Improvement of vaginal probiotics Lactobacillus crispatus on intrauterine adhesion in mice model and in clinical practice

Background: Intrauterine adhesion (IUA) is a frequent acquired endometrial condition, for which there is no effective preventive or treatment. Previous studies have found that vaginal microbiota dysregulation is closely related to endometrial fibrosis and IUA. Results In this study, we administered Lactobacillus crispatus ( L. crispatus ) vaginally to restore vaginal microbiota and explore the beneficial role of vaginal probiotics in the treatment and prevention of IUA. Then, we created a mechanically injured mouse model of IUA and restored the mice's vaginal microbiota by the addition of L. crispatus convolvulus. The observations suggested that intrauterine injections of L. crispatus significantly decreased the degree of uterine fibrosis, the levels of IL-1β and TNF-α in blood, and downregulated the TGF-β1/SMADs signaling pathway in IUA mice. A therapy with L. crispatus considerably raised the abundance of the helpful bacteria Lactobacillus and Oscillospira and restored the balance of the vaginal microbiota in IUA mice, according to high-throughput sequencing. Then we conducted a randomized controlled trial to compare the therapeutic effect of L. crispatus with estrogen after TCRA. And the results showed that vaginal probiotics had a better potential to prevent intrauterine adhesion than estrogen. Conclusions This study confirmed that the prevention and treatment of L. crispatus in IUA has a certain effect, and made a new exploration for the treatment of vaginal probiotics in gynecological diseases. Clinical trial registration : http://www.chictr.org.cn/, identifier (ChiCTR1900022522), registration time: 15/04/2019.