All 885 tips from all chapters, sorted by topic and confidence score. See what is well supported and what is still experimental.
| Topic | Established | Well supported | Promising | Plausible | Experimental |
|---|---|---|---|---|---|
| Gut barrier | 3 | 7 | 30 | 29 | 7 |
| Opportunistic pathogens | 8 | 42 | 31 | 26 | 12 |
| Bacteriophages | 1 | 2 | 5 | 7 | |
| Microbial diversity | 9 | 22 | 62 | 65 | 9 |
| Gut-brain axis | 4 | 18 | 36 | 38 | 3 |
| Digestive function | 22 | 51 | 71 | 64 | 9 |
| Small intestine colonisation | 1 | 12 | 21 | 27 | 4 |
| Immune system and inflammation | 10 | 21 | 42 | 45 | 9 |
| Total | 57 | 174 | 295 | 299 | 60 |
Tap a number to see the tips below. Darker cells contain more tips.
Gut barrier · Clear selection
Trust score 5 of 5:Established Medical treatments
Useful steps are a blood test for coeliac disease, faecal calprotectin for diarrhoea and, depending on age and findings, a colonoscopy. Warning signs such as weight loss, blood in the stool, symptoms at night, fever or anaemia always need medical assessment.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 1 sources
Trust score 5 of 5:Established Medical treatments
Get a blood test for tissue transglutaminase antibodies while you are still eating gluten. Coeliac disease is the most common well-documented cause of a disturbed barrier.
The gut barrier 1 sources
Trust score 5 of 5:Established Medical treatments
Mucus and blood in the stool, diarrhoea at night or weight loss should be checked by a doctor, for example with faecal calprotectin or a colonoscopy. A little mucus in the stool can be normal; what stands out is when it is new, persistent or comes with blood and pain.
The mucus layer and additives 1 sources
Trust score 4 of 5:Well supported Lifestyle
For sessions over two to three hours, a mix of glucose and fructose delivers more energy than one type alone, and less stays in the gut. Pure fructose or sugar alcohols like sorbitol, on the other hand, are poorly tolerated by many. Newer products such as hydrogels have so far shown no advantage over regular gels.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 4 of 5:Well supported Lifestyle
Find the cause (leak, cold wall, too little airing), dry out and remove affected material. Air regularly with short bursts of open windows and dry water damage promptly. For larger areas, call in professionals. According to the evidence this reduces respiratory symptoms, even without measuring spores.
Trust score 4 of 5:Well supported Lifestyle
Throw away discoloured, shrivelled or mouldy nuts, figs and grains. Store dry, not too warm and not for too long, and buy fresh. Eating a varied diet spreads the risk.
Trust score 4 of 5:Well supported Medical treatments
Cough, wheezing, asthma or a constant runny nose in a damp home should be checked by a doctor, often with an allergy test and lung function test. Children in particular should be examined early.
Trust score 4 of 5:Well supported Medical treatments
These tests are not approved or validated for diagnosis. A "positive" result usually only shows what you have eaten.
Trust score 4 of 5:Well supported Medical treatments
If you regularly take NSAIDs such as ibuprofen or diclofenac, talk to your doctor about alternatives. Iron deficiency or unexplained anaemia while taking NSAIDs can also point to small-bowel damage.
The gut barrier 1 sources
Trust score 4 of 5:Well supported Medical treatments
With diarrhoea, mucus or blood in the stool, weight loss or night-time symptoms, faecal calprotectin helps distinguish inflammatory bowel disease from IBS.
The gut barrier 1 sources
Trust score 3 of 5:Promising Lifestyle
Legumes, whole grains, vegetables, nuts and seeds. Different fibres feed different bacteria and together produce more short-chain fatty acids.
Trust score 3 of 5:Promising Lifestyle
It forms when cooked potatoes, rice or pasta cool down, and is found in green bananas, oats and legumes. Potato starch raised butyrate the most in one study.
Trust score 3 of 5:Promising Lifestyle
Raise the amount over several weeks and drink enough. This gives the microbiota time to adapt, and bloating usually stays bearable. With a sensitive gut, well-cooked foods and small portions suit a start.
