Effect of HIV/HAART and Other Clinical Variables on the Oral Mycobiome Using Multivariate Analyses.

The oral microbiome is considered an important factor in health and disease. We recently reported significant effects of HIV and several other clinical variables on the oral bacterial communities in a large cohort of HIV-positive and -negative individuals. The purpose of the present study was to similarly analyze the oral mycobiome in the same cohort. To identify fungi, the internal transcribed spacer 2 (ITS2) of the fungal rRNA genes was sequenced using oral rinse samples from 149 HIV-positive and 88 HIV-negative subjects that had previously undergone bacterial amplicon sequencing. Quantitative PCR was performed for total fungal content and total bacterial content. Interestingly, samples often showed predominance of a single fungal species with four major clusters predominated by , , , or Quantitative PCR analysis showed the -dominated sample clusters had significantly higher total fungal abundance than the or species. Of the 25 clinical variables evaluated for potential influences on the oral mycobiome, significant effects were associated with caries status, geographical site of sampling, sex, HIV under highly active antiretroviral therapy (HAART), and missing teeth, in rank order of statistical significance. Investigating specific interactions between fungi and bacteria in the samples often showed species positively correlated with or and negatively correlated with , , and Our data suggest that the oral mycobiome, while diverse, is often dominated by a limited number of species per individual; is affected by several clinical variables, including HIV positivity and HAART; and shows genera-specific associations with bacterial groups. The oral microbiome is likely a key element of homeostasis in the oral cavity. With >600 bacterial species and >160 fungal species comprising the oral microbiome, influences on its composition can have an impact on both local and systemic health. We recently reported significant effects of HIV and several other clinical variables on the oral bacterial community in a large cohort of HIV-positive and -negative subjects. We describe here a comprehensive analysis of the oral mycobiome in the same cohort. Similar to the bacterial community, HIV under highly active antiretroviral therapy (HAART) had a significant impact on the mycobiome composition, but with less impact compared to other clinical variables. Additionally, unlike the oral bacterial microbiome, the oral mycobiome is often dominated by a single species with 4 major clusters of fungal communities. Together, these results suggest the oral mycobiome has distinct properties compared with the oral bacterial community, although both are equally impacted by HIV.