Tongue microbiome of smokeless tobacco users

BMC Microbiol. 2020 Jul 8;20(1):201. doi: 10.1186/s12866-020-01883-8.

Abstract

Background: The possibility that smokeless tobacco may contribute to oral carcinogenesis by influencing the oral microbiome has not been explored. This preliminary cross-sectional study sought to assess the effect of using shammah, a form of smokeless tobacco prevalent in Arabia, on the tongue microbiome. Tongue scarping samples were obtained from 29 shammah users (SU; 27.34 ± 6.9 years) and 23 shammah non-users (SNU; 27.7 ± 7.19 years) and analyzed with 16S rRNA gene sequencing (V1-V3). Species-level taxonomy assignment of the high-quality, merged reads was obtained using a previously described BLASTn-based algorithm. Downstream analyses were performed with QIIME, LEfSe, and R.

Results: A total of 178 species, belonging to 62 genera and 8 phyla were identified. Genera Streptococcus, Leptotrichia, Actinomyces, Veillonella, Haemophilus, Prevotella and Neisseria accounted for more than 60% of the average microbiome. There were no differences between the two groups in species richness and alpha-diversity, but PCoA showed significant separation (P = 0.015, ANOSIM). LEfSe analysis identified 22 species to be differentially abundant between the SU and SNU. However, only 7 species maintained a false discovery rate of ≤0.2 and could cluster the two groups separately: Rothia mucilaginosa, Streptococcus sp. oral taxon 66, Actinomyces meyeri, Streptococcus vestibularis Streptococcus sanguinis and a potentially novel Veillonella species in association with SU, and Oribacterium asaccharolyticum with SNU.

Conclusion: These preliminary results indicate that shammah use induces tongue microbiome changes including enrichment of several species with high acetaldehyde production potential, which warrants further investigation.

Keywords: Microbiota; Mouth neoplasms; Rothia mucilaginosa, high-throughput nucleotide sequencing; Tobacco; Tongue.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bacteria / classification*
  • Bacteria / drug effects
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Case-Control Studies
  • Cross-Sectional Studies
  • DNA, Bacterial / genetics
  • DNA, Ribosomal / genetics
  • Humans
  • Male
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics*
  • Sequence Analysis, DNA
  • Tobacco, Smokeless / adverse effects*
  • Tongue / microbiology*
  • Young Adult

Substances

  • DNA, Bacterial
  • DNA, Ribosomal
  • RNA, Ribosomal, 16S