Clinical and Oral Microbiome Shifts in HIV+ Following Comprehesive Dental Care

Objectives: The microbiome may exert significant effects in the context of immunosuppression. The objective of this study was to compare clinical outcomes and microbiome changes following comprehensive dental care in HIV+ patients.
Methods: Ten HIV+ patients received periodontal treatment, oral hygiene instructions, caries control, and extraction of hopeless teeth. Systemic (viral load (VL), CD4 counts, ART regimen) and oral clinical parameters (caries, gingival and plaque indices) were assesed at baseline (BL) and 12 mo. Periodontal disease severity was determined using the biofilm-gingival interface (BGI) index. Salivary microbial content was sequenced the 16S rDNA gene V1-V3 hypervariable region using MiSeq (Illumina, CA) and reads were evaluated using QIIME.
Results: Subjects were mostly male (80%), African American (80%) and were on ART (80%). At BL, BGI of 3 (40%) and 4 (60%) were found and 50% of patients had undetectable VL. At 12M, 3 patients showed decreased VL and 2 had increased VL. BGI improved in 5 patients and remained unchanged in 2. OTU abundance was determined in paired samples (pre and post treatment) and were associated with changes in clinical correlates. The most significant OTU differences were detected in the Actinobacteria, Proteobacteria and Firmicutes taxa. Those demonstrating the greatest microbiome differences with the intervention had higher HIV viral loads at baseline. Overall, the relative abundance of taxa typically associated with periodontal disease and inflammation were decreased after therapy, including Tannerella (mean %reduction±SD; 0.03%±0.1%), Prevotella (2.64%±3.3%), Filifactor (0.09%±0.2%), Parvimonas (0.49%±0.5%), Fusobacterium (0.19%±1%) and Treponema (0.04%±0.1%). Conversely, increased levels of host-compatible genera were observed, such as Actinomyces (0.44%±6.5%), Streptococcus (0.6% ±12%), Neisseria (0.29% ±8.6%) and Veillonella (1.58%±4.1%). One subject with BGI=4 throughout the study had increased VL and presented higher levels of Porphyromonas (by 8.13%), Tannerella (0.03%), Parvimonas (0.01%) and reduced levels of Veillonella (by 2.57%) at 12M.
Conclusions: Periodontal treatment in HIV+ patients promoted a reduction in levels of pathogenic microbiota and the establishment of a community conducive to clinical improvement.