How alcohol drives gut-derived, low-grade systemic inflammation.
What the evidence says
- Alcohol compromises the intestinal barrier through direct epithelial injury (cell death, erosions; acetaldehyde-driven DNA damage and oxidative stress) and through disruption of the tight junctions between gut cells[1]
- A leakier gut lets bacterial lipopolysaccharide (LPS/endotoxin) translocate into the bloodstream — plasma endotoxin rises in step with intestinal permeability (endotoxemia)[1]
- Circulating LPS activates the innate immune system via Toll-like receptor 4 (TLR4), raising pro-inflammatory cytokines and driving low-grade systemic and hepatic inflammation[1]
- Alcohol also shifts the gut microbiome toward more gram-negative, LPS-bearing bacteria and fewer short-chain-fatty-acid producers, further weakening the barrier[1]
- The effect is dose-related and most established for excessive/chronic intake; this is a mechanism, not a claim that any amount of alcohol is meaningfully inflammatory[1]