Probiotics may improve vaginal microbiota, metabolic disorders and ovarian function-related markers by modulating gut microbiota in POI mice.

backgroundPremature ovarian insufficiency (POI) is a condition identified by the decline in ovarian function before the age of 40. The treatment of POI patients deserves in-depth research. This study aimed to explore the impacts of probiotics on the gut and vaginal microbiota, ovarian function and metabolic indexes in a mouse model of POI.

methodsA mouse model of POI was successfully established by intraperitoneal injection of cyclophosphamide. Subsequently, the mice were divided into the control group, the POI group and the POI gavage group. Mice in the POI gavage group were gavaged for 28 consecutive days with a mixture of 12 probiotics. The anti-Müllerian hormone (AMH) and sex hormone levels, the number of follicles, the serum total cholesterol (TC) and triglycerides (TG) levels and the distributions of gut and vaginal microbiota of the mice were assessed and compared.

resultsCompared with the healthy control group, the level of AMH and the number of growing follicles significantly decreased in POI mice (P<0.05), whereas the number of atretic follicles increased significantly (P<0.05). Meanwhile, the gut and vaginal microbiotas were disturbed in the POI group. Bacterial genera such as Allobaculum, Prevotella and Bacteroides were enriched in the gut microbiota, while Proteus, Streptococcus and Rothia were enriched in the vaginal microbiota. However, these bacteria contributed no favorable effect on the host. Interestingly, the increases in these taxa were reversed in POI mice treated with probiotics. Additionally, although there were no significant differences in AMH, estradiol (E2), and follicle stimulating hormone (FSH) levels between POI group without probiotics and POI gavage group (P>0.05), the AMH and E2 levels tended to increase while the FSH level tended to decrease in the gavage group. Besides, the number of growing follicles in the gavage group exhibited a slight increase compared with the POI group without probiotics (P>0.05), whereas the number of atretic follicles in the gavage group showed a decrease (P>0.05). Moreover, the levels of TC and TG in POI group without probiotics were elevated compared with the control group, while this trend was reversed in the POI gavage group (TG: P<0.05, TC: P>0.05).

conclusionsProbiotics may mitigate vaginal microbiota disruption, alleviate lipid metabolism disorders and improve indicators related to ovarian function by modulating the dysbiosis of gut microbiota in POI mice. These results provide some new directions and theoretical foundations for future microecological treatment in POI patients in clinical practice.