<p>Vaginal Microbiota and HPV Infection: Novel Mechanistic Insights and Therapeutic Strategies</p>

Abstract

Cervical cancer is a global public health concern. The complex interaction of genetic and environmental factors is critical for the progress of cervical cancer. Growing evidence suggests that microbes, human papillomavirus (HPV), and the immune system interact closely with each other to govern homeostasis of the vaginal environment and the health of the lower genital tract of females. Certain vaginal microbial strains may play either a protective or a pathogenic role in carcinogenesis of the cervix after HPV persistent infection. Probiotics can therefore present a putative therapeutic approach for cervical cancer. However, work in this field remains limited. Recent technological developments have allowed us to identify microbes and their products using culture-independent molecular detection techniques. In this review, we discuss the composition of the vaginal bacterial community, its commensal flora and the protective impact this has on the health of the female genital tract. This review will also describe critical immune factors in lower genital tract health and summarize the role of the vaginal microbiota in cervical carcinogenesis. Knowledge in this field has provided researchers with the clues and tools to propose the use of probiotics as a potential line of treatment for cervical cancer and has provided valuable insights into host-pathogen interaction dynamics within the female genital tract.

From Microbiome to Inflammation: The Key Drivers of Cervical Cancer

“…Human papillomavirus is known to be a pivotal factor in the development of cervical cancer. HPV causes various diseases, including cervical cancer and precancerous lesions ( Li et al, 2020 ). HPV is divided into hr-HPV and lr-HPV.…”

“…Probiotics are made up of living bacteria such as Bifidobacterium , Lactobacillus , and Streptococcus . It reduces the risk of certain cancers by regulating the composition of the microbiome and increasing inflammation ( Li et al, 2020 ).…”

Microbiome and Cervical Cancer

“…According to the World Health Organization, probiotics are “live microorganisms which when administered in adequate amounts confer a health benefit on the host” [109]. The species of Bifidobacterium , Lactobacillus , and Streptococcus are capable of altering the host’s microbiome, improving the immune response and the inflammatory state [110].…”

“…Probiotics containing species of lactobacilli have been used in the treatment of urogenital infections to improve the vaginal flora. The mechanism of action would involve vaginal acidification, prevention of bacterial adhesion, and synergistic action with the host’s immune system [110]. Although there are no conclusive data on their efficacy, probiotics seem to be an alternative complementary treatment of BV and sexually transmitted diseases given that they do not induce inflammation, promote resistance, or have adverse effects [111].…”

Probiotic Effects against Virus Infections: New Weapons for an Old War

“…Thus, it was previously identified at least 11 single cases of patients, who after Lactobacillus supplementation suffered invasive Lactobacillus infections, causing symptoms such as bacteremia, pneumonia, or empyema, and even causing one documented death [ 104 ]. The risk of probiotics in immunocompromised people varies based on their contents, being L. rhamnosus the riskiest Lactobacillus species [ 105 ].…”