Bulletproof Radio

This week's stories: *Mud Playgrounds Double Kids' Bacterial Diversity and Spike Immune Genes 30% Finland swapped rubber playground surfaces for natural soil and mud across eight kindergartens — and after just one month, kids in dirt had twice the bacterial species diversity on their skin and a 30% increase in expression of ten immune-related genes. Dave breaks down why your immune system requires microbial exposure to calibrate properly, what the hygiene hypothesis actually means for adults, and the dead-simple weekly habit that primes your innate immunity the same way. Sources: https://creators.yahoo.com/lifestyle/story/finland-replaced-artificial-playground-surfaces-with-natural-elements-like-mud-and-soil--and-the-results-surprised-even-researchers-184318556.html https://www.sciencedaily.com/releases/2026/04/mud-playground-immunity.htm *Mixing Exercise Types Cuts All-Cause Mortality Up to 40% in 170,000-Person Study A 30-year BMJ Medicine cohort study found that peop