Healthy Aging and the Gut Microbiome in People With and Without HIV

Background. Aging-related comorbidities are more common in people with human immunodeficiency virus (HIV) compared to people without HIV. The gut microbiome may play a role in healthy aging; however, this relationship remains unexplored in the context of HIV. Methods. 16S rRNA gene sequencing was conducted on stool from 1409 women (69% with HIV; 2304 samples) and 990 men (54% with HIV; 1008 samples) in the MACS/WIHS Combined Cohort Study. Associations of age with gut microbiome diversity, uniqueness, and genus-level abundance were examined in women and men separately, followed by examining relationships of aging-related genera with frailty (Fried frailty phenotype) and mortality risk (Veterans Aging Cohort Study [VACS] index). Results. Older age was associated with greater microbiome diversity and uniqueness, greater abundance of Akkermansia and Streptococcus, and lower abundance of Prevotella and Faecalibacterium, among others; findings were generally consistent by sex and HIV status. An aging-related microbiome score, generated via combination of 18 age-related genera, significantly increased with age in both women and men independently of demographic, behavioral, and cardiometabolic factors. In general, age was more strongly related to microbiome features (eg, diversity, microbiome score) in men without compared to with HIV, but age-microbiome associations were similar in women with and without HIV. Some age-related genera associated with healthy/unhealthy aging, such as Faecalibacterium (related to reduced frailty) and Streptococcus (related to higher VACS index). Conclusions. Age is associated with consistent changes in the gut microbiome in both women and men with or without HIV. Some aging-related microbiota are associated with aging-related declines in health.