Bacteriome and mycobiome associations in oral tongue cancer

Abstract

Squamous cell carcinoma of the oral (mobile) tongue (OMTC), a non-human papilloma virus-associated oral cancer, is rapidly increasing without clear etiology. Poor oral hygiene has been associated with oral cancers, suggesting that oral bacteriome (bacterial community) and mycobiome (fungal community) could play a role. While the bacteriome is increasingly recognized as an active participant in health, the role of the mycobiome has not been studied in OMTC. Tissue DNA was extracted from 39 paired tumor and adjacent normal tissues from patients with OMTC. Microbiome profiling, principal coordinate, and dissimilarity index analyses showed bacterial diversity and richness, and fungal richness, were significantly reduced in tumor tissue (TT) compared to their matched non-tumor tissues (NTT, P<0.006). Firmicutes was the most abundant bacterial phylum, which was significantly increased in TT compared to NTT (48% vs. 40%, respectively; P=0.004). Abundance of Bacteroidetes and Fusobacteria were significantly decreased in TT compared to matched NTT (P≤0.003 for both). Abundance of 22 bacterial and 7 fungal genera was significantly different between the TT and NTT, including Streptococcus, which was the most abundant and significantly increased in the tumor group (34% vs. 22%, P<0.001). Abundance of fungal genus Aspergillus in TT correlated negatively with bacteria (Actinomyces, Prevotella, Streptococcus), but positively with Aggregatibacter. Patients with high T-stage disease had lower mean differences between TT and NTT compared with patients with low T-stage disease (0.07 vs. 0.21, P=0.04). Our results demonstrate differences in bacteriome and mycobiome between OMTC and their matched normal oral epithelium, and their association with T-stage.

World Workshop on Oral Medicine VII: Targeting the oral microbiome Part 2: Current knowledge on malignant and potentially malignant oral disorders

“…() and Mukherjee et al. () found that Streptococcus was significantly enriched in OSCC, whereas Al‐Hebshi et al. () found this genus to be significantly enriched in the controls.…”

“…Twenty‐three non‐specific sequence‐based identification studies of the microbiota were included, 14 of which were published in 2017–2018 (Table ) (Al‐Hebshi, Nasher, Idris, & Chen, ; Al‐Hebshi et al., ; Bebek et al., ; Börnigen et al., ; Guerrero‐Preston et al., , ; Hayes et al., ; Hooper et al., ; Hu, Zhang, Hua, & Chen, ; Lee et al., ; Li et al., ; Mukherjee et al., ; Perera et al., , ; Pushalkar et al., , ; Schmidt et al., ; Shin et al., ; Wang et al., ; Wolf et al., ;Yang, Huang et al., ; Yang, Yeh et al., ; Zhao et al., ). Twenty‐one studies focused on bacterial identification (all by 16S rRNA gene regions), one of which also identified fungi (ITS2 gene fragment), one only fungi, and one was restricted to viral identification (human rRNA detection followed by search for viral sequences).…”

Streptococcus endopeptidases promote HPV infection in vitro

“…The microbiome findings have been varied. One group reported decrease (Schmidt et al., ), while two other groups reported increase (Guerrero‐Preston et al., ; Mukherjee et al., ) of Streptococcus species in oral cancer lesions in comparison with controls. We think that microbial cancer‐promoting factors might not be limited to specific bacterial species.…”

Fungi at the Scene of the Crime: Innocent Bystanders or Accomplices in Oral Infections?

“…The emergence of these datasets has been the catalyst for a number of studies investigating the importance of fungi within oral biofilm infections. This has fuelled the concept of interkingdom communities, which continues to grow above and beyond our traditional viewpoint of bacterial-bacterial interactions [12][13][14]. Indeed, the advancement in sequencing technologies has facilitated the characterisation of the fungal oral microbiome [11, 15•, 16].…”