Vaginal Lactobacilli can have different impacts on the female reproductive tract based on the bacterial species present

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05367
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38020:Applied microbiology-related
• Research Institution: Kitasato University
• Principal Investigator: Ito Masahiro 北里大学, 薬学部, 助教 (90596727)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 腟常在乳酸桿菌

Outline of Final Research Achievements

This study revealed that Lactobacillus iners negatively affects the barrier function of vaginal epithelial cells, while Lactobacillus crispatus has a positive impact. Recent reports indicate that Lactobacillus iners, the most prevalent vaginal bacteria in approximately 30% of Japanese women, is linked to higher risks of preterm birth, cervical cancer, infertility, and sexually transmitted diseases compared to L. crispatus, which is predominant in about 40% of Japanese women. The differences in their effects on the vaginal mucosal barrier mechanism are believed to contribute to their differing susceptibilities to female reproductive diseases.

Free Research Field

微生物学

Academic Significance and Societal Importance of the Research Achievements

我が国において子宮頸がん、早産、不妊症は年々増加している。これまで遺伝学的・細胞学的解析等ではその原因はわからなかったが、本研究成果によりその要因として腟常在細菌 L. iners による粘膜バリア機構への破綻作用が関与している可能性が考えられた。一方、腟常在細菌 L. crispatus は粘膜バリア機構を亢進させること、またその定着率を高める機構を明らかにできたことから、それらの機構を利用し、腟常在細菌を L. iners から L. crispatus に置き換えるなど、その臨床応用へとつなげることが期待される。