CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

330

HIV, Not Integrase Inhibitor-Based ART, Modifies Gut Microbiota Composition in MSM Marta Rosas Cancio-Suárez, Luis Miguel Nieto-Salas, Claudio Díaz-García, Jorge Díaz- Álvarez, Alejandro G. García-Ruiz De Morales, Clara Crespillo Andujar, Laura Luna Garcia, Elena Moreno, Laura Martín-Pedraza, Maria Fons, Javier Martínez-Sanz, Raquel Ron, Santiago Moreno, Matilde Sánchez-Conde, Sergio Serrano-Villar Hospital Ramón y Cajal, Madrid, Spain Background: Understanding gut microbiota variations in HIV is confounded by factors like antiretroviral therapy (ART), immune status, and sexual orientation. We aimed to isolate the impact of integrase inhibitor (INSTI)-based ART on gut microbiota among men who have sex with men (MSM) across varying conditions of HIV status and immune recovery. Methods: We conducted an observational study with three cohorts: 1) MSM HIV-negative (HIV-) initiating post-exposure prophylaxis (PEP) with raltegravir, tenofovir disoproxil fumarate, and emtricitabine, sampled on days 0 and 28. 2) MSM with advanced HIV (HIV+ <350 CD4+ T-cells), sampled before and 48 weeks after starting INSTI-based ART. 3) MSM with HIV and adequate immune recovery (HIV+ >500 CD4) after an average of 9.5 years on ART. Stool samples were processed for DNA extraction, sequenced for the V3-V4 regions of the 16S rDNA gene using the Illumina platform and analyzed through the QIIME2 workflow. DADA2 was used to infer Amplicon Sequence Variants, which were assigned to taxonomic entities up to the genera level with a Silva-based 16S Naive Bayes classifier. Differential abundance testing to identify specific taxa was executed with ANCOM. Results: We included 22 MSM HIV-, 23 MSM HIV+ <350 CD4, and 29 MSM HIV+ >500 CD4 participants. Pairwise comparisons were performed to delineate the effects of ART, HIV status, and immune function on microbiota composition. Alpha diversity varied significantly between specific groups (Figure 1A), with highest values in HIV- MSM compared to HIV+ MSM. Weighted UniFrac analysis also demonstrated microbial composition differences between MSM with and without HIV (Figure 1B). Lachnoclostridium genera was more abundant in MSM HIV+ < 350 CD4 (p = 0.0017). Alloprevotella was significantly higher in MSM HIV+ <350 CD4 before ART (p=0.0002) than in MSM HIV-. ART itself showed no significant impact on microbiota composition across all cohorts. Conclusion: In this study not confounded by sexual orientation, HIV and immune status significantly affected gut microbiota composition. However, we found no evidence to suggest that INSTI-based ART negatively influences gut microbiota composition.

331

Microbe-Drug Interactions Between Antiretrovirals and the Gut Microbiome in HIV Infection Christopher Basting , Ty Schroeder, Adrian Velez, Courtney A. Broedlow, Timothy Griffin, Candace Guerrero, Nichole R. Klatt University of Minnesota, Minneapolis, MN, USA Background: For people living with HIV (PLWH), antiretroviral therapy (ART) typically controls HIV replication and greatly reduces mortality, however, does not cure HIV and PLWH must maintain ART treatment inevitably. During passage through the GI tract, ARVs encounter the gut microbiome, where they may affect the growth of microbes or potentially be metabolically transformed by bacteria into less active or toxic forms. Here, we investigated the antimicrobial effects of 17 different ARVs and their in vitro ability to alter microbes to better understand how ART may impact the gut microbiome in PLWH. Furthermore, we investigated the ability of gut bacteria to metabolize ARVs to understand if the gut microbiome may play a role in bioavailability of ARVS. Methods: Bacterial isolates and stool communities were grown from glycerol stock and diluted into fresh media containing the selected ARVs. Growth of bacterial isolates was monitored by measuring the OD600 every 30 minutes for 48 hours. Changes in the bacterial stool communities was determined by 16S V4 rRNA sequencing after 24 hours of incubation with ARVs. ARV drug metabolism by bacterial isolates and whole stool communities was determined by measuring drug concentrations by LC-MS/MS utilizing a novel assay developed in our lab to concurrently measure 17 ARVs. Results: ARVs, especially the integrase inhibitors dolutegravir and elvitegravir, significantly inhibit the growth of gut bacteria including Bacteroides fragilis and Prevotella stercorea (p < 0.05, Welch's t-test). The total bacterial load of in vitro stool cultures measured by the 16S region was significantly different between drug treatments (p < 0.05, Kruskal-Wallis). Furthermore, bacterial stool communities from HIV-infected individuals significantly depleted tenofovir disoproxil fumarate (p = 0.005, Welch's t-test) and cultures with bacterial isolates including Bacteroides fragilis depleted elvitegravir and cobicistat (p = 0.0102 and p = 0.0108 respectively, Welch's t-test). Conclusion: Overall, these results show that specific ARVs can inhibit the growth of strains of gut bacteria and have an impact on a bacterial community's composition in vitro. This has potential implications in how ART affects the gut microbiome of PLWH and associated microbial metabolic products, which is under further study in the lab. Finally, bacterial communities from stool have the metabolic potential to deplete specific ARVs in vitro, which may be important in the interindividual success of ART for PLWH. Gut-Microbiome Changes Over 4 Years in PLWH With Good Immune Status on ART Aya Ishizaka , Michiko Koga, Taketoshi Mizutani, Hiroshi Yotsuyanagi University of Tokyo, Tokyo, Japan Background: The gut microbiota of PLWH who have achieved good immune recovery through ART is as diverse as that of healthy individuals, but the composition of the bacterial taxa is significantly different, which is indicated to be related to chronic inflammation. We evaluated the correlation between changes in the gut microbiota, clinical information, and inflammation biomarkers in PLWH between baseline and after 4 years of follow-up. Methods: Stool and blood samples, along with the laboratory parameters, were collected from 46 PLWH at baseline and after 4 years of follow-up. The microbiome was characterized by sequencing of the 16S rRNA V3- V4 regions on the Illumina MiSeq platform, and data were analyzed using QIIME2 software. Functional gene predictions of the bacterial microbiota were inferred from the 16S rRNA using PICRUSt2 pipeline. The concentrations of cytokine and LPS-binding protein (LBP) were quantified using a Bio-Plex System and ELISA, respectively. Results: There were no significant changes in laboratory parameters between baseline and follow-up except for body mass index (BMI). However, the progression of gut dysbiosis was observed; Lachnospiraceae, involved in short-chain fatty acid (SCFA) production, decreased, while Enterobacteriaceae, potentially pathogenetic bacteria, increased. A decrease in vitamin B1 (thiamine) biosynthesis was predicted from 4-year alternations, suggesting an intestinal environment that is less conducive for SCFA-producing bacteria to proliferate. Higher levels in IL- 27, IFN-β (an LPS/TLR4-inducible cytokine) and IL-8 at follow-up suggested the progression of intestinal permeability while HIV RNA remained low on ART. These cytokines were positively correlated with the bacterial translocation measured by plasma LBP. An increased

Poster Abstracts

332

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CROI 2024