrobiota, Proteobacteria and Desulfobacterota were the dominant bacteria in gut microbes of each group. The gut microbial community compositions of the two groups were generally similar, while the average abundance of Clostridia in the CKO group was higher than that in the Flox group (P=0.067), and the average abundance of Lachnospirales in the CKO group was significantly higher than that in the Flox group (P<0.05). There was no significant difference in the composition of other levels.

Conclusion  Knockout of miR-146a can alter the contents of Clostridia and Lachnospirales microorganisms in the host gut, which provides a reference for studying how miR-146a affects gut health by altering host gut microbes.