Chapter 7: The Gut That Expects Dirt
By cell count, you are more microbe than human. Your gut contains 38 trillion organisms forged by 90 million years of coevolution -- and modern life is wiping them out.
◆ Key Insights
Western guts have lost 40% of their microbial diversity compared to hunter-gatherer populations
Your gut bacteria produce neurotransmitters, train your immune system, and control inflammation -- they're not passengers, they're partners
Autoimmune diseases have increased 300-900% in industrialized nations in the past 50 years as microbial exposure has collapsed
Cesarean-born infants miss the microbial baptism of the birth canal -- and carry measurably different immune signatures for years
The gut-brain axis means your mood, cognition, and mental health are directly influenced by organisms most people try to kill with sanitizer
Read the full chapter to discover why the war on germs may be the most consequential mistake of modern medicine.
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