Affiliations 

  • 1 Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital, Street 34 Hospital Rd, Sai Ying Pun, Hong Kong, SAR, China
  • 2 School of Pharmacy, Monash University Malaysia, Subang Jaya, Malaysia
  • 3 Human Molecular Genetics Lab, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India
  • 4 Saveetha Dental College and Hospital, Saveetha University, Chennai, India
  • 5 Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital, Street 34 Hospital Rd, Sai Ying Pun, Hong Kong, SAR, China. botelho@hku.hk
  • 6 Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital, Street 34 Hospital Rd, Sai Ying Pun, Hong Kong, SAR, China. n.johnson@griffith.edu.au
Clin Oral Investig, 2022 Feb;26(2):1647-1656.
PMID: 34436669 DOI: 10.1007/s00784-021-04137-7

Abstract

INTRODUCTION: Smoked, and especially smokeless, tobacco are major causes of oral cancer globally. Here, we examine the oral bacteriome of smokers and of smokeless tobacco users, in comparison to healthy controls, using 16S rRNA gene sequencing.

METHODS: Oral swab samples were collected from smokers, smokeless tobacco users, and healthy controls (n = 44). Microbial DNA was extracted and the 16S rRNA gene profiled using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and taxonomical classification was performed using the phylogenetic placement method. Differentially abundant taxa were identified using DESeq2, while functional metagenomes based on KEGG orthology abundance were inferred using LIMMA.

RESULTS: A significantly higher microbial diversity was observed in smokeless tobacco users and smokers relative to controls (P  1.5; BH adj P 

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.