Precision Microbiota Interventions for Senoreduction Trial

This is a randomized, double-blind, controlled, crossover mechanistic clinical trial in people with HIV who have recent alcohol use. Participants are randomized to receive either Limosilactobacillus reuteri probiotic or blueberry extract first for 4 weeks, followed by a 6-week washout period, then crossover to the alternate intervention for 4 weeks. Each participant receives both interventions.

Both interventions are generally recognized as safe (GRAS) dietary supplements and are not intended to diagnose, treat, cure, or prevent disease. This study is not conducted under an Investigational New Drug (IND) application and does not involve FDA-regulated investigational products.

Biospecimen collection and clinical assessments are performed at baseline and Week 4 of each intervention period. The primary analysis compares within-participant changes in immune senescence markers between interventions using a crossover design framework and accounts for period and sequence effects.

Participants will be recruited from HIV clinical care programs, affiliated clinics, and community outreach efforts in the New Orleans area.

A 6-week washout period is included to minimize potential carryover effects.

• Limosilactobacillus reuteri (Dietary supplement): Administered as 8 capsules daily (4 twice daily) for 4 weeks. Each daily dose contains 1×10\^10 CFU total in a 1:1 ratio of two strains. This is a GRAS dietary supplement and not an FDA-regulated investigational product.
• Blueberry extract (Dietary supplement): Administered as 8 capsules daily (4 twice daily) for 4 weeks, providing 500 mg anthocyanins per day. This is a GRAS dietary supplement and not an FDA-regulated investigational product.

Primary outcomes

• Change in circulating senescent T cell numbers [Time 0 to Week 4 of treatment period]: Change in circulating CD3+CD8+CD28-CD38+ T cell count (cells/µL) during treatment period. Measured by multiparameter flow cytometry. The primary endpoint is the within-participant difference in change from baseline.

Secondary outcomes

• Change in additional senescent T cell phenotypes [Baseline and Week 4]: Flow cytometry-defined subsets
• Change in epigenetic age estimation [Baseline and Week 4]: Change in DNA methylation-based age estimates using epigenetic clock analyses.

Other outcomes

• Change in additional senescent T cell phenotypes [time 0 to 4 weeks]: Exploratory analyses of additional T cell phenotypes including assess additional senescence markers including lysosomal-β-galactosidase (GLB1), proinflammatory SASP (IL-1β, IL-2, IL17A, IL-18, TNFa, IFNg, HMBG1), proliferation (Ki67), CD27, CD57, and DNA damage (p-H2A.X) in T cells at multiple stages of maturation including naïve, effector, memory, and TEMRA.
• Microbiome and metabolite profiles [Baseline and Week 4]: Stool microbiome (phylogenetic analysis and bacterial genes quantification) and metabolite analyses.

Sex: All, ages: 40 Years to any

Inclusion Criteria:

* Age ≥40 years
* People with HIV
* Recent alcohol use defined as ≥42 grams in the prior week and positive urine ethyl glucuronide (EtG)

Exclusion Criteria:

* Probiotic use in past 3 months
* Recent antibiotics or immunosuppressives
* Allergy to study products
* Pregnancy or breastfeeding
* Inability to comply

• David A Welsh, MD, Principal investigator, LSU Health New Orleans