Environ Health Perspect. 2026 Apr 17;134(1):75-90. doi: 10.1021/EHP.6c00064. eCollection 2026 May 5.
ABSTRACT
BACKGROUND: Emerging observational studies suggest that air pollution can influence the gut microbiome. However, this association is often highly confounded by factors, such as diet and poverty. The gut virome may influence respiratory health independent of the gut microbiome. We recently demonstrated in a randomized waitlist-controlled trial (ClinicalTrials.gov NCT03351504) that a clean lighting intervention reduced the level of personal exposure to air pollution among adult women in rural Uganda. OBJECTIVES: To determine the effect of a solar lighting intervention on changes to the gut microbiome and virome and secondarily to determine the association between these changes on lung health. METHODS: Between 2018 and 2019, we collected stool samples and assessed respiratory symptoms and spirometry from 80 adult women living in rural Uganda at baseline and 12 and 18 months postrandomization. The intervention group received a solar lighting system after randomization, while the waitlist-controlled group received one at 12 months. Deep metagenomics sequencing of stool was performed and profiled for nonviral and viral taxonomic composition. The primary analysis focused on pre- vs postintervention changes due to power considerations, adjusting for potential confounding by age, diet, antibiotic use, and season. A sensitivity analysis was conducted using intention-to-treat principles. When comparing pre- vs postintervention periods, we used sparse partial least-squares models to identify nonviral and viral signatures of reduced air pollution exposure. Mixed effects models were used to evaluate changes in health outcomes as well as associations between microbial signatures of reduced air pollution exposure and health. RESULTS: The average age was 39.2 years. The solar lighting intervention led to larger changes in viral compared to nonviral microbial community structure and differential abundance of bacteria, eukaryotes, and viruses. Provision of solar lighting systems was associated with a reduction in the presence of respiratory symptoms from 57.1% to 36.1% (p = 0.002), while there was no impact on lung function. Microbiome and virome signatures had AUCs of 0.74 and 0.76, respectively, in predicting pre- vs postintervention stool samples. Microbiome signatures were associated with a lower risk of respiratory symptoms (OR = 0.68 (0.49 — 0.94), p = 0.020). CONCLUSION: Among adult women living in rural Uganda, both nonviral and viral components of the gut microbial community changed after a clean lighting intervention. Microbiome signatures reflective of lower air pollution exposures were associated with improved respiratory symptoms. These observations suggest that air pollution may influence lung health through the gut-lung axis, warranting further exploration in future intervention studies.
PMID:42148043 | PMC:PMC13151042 | DOI:10.1021/EHP.6c00064
