100 years ago, the average child would ingest nearly a pound of dirt by the time they turned ten
18 Dec 2025 · 1 min

0:44
Aaron Hartman, MD explains how dirt exposure builds a healthy gut microbiome. A century ago, kids ingested nearly a pound of soil by age ten, seeding their guts with bacteria similar to those in fermented foods. Your microbiome produces 75% of your neurotransmitters and detoxifies a third of all drugs.
Questions this video answers
About one pound.
75%.
One third.
December 18, 2025.










