Bulletproof Radio

This episode covers: • Colon Cancer in the Young and Why Risk May Start in Infancy New reporting highlights a troubling rise in early-onset colon cancer, including cases in highly fit endurance athletes. Researchers identified a distinct DNA damage signature linked to colibactin, a toxin produced by certain strains of E. coli, with evidence suggesting the damage may occur in infancy. Dave explains why fitness alone isn’t protective, how early-life microbiome disruption and low-fiber modern diets stack long-term risk, and why earlier screening and gut-supportive habits like fiber, resistant starch, and circadian alignment matter more than ever. Source: https://www.businessinsider.com/why-so-many-young-people-getting-colon-cancer-answer-infancy-2025-12  • Kefir-Derived Bacteria, Immune Aging, and the Thymus A mouse study found that a kefir-derived bacterial strain, even when heat-inactivated, reduced age-related thymus shrinkage and lowered inflam