Sustained gut dysbiosis and intestinal inflammation show correlation with weight gain in person with chronic HIV infection on 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 longitudinal study asked how the gut microbiota of people with chronic HIV changes during long-term antiretroviral therapy, and whether those shifts track with inflammation and weight. Researchers compared stool and blood collected at baseline (2017-2018) and at a follow-up about four years later. They sequenced the 16S rRNA gene V3-V4 region, predicted bacterial functions with PICRUSt2, and measured plasma cytokines. Correlations linked microbiota change to body mass index and inflammatory markers.
Who was studied?
The cohort was 46 people with HIV attending a Tokyo hospital, all on antiretroviral therapy for at least 10 years. Median age was 51 years and 91.3 percent were male. Most reported male-to-male sexual transmission. Nearly all had suppressed virus (45 of 46 below 50 copies/mL) and stable CD4 counts. At baseline, 16 were overweight (body mass index at or above 25) and 30 were normal weight. No healthy control arm was followed at follow-up.
What were the most important findings?
Despite effective therapy, bacteria in the Clostridia class that produce short-chain fatty acids declined, while opportunistic Gammaproteobacteria increased. Alpha diversity did not change overall. Body mass index rose modestly (mean increase 0.47 kg/m2). The rate of weight gain correlated with faster loss of Anaerostipes and Coprococcus 3. People with low Parabacteroides had lower diversity and greater weight gain. Rising body mass index also correlated with higher plasma IL-16 and CXCL13, markers tied to gut inflammation and bacterial translocation.
What are the greatest implications of this study?
The findings suggest that even well-controlled HIV leaves a persistently disturbed gut, drifting toward an environment with metabolic consequences. Loss of Parabacteroides and certain Clostridia may help explain age-related weight gain and inflammation in treated HIV. These are correlations in a small single-center cohort with no healthy comparison group, so causation is not established. Age-related weight gain also occurs without HIV. The authors call for larger studies and mechanistic work on bacterial bile-acid metabolism.