Pre and Post Seroconversion Gut Microbiome Analysis in HIV-infected individuals

Abstract: Intensive research on human immunodeficiency virus (HIV) is being conducted in efforts to understand HIV pathogenesis. In the past decade, the development of innovative bioinformatics technology has focused research on the human gut microbiome and its potential role in the pathogenesis of HIV. Recent research has shown that gut microbial imbalance, or dysbiosis, may lead to microbial translocation and chronic inflammation in HIV-infected individuals, further enhancing HIV progression, potentially towards the development of AIDS. Gut microbiota in untreated men who have sex with men (MSM) with HIV can have an over-representation of pro-inflammatory Proteobacteria, associated with mucosal and systemic immune activation. Our research aims to investigate the gut microbiome of 16 untreated HIV-infected men who have sex with men (MSM) at time-points that are ~6 months pre-seroconversion and ~6 months post-seroconversion to assess bacterial changes that may make individuals more susceptible to the development of AIDS, using Multicenter AIDS Cohort Study (MACS) fecal samples from 1984-1985. Using high throughput sequencing technology, bacterial 16s rRNA genes were amplified, sequenced, and then clustered into operational taxonomic units using QIIME software.   Results showed that fecal samples from both non-HIV infected controls and HIV-infected MSM in 1984-85 had dominant taxa from the phyla Firmicutes, Bacteroidetes and Proteobacteria. Both visits non-infected controls showed a relative abundance of Firmicutes (35.3%), Bacteroidetes (56%) and Proteobacteria (5.53%); similarly, both visits seroconverters showed a relative abundance of Firmicutes (38.3%) Bacteroidetes (53.2%), and Proteobacteria (4.5%). Genera level abundance of seroconverters (SC) both visits vs non-HIV infected controls both visits showed an increase in Prevotella (51.2% SC; 38% controls) and a decrease in Bacteroides (14.1% SC; 27.11% controls). Alpha diversity and beta diversity are currently being analyzed for statistical significance.