Trust score 3 of 5:Promising Natural supplements
A mild, well-tolerated soluble fibre that improved symptoms in IBS in a randomised, placebo-controlled trial. It suits a gentle start when other fibres cause a lot of bloating.
Trust score 3 of 5:Promising Medical treatments
For inflammation in the rectum, butyrate enemas added to standard treatment improved the outcome in a randomised trial. This is a medical treatment, not a self-experiment.
Trust score 3 of 5:Promising Medical treatments
If even small amounts of fibre trigger severe bloating or pain, small intestinal bacterial overgrowth or another digestive disorder may be behind it. A breath test and a talk with your doctor can clarify this before you give up fibre altogether.
Trust score 3 of 5:Promising Lifestyle
The gut gets used to absorbing sugar during exercise. In one study, runners took 90 grams of carbohydrate per hour during daily sessions for two weeks. Afterwards they had clearly fewer symptoms during exercise, less undigested sugar in the gut, and ran further. So don’t try gels for the first time in a race; build up slowly in long training sessions.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 3 of 5:Promising Lifestyle
Eating less fibre, fat and fermentable sugars (FODMAPs) in the one to three days before a long race reduced symptoms in two small studies. Ideally have the last larger meal two to four hours before. This is not meant for everyday life, because in the long run the gut microbiota needs fibre. Gluten-free did not help in studies when there was no coeliac disease.
Gut and endurance sport: runner’s gut, cramps and what helps 3 sources
Trust score 3 of 5:Promising Lifestyle
The hotter the body gets, the more the gut suffers. In the heat, lower the pace, start well hydrated and drink regularly along the way. If you regularly get cramps or diarrhoea on hot days, move your hard sessions to the cool morning hours.
Gut and endurance sport: runner’s gut, cramps and what helps 3 sources
Trust score 3 of 5:Promising Medical treatments
Painkillers like ibuprofen, diclofenac or naproxen increase the gut damage from exercise and make the gut wall leakier. You should not take them preventively before a run. For pain after exercise, talk to a doctor or pharmacist about alternatives.
Gut and endurance sport: runner’s gut, cramps and what helps 1 sources
Trust score 3 of 5:Promising Medical treatments
Visible blood after a hard run can come from a brief circulation problem in the large intestine, which usually heals on its own. But it can also have other causes, such as inflammatory bowel disease or a polyp. That is why it always belongs in medical hands, especially if it comes back or if pain, fever or dizziness are added.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 3 of 5:Promising Medical treatments
If you run a lot and feel tired, are getting slower or look pale, have your iron stores (ferritin) and a blood count checked. Iron deficiency is common in endurance athletes, but not always harmless: with unexplained iron deficiency, coeliac disease or bleeding in the gut should also be considered.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 3 of 5:Promising Lifestyle
The benefit for blood pressure appeared with a healthy diet afterwards. Use fasting as a starting point for more plants and less ultra-processed food, not as compensation for the rest of the year.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking 1 sources
Trust score 3 of 5:Promising Lifestyle
Going without water has no proven benefit but real risks for the kidneys and circulation.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking no source of its own, score based on judgement
Trust score 3 of 5:Promising Medical treatments
Longer fasting is best done in a fasting clinic or with medical supervision. Do not fast with underweight, an eating disorder, during pregnancy or breastfeeding, with type 1 diabetes, kidney or liver disease, or during a flare of inflammatory bowel disease. Discuss medication beforehand.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking 1 sources
Trust score 3 of 5:Promising Medical treatments
Anyone losing weight very quickly over weeks or who has had gallstones before should discuss this with their doctor. On very-low-calorie diets, ursodeoxycholic acid is sometimes given as prevention.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking 1 sources
Trust score 3 of 5:Promising Medical treatments
Blood pressure medicines, water tablets, insulin and other diabetes drugs (especially SGLT2 inhibitors), blood thinners and drugs with a narrow therapeutic range must be adjusted or paused before fasting. Your doctor decides this, not you alone.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking no source of its own, score based on judgement
Trust score 3 of 5:Promising Medical treatments
If you have fasted more than about five days, are underweight or have eaten little for a long time, have the refeeding supervised medically, with checks of phosphate, potassium and magnesium, to recognise a refeeding syndrome.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking no source of its own, score based on judgement
Trust score 3 of 5:Promising Lifestyle
Throw away soft and moist foods entirely: bread, yoghurt, jam, cooked dishes, soft fruit, nuts. For hard cheese and firm vegetables, cut off generously, about 2.5 cm around the spot.
