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Glossary

Leaky gut

Defined in topic 12

Raised permeability of the gut lining, real and measurable in celiac and inflammatory bowel disease. That restoring the barrier improves any illness is unproven, and the commercial version is weaker still.

Published Updated

Graded claims that mention Leaky gut

  • Is leaky gut real?Real in specific diseases, unproven as an everyday diagnosis.Evidence grade: Emerging. Early, small, animal-only, or actively contested.

Where this comes from

In the reference topic that owns this term

Reference topic 12, The Gut That Expects Dirt, states the mismatch as a card: what the system evolved to expect, what it gets instead, and what happens in the gap.

Mismatch card

What it expects

Tens of grams of fiber a day from many plants, a seasonal menu, and microbes from soil and food.

What it gets

About 17 g of fiber a day (the US adult average), a narrow and refined diet, courses of antibiotics, and sanitized surroundings.

What happens in the gap

Fewer species and less fermentation, with links to disease still being untangled.

The full card, and the topic behind it

What that chapter recommends

3 of the 7 graded recommendations in Reference topic 12, strongest evidence first. How the grades work.

  1. Eat more fiber, from more kinds of plant

    StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.

    Aim for at least 25 g a day. In meta-analyses the benefit was greatest at 25-29 g, and more may help. The US adult average is about 17 g.

    Read it in full

  2. Add fermented foods with live cultures

    ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.

    Trial participants worked up over four weeks to about six servings a day; start with one. Yogurt, kefir, most cheeses, miso and unheated fermented vegetables can carry live microbes; bread, vinegar pickles and...

    Read it in full

  3. Skip the probiotic aisle

    ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.

    unless a clinician recommends one for a specific reason.

    Read it in full

Related terms

The argument behind this term, its studies and its notes are in Reference topic 12 of the reference library. The book gives the practical version. Get the book.