HPV infection and bacterial microbiota in the placenta, uterine cervix and oral mucosaOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study asked whether an existing HPV infection is associated with bacterial microbiota composition in the placenta, uterine cervix, and mouth. HPV DNA was genotyped for 24 types using the Multimetrix assay. Bacterial communities were characterized by 16S rRNA gene sequencing. The team compared HPV positive and HPV negative samples at each site. They used LEfSe and diversity metrics (Chao1 richness, Shannon diversity) to detect taxa enriched with HPV. Careful negative controls were run to rule out contamination.
Who was studied?
The sample was 39 pregnant women from the Finnish Family HPV Study, enrolled in their third trimester. Placental, cervical, and oral specimens taken during the last trimester were analyzed. Thirteen placentas carried HPV DNA, matched with HPV negative placentas from vaginal and caesarean deliveries. After filtering low-read placental samples, 19 of 39 placenta samples (49%) entered analysis. This was a human observational study in Finland.
What were the most important findings?
HPV DNA was found in 33% of placental, 23% of cervical, and 33% to 36% of oral samples, with HPV16 most frequent. In the placenta, HPV positivity linked to higher Lactobacillaceae (p = 0.0036) and Ureaplasma (LDA greater than 4.0). In the cervix, Haemophilus (p = 0.00058) and Peptostreptococcus (p = 0.0069) were higher in HPV negative samples. In the mouth, Selenomonas (p = 0.0032) rose with HPV. Oral samples showed significantly higher bacterial richness with HPV (Chao1, p = 0.032). Placental and cervical richness and diversity did not differ by HPV status.
What are the greatest implications of this study?
The results suggest HPV infection is associated with altered bacterial communities in the placenta, cervix, and mouth. The authors present this as among the first evidence linking HPV to placental and oral microbiota. Whether the bacterial shifts predispose to HPV or follow from it remains unknown. The study cannot separate cause from consequence. Only 13 placentas were HPV positive, so overall richness differences may have been missed. Larger studies are needed to confirm the patterns.