Cervical cancer-related shifts from a Lactobacillus-dominant to a polymicrobial cervical microbiome

The cervical microbiome (CM) is a complex ecosystem that can change in response to gynecological cancers. To evaluate changes in the CM of patients who underwent chemoradiation (CRT) therapy for locally advanced cervical cancer. Before and after CRT, cervical swab samples were collected from 16 patients with squamous cell carcinoma of the cervix, and from 16 healthy women. All samples were subjected to 16sRNA-Seq analysis. The CM in healthy women comprised mostly Lactobacillus (>90%). The CM community in samples from pre-treatment cancer patients was heterogeneous, with a low proportion of Lactobacillus. On the phylum level, Cyanobacteria and Firmicutes significantly differentiated healthy controls from pre-treatment samples, as did 13 taxa on the genus level (including Lactobacillus, Peptostreptococcus, and Anaerococcus). On the phylum level, Cyanobacteria, Fusobacteriota, and Bacteroidota significantly differentiated pre- and post-radiation samples, as did 40 taxa on the genus level. Microbiome diversity was significantly higher in pre-treatment patients than in healthy controls, whereas microbiome richness was significantly higher in post- than in pre-treatment samples; however, this was not the case 3 or 6 months later. The results reveal marked significant alterations in the CM of cervical cancer patients relative to that in healthy controls; these changes were more striking after CRT. However, further research is needed to determine whether alteration of the CM offers new therapeutic options.