Distinct intestinal microbial signatures linked to accelerated systemic and intestinal biological agingOriginal 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 asked whether living with HIV accelerates biological aging in the intestines, and whether gut microbes drive it. It combined epigenetic aging clocks, tight junction imaging, 16S rRNA sequencing of the V1-V2 region, and metabolomics. Samples spanned colon and ileum biopsies, blood, and stool. Correlation networks linked microbes, metabolites, and aging. The design was a systems biology comparison of tissue and blood.
Who was studied?
The cohort was 25 people with HIV on suppressive antiretroviral therapy and 23 people without HIV, at Rush University in the United States. Groups were matched for age, sex, BMI, and ethnicity. All HIV-positive participants had viral loads below 50 copies per milliliter. People on special diets or with celiac disease were excluded. Colon, ileum, blood, and stool were sampled from each participant.
What were the most important findings?
Blood biological age was accelerated by 2.59 to 7.05 years in people with HIV on therapy. Aging also accelerated in the ileum (four clocks) and colon (two clocks). Tight junction proteins fell and microbial translocation markers rose, both tied to faster aging. Pro-inflammatory bacteria that catabolize tryptophan, enriched in the gut, correlated with accelerated aging. Depleted butyrate producers tracked with slower aging, alongside higher tryptophan catabolites and lower hippuric acid.
What are the greatest implications of this study?
The work links intestinal microbial dysbiosis, a leaky gut, and specific metabolites to accelerated aging in people with HIV on therapy. Mucosal tissue signatures, not fecal ones, tracked most closely with aging. This reflects HIV, antiretroviral therapy, sexual practices, and other factors combined. It is a human association study, so mechanisms and causation remain unproven.