A study conducted by the Institute for Genetic and Biomedical Research of the National Research Council (CNR‑IRGB), in collaboration with the IRCCS Burlo Garofolo in Trieste, has revealed that healthy Italian women display a vaginal microbiota composition that differs markedly from that of women in Northern Europe. The research, published in mSystems, analysed 61 healthy women of reproductive age within the Women4Health project, recruited from the city of Trieste.
The study shows that Lactobacillus iners is the most abundant and prevalent species in the vaginal microbiota of these Italian women, challenging the commonly held assumption that its presence indicates dysbiosis or poor vaginal health. Despite natural hormonal fluctuations across the menstrual cycle, the microbial community remained largely stable, with significant changes observed only in a minority of participants.
These findings highlight the importance of considering geographical context and hormonal profiles when assessing vaginal microbial health. The reasons behind the differences from Northern European populations—where Lactobacillus crispatus is typically dominant—remain unclear and will be explored in future research, including potential links with conditions such as endometriosis.
The Women4Health study has expanded to additional Italian clinical centres, creating a multicentre network aimed at building a more representative picture of the Italian vaginal microbiota. This effort may support advances in the prevention and personalised diagnosis of conditions such as bacterial vaginosis, infertility and endometriosis. The project also includes the characterisation of the gut microbiome to investigate the gut–vagina axis and its relevance for women’s cardiometabolic health.
The research was supported by the European Research Council (ERC Starting Grant SEMICYCLE), the Italian Ministry of Health, and co‑funded by the Age‑It programme within the National Recovery and Resilience Plan (PNRR).
Original article link: https://journals.asm.org/doi/10.1128/msystems.00983-25
Press release (in Italian only):
OTHER USEFUL LINKS:
https://irgb.cnr.it/erc-starting-grant-2022-awarded-to-serena-sanna-at-the-irgb/
https://irgb.cnr.it/projects/w4h-3/
www.women4health.it (in Italian)