AUTHOR=Kalanzi Dunstan , Mayanja-Kizza Harriet , Nakanjako Damalie , Semitala Fred , Mboowa Gerald , Mbabali Muhammad , Kigozi Edgar , Katabazi Fred Ashaba , Sserwadda Ivan , Kateete David P. , Achan Beatrice , Sewankambo Nelson K. , Muwonge Adrian 

TITLE=Microbial characteristics of dental caries in HIV positive individuals

JOURNAL=Frontiers in Oral Health

VOLUME=Volume 3 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/oral-health/articles/10.3389/froh.2022.1004930

DOI=10.3389/froh.2022.1004930

ISSN=2673-4842

ABSTRACT=Background: Dental caries is a multifactorial disease that affects many people. Even though microorganisms play a crucial role in causing dental caries, diagnosis is routinely macroscopic. In order to improve early detection especially in HIV patients who are disproportionately affected, there is need to reconcile the macroscopic and microscopic characteristics of dental caries. Therefore, the aim of this study was to characterize oral microbiota changes along the decayed, missing, filled teeth (DMFT) index using amplicon sequencing data.
Methods: Amplicon sequencing of the V6-V8 region of the 16S rRNA gene was done on DNA recovered from whole unstimulated saliva of 59 HIV positive and 29 HIV negative individuals. The microbial structure, composition and co-occurrence networks were characterized using QIIME-2, Phyloseq, Microbiome-1.9.2 and Metacoder in R.
Results: We characterized the oral microbiota into 2,093 operational taxonomic units (OTUs), 21 phyla and 239 genera from 2.6 million high quality sequence reads. While oral microbiota did not cluster participants into distinct groups that track with the DMFT index, we observed the following: a) A steady increase in accessory microbiota while the core size (~50% of richness) remained stable. b) The abundance of core genera such as Stomatobaculum, Peptostreptococcus and Campylobacter increased at onset of dental caries, c) A general increase in oral microbial biomass. d) The onset of dental caries (low DMFT) was associated with massive reduction in oral microbial entropy. 
Conclusions: Although oral microbial shifts along the DMFT index are not distinct, we have demonstrated the potential utility of microbiota dynamics to inform oral disease characteristics. Therefore, we propose a microbial framework characterizing DMFT to better understand dental caries among HIV positive persons in resource limited settings.