Immune status, and not HIV infection or exposure, drives the development of the oral microbiota

M O Coker,P Akhigbe,S S El-Kamary,M Charurat,P Langenberg,W A Blattner,C Enwonwu,A Omoigberale,E F Mongodin,O Obuekwe,L Hittle

doi:10.1038/s41598-020-67487-4

Abstract

Even with antiretroviral therapy, children born to HIV-infected (HI) mothers are at a higher risk of early-life infections and morbidities including dental disease. The increased risk of dental caries in HI children suggest immune-mediated changes in oral bacterial communities, however, the impact of perinatal HIV exposure on the oral microbiota remains unclear. We hypothesized that the oral microbiota of HI and perinatally HIV-exposed-but-uninfected (HEU) children will significantly differ from HIV-unexposed-and-uninfected (HUU) children. Saliva samples from 286 child-participants in Nigeria, aged ≤ 6 years, were analyzed using 16S rRNA gene sequencing. Perinatal HIV infection was significantly associated with community composition (HI vs. HUU—p = 0.04; HEU vs. HUU—p = 0.11) however, immune status had stronger impacts on bacterial profiles (p < 0.001). We observed age-stratified associations of perinatal HIV exposure on community composition, with HEU children differing from HUU children in early life but HEU children becoming more similar to HUU children with age. Our findings suggest that, regardless of age, HIV infection or exposure, low CD4 levels persistently alter the oral microbiota during this critical developmental period. Data also indicates that, while HIV infection clearly shapes the developing infant oral microbiome, the effect of perinatal exposure (without infection) appears transient.

Highlights

With the rapid scale up of life-saving antiretroviral therapy (ART)[1] worldwide, there has been a significant reduction in HIV-related deaths in infants and c hildren[2,3]
We and o thers[9,11,12,13] have observed a higher prevalence of dental caries and necrotizing periodontal diseases in children and young adults infected with HIV, while other studies have reported lower caries prevalence and severity compared to the HIV-uninfected individuals[20]
There are some taxonomic differences when comparing salivary microbiota of HI and HIV exposed-uninfected (HEU) children from unexposed and uninfected counterparts (HUU children), and immunosuppression had a more pronounced effect on salivary bacterial composition

Summary

Introduction

With the rapid scale up of life-saving antiretroviral therapy (ART)[1] worldwide, there has been a significant reduction in HIV-related deaths in infants and c hildren[2,3]. In support of the possible association between HIV infection and oral/dental pathologies, ART has been shown to significantly impact the composition of salivary microbiota[21]; there are significant knowledge gaps in describing and explaining the effect of HIV infection or perinatal exposure on salivary microbial composition. This gap further widens with respect to infants and children. We hypothesized that perinatal HIV exposure and infection would compromise the immune system and lead to a disruption in the salivary microbiota composition and subsequently causing a shift that could facilitate disease cariogenesis

Objectives

Methods

Results

Conclusion