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.
Section
Science
GLP-1 Drugs and the Gut: What the Trials Reported
These medicines act on the digestive tract by design. Here is what randomized trials and pharmacovigilance data recorded, and what remains uncertain.
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.
Magnesium Forms Compared: What the Absorption Data Show
Oxide, citrate, chloride, amino acid chelate. Absorption has been compared directly across forms. The laxative effect has not, and the difference between those two statements matters.
Low FODMAP, Explained Without the Overreach
The trial evidence is stronger than most diets have. It is also evidence about a short restriction phase, not a permanent way of eating.
What a SIBO Breath Test Can and Cannot Tell You
Nearly 30 percent of control subjects test positive. Here is what the diagnostic accuracy literature says about a result that is often read as definitive.
The American Fiber Gap, in Numbers
Adequate Intake is 25 to 38 grams a day. Measured US intake sits closer to 16. What the surveys and the trials actually show.
Leaky Gut: What Is Measured, and What Is Sold
Intestinal permeability is a real, quantified research variable. 'Leaky gut syndrome' is a marketing category. The distance between the two is the story.
The CFU Number Is the Wrong Thing to Compare
Labels advertise 50 billion, then 100 billion. The published dose-response evidence does not support reading that number as a ranking.