Complaints & connections · borters.ch
A widespread explanatory model: the gut barrier is real and measurable; a distinct diagnosis has not been delineated from it.
Also known as: leaky gut · increased intestinal permeability · leaky gut syndrome
Open in the tool — with search and all the links →This compilation is for information and replaces neither medical diagnosis nor treatment. If you have symptoms, see a doctor.
“Leaky gut” describes the idea that the intestinal wall becomes more permeable, letting substances into the blood that don’t belong there. Altered intestinal permeability does exist — it can be observed in certain diseases (e.g. coeliac disease or inflammatory bowel disease). What is NOT scientifically established, however, is “leaky gut syndrome” as a stand-alone cause of many different complaints such as fatigue, allergies or autoimmune disease. Caution is warranted with expensive tests and “gut-cleanse” programmes marketed around it. The sensible path is to have real underlying conditions assessed and to keep the gut generally healthy — rather than chasing a fashionable diagnosis.
Rather than a fashionable label: have persistent symptoms assessed (e.g. rule out coeliac, irritable bowel).
Varied fibre, little ultra-processed food, activity — this benefits the gut barrier.
Expensive self-tests and aggressive “cleanse” programmes usually add little and can cost money and nerves.
Warning signs like weight loss, blood in the stool or persistent diarrhoea always need assessment.
Zonulin measurements from stool or blood are not methodologically reliable — a high value allows no diagnosis. No reason to build a worry on it.
The organism flattens the small-bowel villi and disturbs uptake measurably — one of the few cases where a permeable lining can be shown. It is treatable, and the lining recovers afterwards.
The permeability of the gut wall can be measured — with sugars such as lactulose and mannitol, or with zonulin in the stool; both methods come from research and are not meant for individual diagnosis. Raised values are found in coeliac disease, chronic inflammatory bowel disease, after infections, on anti-inflammatory painkillers and with alcohol. The cells of the gut wall renew themselves every three to five days — so the wall can change quickly, in both directions.
There is no treatment that “seals” the gut wall. Glutamine, zinc and collagen have been studied as building blocks of the lining; the data come mostly from cell experiments and from special situations such as severe illness. What changes the wall measurably is food: fibre from which the gut bacteria make butyrate, which feeds the lining cells directly. Anti-inflammatory painkillers and alcohol raise permeability measurably.
Zonulin is a body protein that controls the tight junctions between gut cells. When it rises, those junctions briefly open and the wall becomes a little more permeable — a normal regulating mechanism, not damage in itself.
A gluten component (gliadin) can stimulate zonulin release and briefly raise permeability. In a healthy gut the junctions then reseal, and the lining renews constantly anyway — normal grain intake does not make a “sick” gut.
The zonulin response to gluten is markedly stronger in celiac disease and partly in gluten sensitivity. Without that predisposition, there is no need to avoid grains for the gut’s sake.
Non-specific complaints are often broadly blamed on “leaky gut” — usually without evidence.
In coeliac disease or IBD the barrier is measurably altered — as part of the disease, not as a diagnosis of its own.
The “leaky gut tests” offered online are not meaningful.
The most useful value in bowel complaints of all: it separates a sensitive bowel from a true inflammation — and that distinction changes everything else.
The most important treatable illness that can lie behind these complaints. The value only holds while gluten is still being eaten.
An iron shortage without loss of blood points to disturbed uptake and is a graspable finding rather than an assumption.
Taken up right at the end of the small bowel and needing a helper from the stomach. If either place is affected a deficiency arises — often only after years, because the liver holds a store.
Taken up in the upper small bowel and needing stomach acid. Acid blockers, an inflamed lining and silent blood losses often come together here.
One of the fat-soluble vitamins, lost with the fat when fat digestion is disturbed. Fatty, floating stools over months are the pointer to it.
Needs vitamin D for uptake, and with disturbed fat digestion it additionally binds to fatty acids in the bowel. So bone density and bowel disease hang together more closely than assumed.
Lost in considerable amounts with lasting diarrhoea. Signs are cracked corners of the mouth, loss of taste, poor wound healing and thinning hair.
The cells of the gut lining use glutamine as their preferred energy source. Studied at 5–30 g a day; the human studies are small and mostly concern seriously ill patients, not everyday life.
Zinc carnosine is best studied for the stomach and gut lining — 75 mg a day over 8 weeks. Zinc in general works only with a proven deficiency; above 40 mg a day over months it disturbs copper uptake.
Clearly worthwhile and well supported when deficient — vegan, older adults, certain drugs. No energy boost without a deficiency.
Clearly effective with proven deficiency, useless without. Take only with a documented deficiency — excess is harmful.
Clearly worthwhile and well studied when deficient; fewer data for the wider uses. Fat-soluble — check blood levels at high doses.
That sustained stress makes the gut barrier more permeable is shown in the laboratory and in small human studies. What follows from it is distinctly less clear — permeability is a measurable phenomenon, but not a disease.
Short-chain fatty acids from the fermentation of fibre feed the gut wall and release GLP-1. That is the best-supported way to strengthen the barrier — through food, not through a supplement.
Short-chain fatty acids from fibre are the main food of the gut lining cells. Studied at 25–30 g fibre a day; the cell layer renews in about 3–5 days, measurable change takes weeks.
Both raise permeability in trials — depending on the amount. Not fruit is meant, but 50 g of fructose and more a day, as sweetened drinks add up to.
What really feeds the lining is fibre and the butyric acid that comes from it.
Among the most named approaches; the studies mostly concern single strains, not the concept.