Senescence-associated loss of intestinal α1,2-fucose disrupts a modifiable host-microbiome homeostasis axis in people with HIV

BackgroundPeople with HIV (PWH), despite effective antiretroviral therapy (ART), experience disrupted intestinal homeostasis characterized by microbial dysbiosis and impaired intestinal barrier integrity, which contribute to chronic inflammation and aging-associated comorbidities. However, tractable mechanisms contributing to this dysfunction remain poorly defined. ObjectiveTo determine whether acquired loss of intestinal 1,2-fucose, a host-derived intrinsic prebiotic glycan that supports colonization by short-chain fatty acid (SCFA)-producing bacteria essential for intestinal barrier integrity, contributes to microbiome disruption, impaired epithelial resilience, inflammation, and biological aging in PWH. DesignIleal and colonic biopsies, isolated crypts, stool, and blood from PWH on ART and controls underwent multi-omic analyses. Findings were mechanistically interrogated using stool anaerobic fermentation assays and 3D intestinal organoid models of stress-mediated epithelial disruption. ResultsIn intestinal tissues, PWH exhibited reduced 1,2-fucosylation and increased senescence-associated expression of the fucose-degrading enzyme -L-fucosidase. Lower 1,2-fucose tracked with depletion of SCFA-producing bacteria, increased inflammation, and premature biological aging. In anaerobic fermentations, stool from PWH produced fewer SCFAs than controls, whereas supplementation with the human-milk-oligosaccharide-derived 1,2-fucose donor 2'-fucosyllactose restored SCFA production and improved intestinal organoid resilience to stress-mediated disruption. ConclusionThese findings identify acquired loss of intestinal 1,2-fucose as a modifiable host-microbiome mechanism linking epithelial senescence, microbial metabolic dysfunction, impaired barrier resilience, inflammation, and biological aging in treated HIV infection. SUMMARY BOXO_ST_ABSWhat is already known on this topicC_ST_ABSPeople with HIV on suppressive antiretroviral therapy frequently have persistent intestinal barrier dysfunction, microbial dysbiosis, chronic inflammation, and accelerated biological aging, but the host mechanisms that maintain this disrupted mucosal state remain incompletely defined. What this study addsThis study identifies acquired loss of intestinal 1,2-fucosylation as a feature of treated HIV infection and links this defect to a host fucosidase-high, senescence-enriched mucosal niche, depletion of SCFA-producing bacteria, impaired tight junction-associated barrier signatures, inflammation, and biological aging phenotypes. How this study might affect research, practice or policyThese findings support intestinal glycan ecology as a modifiable host-microbiome axis and provide a rationale for testing 1,2-fucose-replenishing strategies, such as 2'-fucosyllactose, to restore microbial metabolic output and improve epithelial resilience in people with HIV.