Vitamin D and Gut Microbiota and Dementia Risk in Older Adults with Chronic HIV infection and Demographically Matched Community Controls

This project explores the intersection of nutritional status, microbial ecology, and cognitive health among older adults living with chronic HIV and comparable community peers. Supported by the National Institute on Aging, this multi-year study is positioned to examine associations among vitamin D levels, gut microbiota composition and function, and markers or risk of dementia in a population facing elevated aging-related health challenges. The project’s focus reflects growing scientific interest in how systemic factors such as micronutrient status and the gut microbiome may modulate neurocognitive trajectories, particularly in populations with chronic viral infection and complex comorbidities.

The study’s target population—older adults with chronic HIV infection alongside demographically matched community controls—allows for direct comparison between groups who share age, sex, race/ethnicity and other sociodemographic characteristics but differ by HIV status. This design supports investigation into whether relationships between vitamin D, gut microbial profiles, and cognitive outcomes are specific to chronic HIV infection, amplified by it, or shared across older adult populations. By integrating measures of vitamin D status with assessments of gut microbiota, the project aims to clarify whether vitamin D correlates with particular microbial signatures that have been linked to inflammation, metabolic health, or neural function, and whether these patterns correspond to cognitive impairment or increased dementia risk.

Beyond identifying associations, the study is poised to inform mechanistic hypotheses about pathways connecting vitamin D, the gut microbiome, and brain health. For older adults living with HIV, who may experience accelerated or accentuated aging-related changes and higher burdens of cognitive impairment, clarifying modifiable factors is especially important. Findings could point toward prevention strategies, including nutritional or microbiome-directed approaches, that may be applicable to both people with chronic HIV and the broader aging population. The inclusion of demographically matched community controls enhances the potential translational relevance of results by situating any HIV-specific findings within a broader population context.

Over its funded period, the project will generate data that contribute to understanding how micronutrient status and gut microbial ecology relate to dementia risk indicators among older adults. The work aligns with priorities in aging research to identify modifiable risk factors and biological pathways that underlie cognitive decline. By centering older adults with chronic HIV infection and carefully matched peers, this study provides an opportunity to address gaps in knowledge at the intersection of infectious disease, gerontology, nutrition, microbiome science, and neurodegeneration research. Ultimately, the project’s outcomes may guide future interventions and larger-scale studies aimed at reducing dementia risk in diverse aging populations.