<em>Lactiplantibacillus</em> <em>plantarum</em> FXJKS21M3 alleviates polycystic ovary syndrome by modulating gut microbiota, serum metabolome and facilitating progestational hormone biosynthesis

The abundance of <em>Lactiplantibacillus plantarum</em> species was found to be decreased in polycystic ovary syndrome (PCOS) patients, indicating this species may play a superior role in PCOS treatment. Here, the potential of six <em>Lp. plantarum</em> strains in reducing PCOS symptoms was assessed in a rat model. <em>Lp. plantarum</em> FXJKS21M3 (F21M3) intervention alleviated abnormal ovarian morphology and restored progesterone and luteinizing hormone levels in rats. Butyrate was not involved in this curative effect on PCOS symptoms. Dysbiosis of specific gut microbes, including <em>Prevotellaceae_Ga6A1_group</em>, <em>Candidatus_Saccharimonas</em>, and <em>ASF356</em>,<em> </em>was restored by <em>Lp. plantarum</em> F21M3 intervention. Enrichment of <em>Bifidobacterium</em> was also observed in <em>Lp. plantarum</em> F21M3-treated rats. The impact of <em>Lp. plantarum</em> F21M3 on the serum metabolome was more remarkable than that on the fecal metabolome. According to enrichment analysis of differential metabolites, the progestational hormone biosynthesis pathway was enriched after <em>Lp. plantarum</em> F21M3 administration. These results demonstrated that <em>Lp. plantarum </em>species may alleviate PCOS symptoms by regulating gut microbiota and facilitating progestational hormone biosynthesis.