The Gut-Brain Axis: Signal, Hype, and the Gap Between
The anatomy is uncontested and the human trial evidence is thinner than the headlines. Here is where each part of the claim actually stands.
microbiome
At-Home Stool Tests: Which Ones Have Been Validated
Some mail-in stool tests carry national screening recommendations and published accuracy data. Others were measured against a reference material and disagreed with each other.