New study finds ‘silent’ cervical infection linked with altered immune response

Mumbai: While the gut microbiome is becoming a familiar term for many, further understanding of the microbiome of the cervix is only now coming into focus.In a freshly published study of 43 healthy women at Mumbai's ICMR-NIRRCH, scientists discovered that "silent" infections are secretly rewriting the body's immune environment, undermining the protective power of the "good bacteria" naturally found there.
Between 2021 and 2023, researchers mapped the cervical microbiome of sexually active, non-pregnant women (ages 18-45) using advanced genetic sequencing. This was the first in the Indian context, as this microbiome could change based on demographic and ethnic factors.Though all participants appeared perfectly healthy, laboratory results told a different story. The study, published in the Indian Journal of Clinical Microbiology, found that 32.55% of the women had asymptomatic bacterial vaginosis (BV) and 16.27% had silent yeast (Candida) infections, with 13.95% harbouring both simultaneously."Our earlier studies looked at the vaginal microbiome; this study goes a step further," said lead author Dr Deepti Tandon, a gynaecologist and researcher at the ICMR-NIRRCH department of clinical research.The team found that the cervical environment was dominated by Lactobacillus iners (45.69%). These play a vital role in women's health and immune response to a range of cervical and reproductive issues.However, when silent infections move in, they trigger a "chemical alarm" in the body by raising pro-inflammatory markers, forcing the immune system into a state of high alert and disrupting the delicate balance that keeps the cervix healthy.Co-lead of the study Dr Vikrant Bhor, from the department of molecular immunology and microbiology, said that in women who carried asymptomatic infections, the abundance of Lactobacillus iners was reduced. "These variations were never mapped in our population."He added that, as of now, it is difficult to say if the same findings apply to women who did not have childbirth. "It could be the same case, it could be different. But essentially, in our study, we were able to map the signatures of each of these asymptomatic infections. And we correlated inflammation, which is a hallmark of immunity and infection status, with the presence of different Lactobacillus species," said Dr Bhor.The scientists said these findings will now open doors to a wide range of diagnostic tools in the near future.