Trust score 3 of 5:Promising Lifestyle
Patulin forms mainly in apples with rotten spots. For juice, purée or compote take only sound fruit and cut rotten spots away generously. That keeps exposure low.
Trust score 3 of 5:Promising Lifestyle
Visible mould, damp damage and a musty smell are enough to act. Measured spore counts or toxins in the air have proved to say little. The money is better spent on remediation.
Trust score 3 of 5:Promising Medical treatments
Anyone with chronic hepatitis B or C, or who often eats heavily contaminated foods (for example in regions with damp-stored maize and peanuts), should have liver values checked regularly. The role of aflatoxins in liver cancer risk is well established.
Trust score 3 of 5:Promising Medical treatments
Fatigue, concentration problems and digestive symptoms in a damp home can also have other, treatable causes. A basic medical work-up (blood count, iron, thyroid, coeliac test, sleep, mood) helps more than a special test.
Trust score 3 of 5:Promising Lifestyle
Fewer NSAID painkillers and less alcohol, more fibre from whole foods, enough sleep. The colostrum and zinc carnosine studies mainly show how hard painkillers and overheating hit the gut wall. Avoiding these triggers works without a capsule.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 2 sources
Trust score 3 of 5:Promising Natural supplements
Zinc is useful for a proven deficiency, which can occur with chronic diarrhoea or Crohn's disease. Do not stay above the upper limit of 25 mg a day for long without medical monitoring, or you risk copper deficiency. It can also weaken some antibiotics if both are taken at the same time.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 2 sources
Trust score 3 of 5:Promising Medical treatments
This matters especially if you take anticoagulants or antibiotics, have liver disease or are pregnant. Anyone taking zinc for months should have copper and a blood count checked.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 2 sources
Trust score 3 of 5:Promising Medical treatments
The positive trial tested curcumin in addition to standard therapy, never instead of it. Agree on it with your care team.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 1 sources
Trust score 3 of 5:Promising Lifestyle
Alcohol increases the permeability of the gut lining, especially in larger amounts. A few days without alcohol are often enough for the lining to recover.
The gut barrier no source of its own, score based on judgement
Trust score 3 of 5:Promising Lifestyle
For long endurance sessions in the heat: drink enough, adapt your pace, do not push to the limit on an empty stomach. If you regularly get diarrhoea or cramps after runs, breaks and a slower build-up do your gut good.
The gut barrier no source of its own, score based on judgement
Trust score 3 of 5:Promising Natural supplements
In a randomised trial, glutamine (3 × 5 g daily) clearly improved symptoms and permeability in IBS after a gut infection. The trial was criticised for its methods and has not yet been independently confirmed.
The gut barrier 2 sources
Trust score 2 of 5:Plausible Lifestyle
A lot of meat or protein powder with little fibre shifts fermentation in the large intestine towards unfavourable breakdown products.
Butyrate and other short-chain fatty acids no source of its own, score based on judgement
Trust score 2 of 5:Plausible Lifestyle
Watch your Bristol stool form: types 3 and 4 count as ideal. Very hard, infrequent stool points to long transit with more protein fermentation. Enough fluid, exercise and fibre often help.
Trust score 2 of 5:Plausible Natural supplements
Sodium or calcium butyrate has been studied in small trials in ulcerative colitis and IBS, with mixed results. A large part is already absorbed in the small intestine; encapsulated forms are meant to prevent this. Fibre is the better-supported route.
Trust score 2 of 5:Plausible Lifestyle
If you get heartburn when running, it often helps not to eat anything substantial two to three hours before training. Cycling or swimming shake the belly less. If you still have regular symptoms, have them checked by a doctor.
