Microbiota and Pelvic Inflammatory Disease Original paper

What was reviewed?

This review examined the complex relationship between pelvic inflammatory disease (PID) and the genital microbiota. It focused on recent advancements in molecular microbiological techniques and their implications for understanding the diverse bacterial communities in both healthy and diseased states of the female genital tract. It also explored how changes in these microbial communities (dysbiosis), specifically bacterial vaginosis, could significantly increase the risk of PID, sexually transmitted infections (STIs), HIV, and adverse reproductive outcomes.

Who was reviewed?

The review analyzed findings from several clinical and molecular microbiology studies involving women diagnosed with pelvic inflammatory disease or other genital infections. It included detailed analyses of microbial communities identified through culture-based methods and advanced molecular techniques, such as 16S rRNA sequencing, PCR-based identification, and cloning and sequencing methods. Patient groups ranged from asymptomatic healthy individuals to women with symptomatic PID, endometriosis, salpingitis, and tubo-ovarian abscesses (TOAs).

What were the most important findings?

The most important findings were that PID is typically polymicrobial, involving a diverse range of pathogens beyond traditional culprits like Chlamydia trachomatis and Neisseria gonorrhoeae. Advanced molecular techniques revealed that bacterial vaginosis-associated bacteria (BVAB), including Gardnerella vaginalis, Atopobium vaginae, and several anaerobic species (e.g., Prevotella, Sneathia, and BVAB 1, 2, and 3), significantly associate with PID development. This contrasts with earlier beliefs that focused primarily on classic sexually transmitted pathogens. The data strongly indicate that vaginal microbiota disturbances, especially reductions in protective Lactobacillus species, substantially increase the risk of ascending infections to the upper genital tract.

Clinicians are increasingly recognizing novel microbial phylotypes and traditionally overlooked anaerobes in PID, especially in severe cases like TOAs. Anaerobes such as Prevotella, Bacteroides, and Peptostreptococcus have frequently emerged as critical players. The identification of BV-associated microbes in salpingitis and abscesses reinforces the microbial continuum from vaginal dysbiosis to upper genital tract infections, providing substantial evidence that microbial dysbiosis directly predisposes women to PID.

What are the greatest implications of this review?

This review significantly impacts clinical practice by underscoring the importance of maintaining a healthy vaginal microbiota to prevent upper genital tract infections. Clinicians should recognize BV as a critical modifiable risk factor for PID and associated complications, including infertility and ectopic pregnancy. The findings emphasize the urgent need for improved screening and treatment strategies for BV to reduce PID incidence and associated reproductive health complications. Additionally, molecular identification of novel pathogens stresses the necessity of broad-spectrum antimicrobial regimens capable of targeting a diverse microbial landscape, especially anaerobes. Future research must continue exploring the therapeutic and preventive potential of maintaining a healthy vaginal microbiome.