Alcohol, aging, and the gut microbiome: Intersections of immunity, barrier dysfunction, and disease

Alcohol consumption exerts complex, dose- and context-dependent effects on human health, particularly by influencing the gut microbiome, intestinal barrier integrity, immune regulation, and aging processes. Genetic variation and advancing age are two major, and often interacting, factors that modify the risk of alcohol-related diseases.
Among genetic factors, the prevalent aldehyde dehydrogenase 2 polymorphism (ALDH2∗2) compromises acetaldehyde clearance, driving toxic metabolite accumulation, oxidative stress, and increased intestinal permeability that disrupts gut microbial communities, even at low levels of alcohol consumption. Heavy and chronic alcohol use further disrupts gut microbial communities, erodes mucosal integrity, and drives systemic inflammation, contributing to alcohol-associated liver disease (ALD), neuroinflammation, and multi-organ injury. Aging independently worsens these effects by promoting chronic low-grade inflammation and impaired immune responses, heightening susceptibility to alcohol-induced patholog
In specific contexts, such as certain autoimmune diseases, low to moderate alcohol intake may exert immunomodulatory effects and influence the gut microbiome, potentially contributing to reduced inflammation and alterations in microbial composition.
A review synthesises current mechanistic insights into how alcohol, host genetics, the gut microbiome, immune regulatory pathways, and aging intersect to influence disease risk. The authors state that as global populations age and the burden of alcohol-related health issues rises, there is an urgent need for integrated, systems-level approaches. Future research should prioritise precision-based, gut-targeted strategies aimed at restoring microbial balance, maintaining intestinal barrier integrity, and mitigating alcohol-related harm across the lifespan.
Source: Esther Melamed, Wiramon Rungratanawanich, Suthat Liangpunsakul, Katherine A. Maki, Rebecca L. McCullough, Cristina Llorente, Alcohol, aging, and the gut microbiome: Intersections of immunity, barrier dysfunction, and disease, Alcohol, Volume 128, 2025, Pages 1-12, ISSN 0741-8329,