Impact of antiretroviral therapy on oral health and oral microbiome of domestic cats with Feline Immunodeficiency Virus

Feline immunodeficiency virus (FIV) is the domestic cat analogue of HIV infection in humans. Both viruses induce oral disease in untreated individuals, with clinical signs that include gingivitis and periodontal lesions. Oral disease manifestations in HIV-patients are abated by highly effective combination antiretroviral therapy (cART), though certain oral manifestations persist despite therapy. Microorganisms associated with oral cavity opportunistic infections in patients with HIV cause similar pathologies in cats. To further characterize this model, we evaluated characteristics of the feline oral health and oral microbiome during FIV infection in control versus FIV-infected cats treated with cART or placebo. Gingival biopsies were collected at four timepoints and assessed with a 16S metagenomics sequencing approach and comprehensive oral examinations were conducted by a veterinary dental specialist over an 8-month period. Gingival inflammation was increased in FIV-infected cats treated with placebo compared to cART treated cats and controls at study endpoint. Oral microbiome alpha diversity increased across all cats, but beta diversity differed among treatment groups, documenting a significant effect of cART therapy on microbiome community composition. This finding has not previously been reported and indicates cART ameliorates immunodeficiency virus-associated oral disease via preservation of oral mucosal microbiota. This study illustrates the value of the FIV animal model for investigations of mechanistic associations and therapeutic interventions for HIV oral manifestations.