Changes in intestinal flora depending on the stage of HIV infection, viral load and CD4-cell count

Abstract

The aim of the work is to establish patterns of changes in the taxonomic composition and functional activity of the intestinal microbiota depending on the clinical stage of HIV infection, the level of viral load and the number of CD4-lymphocytes with the determination of prognostic markers of disease progression. Materials and methods. A prospective cohort study of 347 patients with verified HIV infection and 78 healthy volunteers was conducted from January 2021 to December 2023. Taxonomic analysis of the microbiota was performed by high-throughput sequencing of the variable regions V3–V4 of the 16S rRNA gene on the Illumina MiSeq platform with determination of the viral load by PCR and counting of CD4-lymphocytes by flow cytometry. Results and discussion. A progressive decrease in microbial richness was revealed as HIV infection worsened, with a decrease in the Shannon index from 4.12±0.34 in the control to 1.94±0.29 at the terminal stage. A strong negative correlation was established between microbiota diversity and viral load, and a positive correlation with the number of CD4-cells. The relative representation of Proteobacteria increased from 8.1% to 41.7%, while the proportion of Firmicutes decreased from 68.4% to 34.2% with disease progression. Conclusions. The progression of HIV infection is naturally accompanied by the formation of severe dysbiosis with a critical decrease in microbial diversity at a CD4-cell level of less than 200/μl, which allows the use of microbiological parameters as additional prognostic biomarkers of the disease course.