Gut and endurance sport: runner’s gut, cramps and what helps 1 sources
Trust score 2 of 5:Plausible Natural supplements
Two reviews of around 10 to 26 studies came to different conclusions. Overall, supplements brought no clear advantage; for probiotics there was a moderate but uncertain effect. Which strain helps at what dose is unclear. A trial over a few weeks in training usually does no harm, but it is not a proven approach.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 2 of 5:Plausible Natural supplements
In many small studies, glutamine and colostrum (first milk from cows) lowered the damage markers in the blood after exercise. A meta-analysis did not show that athletes also feel better or are faster with them. More on this in the chapter on leaky gut supplements.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 2 of 5:Plausible Natural supplements
If iron deficiency has been found: after hard exercise the hormone hepcidin slows iron absorption for a few hours. In a study with runners, iron was absorbed best when taken in the morning shortly after training, and less well in the afternoon. Only take iron after a blood test, because too much is harmful.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 2 of 5:Plausible Medical treatments
With irritable bowel syndrome or inflammatory bowel disease you don’t have to give up sport; moderate exercise often helps. If you are planning a marathon or longer races, discuss it with your care team, because how safe very hard efforts are in that case has barely been studied.
Gut and endurance sport: runner’s gut, cramps and what helps 2 sources
Trust score 2 of 5:Plausible Lifestyle
Only if you are healthy, so not with underweight, an eating disorder, pregnancy, breastfeeding or type 1 diabetes: one to three days with vegetable broth and diluted juice are a cautious start. Drink plenty, get salt from the broth, stay physically calm, and stop if you feel dizzy or have palpitations. With illnesses or medication, check with a doctor first, because blood pressure medicines and some diabetes medicines can become dangerous during fasting.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking 1 sources
Trust score 2 of 5:Plausible Lifestyle
Plan about half a day to a day of refeeding for each day of fasting: first steamed vegetables, soup, porridge, then gradually more fibre and legumes, so the gut microbiota gets food again.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking 1 sources
Trust score 2 of 5:Plausible Natural supplements
Five days with few calories, little sugar and protein, but enough fat and vegetables. Well tolerated in a study of 100 people, with better risk markers. On the effects on the gut there are mainly animal studies so far. Ready-made kits exist, but you can also put it together yourself.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking 2 sources
Trust score 2 of 5:Plausible Medical treatments
In Japan, inpatient fasting therapy is used for IBS that does not respond to other treatments. The evidence is based on a retrospective analysis. Doing it alone at home is not the same.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking 1 sources
Trust score 2 of 5:Plausible Natural supplements
Binders, antifungal courses and detox protocols against "mould poisoning" have not been tested in controlled studies and can cause harm themselves.
Trust score 2 of 5:Plausible Natural supplements
In the gut, binders also hold back medicines and some nutrients. Studies showing they help with mould symptoms are lacking. More in the chapter on the Herxheimer reaction and detox cures.
Mould: mycotoxins in food and damp in the home no source of its own, score based on judgement
Trust score 2 of 5:Plausible Lifestyle
If you want to try something: one product at a time, decide beforehand which symptom should improve, four to six weeks with a diary, then stop and compare. The trial phases on this site help with that.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. no source of its own, score based on judgement
Trust score 2 of 5:Plausible Lifestyle
Soup made from bones is a good food. As a remedy for the gut wall it has not been studied, and large amounts over a long time make little sense because of possible traces of lead.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 2 sources
Trust score 2 of 5:Plausible Natural supplements
In small studies in healthy people it curbed permeability caused by painkillers or hard training. Not studied in IBS or “leaky gut” without an identifiable cause. Products vary a lot. Avoid if allergic to milk protein.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 5 sources
Trust score 2 of 5:Plausible Natural supplements
Two small studies in healthy people with painkillers or exercise heat. Not studied in people with gut symptoms. It contains zinc, which counts towards your daily amount.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 2 sources
Trust score 2 of 5:Plausible Natural supplements
If at all, only decolourised inner gel, no leaf juice with aloin and no whole-leaf extract. Contradictory small studies in IBS.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 5 sources
Trust score 2 of 5:Plausible Natural supplements
In one small trial it was effective as an add-on to standard therapy in ulcerative colitis; for IBS and the gut wall the effect is unclear. Rare liver injury; check first if you take anticoagulants.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 3 sources
Trust score 2 of 5:Plausible Natural supplements
Butyrate capsules show mixed results in small studies. More in the chapter on short-chain fatty acids; fibre is the better-supported route to more butyrate.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 1 sources
Trust score 2 of 5:Plausible Lifestyle
Bacteria turn it into butyrate, which feeds the gut cells. In a mouse study, fibre even prevented germs from passing through a damaged barrier into the blood. Increase slowly if your gut is sensitive.
