Impact of obesity on the gut microbiome and inflammatory markers during SIV infection and antiretroviral therapyOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined how obesity affects the gut microbiome and biomarkers of microbial translocation (MT) and inflammation during simian immunodeficiency virus (SIV) infection and subsequent antiretroviral therapy (ART). Researchers tracked changes in gut bacterial community composition alongside circulating markers of gut barrier breakdown and immune activation. The work was motivated by the rising rate of obesity among people living with HIV and the shared role of dysbiosis and impaired gut barrier integrity in driving chronic immune activation in both conditions.
Who was studied?
The study used lean and obese rhesus macaques that were experimentally infected with SIV and then treated with ART. This is an animal model of HIV infection rather than a human cohort, allowing controlled comparison of body-weight status on gut and immune outcomes over the course of infection and treatment. The abstract does not give an exact number of animals per group.
What were the most important findings?
Obese animals had higher MT and inflammation biomarkers from the start, and these levels stayed constant throughout the study, whereas lean animals showed significant increases in these same markers that eventually approached the levels seen in obese animals. At baseline, lean and obese animals had similar numbers of observed amplicon sequence variants (ASVs), but obese animals lost ASV diversity during acute SIV infection before rebounding after 39 weeks of ART. Beta diversity differed between the two groups and continued to shift over time in the obese animals, which also showed significant changes in about four times as many bacterial genera as the lean animals. The abstract does not mention Desulfovibrio, sulfate-reducing bacteria, hydrogen sulfide, or sulfur metabolism specifically.
What are the greatest implications of this study?
The findings suggest that obesity establishes a baseline state of elevated gut barrier disruption and inflammation that changes little with SIV infection or ART, while lean animals start healthier but converge toward similarly elevated inflammatory states as infection progresses. This implies that obesity may reshape how the gut microbiome and immune activation respond to HIV infection and treatment, with broader and more sustained microbial community disruption in obese hosts. These results support considering body weight status when evaluating gut health and inflammation in people living with HIV on ART.