The gut barrier 1 sources
Trust score 2 of 5:Plausible Lifestyle
In a small study, the emulsifier carboxymethylcellulose (E466) let bacteria penetrate the protective mucus layer in some individuals. More in the chapter on the mucus layer.
The gut barrier 1 sources
Trust score 2 of 5:Plausible Natural supplements
Zinc plays a role in renewing the gut lining. A benefit is mainly to be expected if a deficiency has been confirmed.
The gut barrier no source of its own, score based on judgement
Trust score 2 of 5:Plausible Lifestyle
Enough fibre from vegetables, legumes and whole grains ensures that bacteria do not switch to the mucus. Variety matters: different fibres feed different species. Increase slowly if your gut is sensitive.
The mucus layer and additives 1 sources
Trust score 2 of 5:Plausible Lifestyle
Carboxymethylcellulose (E466) and polysorbate 80 (E433) are found mainly in ready-made desserts, ice cream and sauces. If you want, you can eat them less often.
The mucus layer and additives 1 sources
Trust score 2 of 5:Plausible Lifestyle
A dish with a few recognisable ingredients usually contains fewer additives and more fibre. That is easier to keep up than checking every E number. Perfection is not needed: if ready-made food is on the table now and then, that is no reason for concern according to current knowledge.
The mucus layer and additives 1 sources
Trust score 2 of 5:Plausible Lifestyle
Nerves and mast cells help control how much mucus the gut makes. Chronic stress and lack of sleep change this in animal models; in humans the data are thin. Recovery is still a cheap, if unspecific, approach.
The mucus layer and additives no source of its own, score based on judgement
Trust score 2 of 5:Plausible Natural supplements
If vegetables and legumes are poorly tolerated, a soluble fibre can help as a supplement to feed the bacteria. Whether this also protects the mucus layer has not been shown in humans. Start slowly to avoid bloating.
The mucus layer and additives no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
Tributyrin is marketed as a precursor of butyrate. Human studies are still lacking.
Butyrate and other short-chain fatty acids no source of its own, score based on judgement
Trust score 1 of 5:Experimental Lifestyle
Fasting clinics have people eat lighter for one or two days beforehand, without coffee, alcohol and lots of sugar, so the transition is gentler and there is less headache. This is practical experience, not a tested method.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking no source of its own, score based on judgement
Trust score 1 of 5:Experimental Lifestyle
During fasting little comes out; that is normal. Plenty of fluid and light movement are usually enough. Laxative salts or enemas are part of some fasting programmes, but should only be used with guidance, because they shift salts in the body.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
During fasting, water and salts are lost in the urine. Salty vegetable broth makes up for this in most healthy people over a few days. Do not take high-dose mineral supplements on your own, especially with kidney or heart disease.
Longer fasting: water fasting, therapeutic fasting and fasting-mimicking no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
They have not been studied in humans for the gut wall; the only study found was open-label without a comparison group. Harmless as a protein source, unproven as a gut remedy.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. 1 sources
Trust score 1 of 5:Experimental Natural supplements
Lab results, but no controlled studies in the gut. Mucilage might delay the absorption of medicines taken at the same time, so as a precaution keep a few hours apart.
The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
There is no supplement for the mucus layer with solid studies in humans. Be wary of products that promise to “rebuild the lining”.
The mucus layer and additives no source of its own, score based on judgement