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 | 14 | 5 | ||
| Opportunistic pathogens | 1 | 3 | 9 | 5 | 10 |
| Bacteriophages | 2 | 2 | |||
| Microbial diversity | 2 | 4 | 12 | 13 | 5 |
| Gut-brain axis | 3 | 5 | 7 | 2 | |
| Digestive function | 1 | 8 | 14 | 10 | 9 |
| Small intestine colonisation | 1 | 1 | 2 | 7 | 3 |
| Immune system and inflammation | 1 | 5 | 14 | 7 | |
| Total | 5 | 20 | 50 | 72 | 43 |
Tap a number to see the tips below. Darker cells contain more tips.
Digestive function · Clear selection
Trust score 5 of 5:Established Natural supplements
The Cochrane review shows: in children, zinc shortens the duration and stool volume of acute diarrhoea. The benefit is greatest in regions with widespread malnutrition, and smaller in industrialised countries.
Diarrhoea: understand it, place it and react the right way 1 sources
Trust score 4 of 5:Well supported Natural supplements
Once a deficiency is confirmed in the blood, it can usually be corrected with high-dose B12 tablets, because a small part is absorbed even without stomach acid and without the transport protein. Dose and follow-up are decided by your doctor; without a proven deficiency, taking it as a precaution is not supported.
Acid blockers (PPIs): what they change in the gut and how to stop them properly 1 sources
Trust score 4 of 5:Well supported Natural supplements
Soluble fibre is recommended in the guideline. Increase slowly and drink enough with it.
Constipation: more than too little fibre 2 sources
Trust score 4 of 5:Well supported Natural supplements
In a meta-analysis of seven trials of fibre supplements for haemorrhoids, the risk of persisting symptoms fell by 47 per cent and of bleeding by half. Fibre also helps with fissures because stools become softer. Start low and drink plenty.
Diverticula, haemorrhoids and fissures: what can go wrong at the end of the gut 1 sources
Trust score 4 of 5:Well supported Natural supplements
Take iron on an empty stomach where possible, at least one hour before or two hours after a meal, with a little vitamin C. Tea, coffee, milk, wholegrain and pulses strongly inhibit absorption. If that irritates your stomach, taking it with food is better than not taking it at all. Every other day instead of daily is often better: a dose raises hepcidin, which regulates iron balance, so less is absorbed the next day. With inflammation, higher ferritin limits are needed to detect a true deficiency. High-dose iron without a deficiency can cause gut complaints.
Nutrient deficiency in gut problems: when food no longer arrives 2 sources
Trust score 4 of 5:Well supported Natural supplements
Anyone eating a purely plant-based diet, or whose ileum is damaged or removed, needs vitamin B12. If absorption through the gut is disturbed, it is injected or taken orally in high doses (1000 to 2000 µg per day, of which about one percent is absorbed even without the ileum). Which route is preferred varies by country and cause, and the level is monitored. Metformin and long-term acid blockers lower the level further.
Nutrient deficiency in gut problems: when food no longer arrives 3 sources
Trust score 4 of 5:Well supported Natural supplements
The level is measured via 25-OH vitamin D, not estimated. With a proven shortage, a usual dose is enough. The licensing authorities advise against megadoses, because they bring no more and can harm.
Nutrient deficiency in gut problems: when food no longer arrives 2 sources
Trust score 4 of 5:Well supported Natural supplements
High-dose supplements without a proven deficiency rarely do any good and can harm, for example vitamin A in pregnancy or zinc for copper balance. A hair analysis is not suitable for detecting a nutrient deficiency.
Nutrient deficiency in gut problems: when food no longer arrives 3 sources
Trust score 4 of 5:Well supported Natural supplements
After an iron tablet, the hormone hepcidin slows absorption for about a day. In studies with iron-deficient women, iron taken every other day was absorbed better than daily or twice daily. Fewer tablets also means less iron irritating the gut. Agree the schedule with your doctor.
When the supplement itself is the problem: iron, magnesium, excipients and more 2 sources
Trust score 3 of 5:Promising Natural supplements
For the first weeks after stopping, antacids or alginates, which form a foam on top of the stomach contents, help when needed. The Canadian deprescribing guideline names such remedies for relieving symptoms in this phase.
Acid blockers (PPIs): what they change in the gut and how to stop them properly 1 sources
Trust score 3 of 5:Promising Natural supplements
Peppermint oil capsules ease abdominal pain and improve overall wellbeing in IBS. For the bloating itself the evidence is weaker, and the studies are of low quality. With reflux, peppermint oil can make heartburn worse.
Trust score 3 of 5:Promising Natural supplements
It has been recommended in a guideline for the first time, though based on few studies. If your kidney function is reduced, check with your doctor first.
Constipation: more than too little fibre 1 sources
Trust score 3 of 5:Promising Natural supplements
In acute infectious diarrhoea, probiotics shortened the symptoms by about a day on average in the Cochrane review. The effect depends strongly on the strain and is less clear in infants. No substitute for fluid.
Diarrhoea: understand it, place it and react the right way 1 sources
Trust score 3 of 5:Promising Natural supplements
Anyone who tolerates lactose poorly can take lactase tablets with food. Most adults tolerate 12 to 15 g of lactose anyway; symptoms appear only above that.
Diarrhoea: understand it, place it and react the right way 1 sources
Trust score 3 of 5:Promising Natural supplements
In a study of 8 healthy people, the enzyme taken with a bean meal reduced gas production and bloating. It only helps with galactans, that is legumes and cabbage, not with other FODMAPs. Lactase tablets, correspondingly, only work on milk sugar.
Digestive enzymes from mouth to colon: who breaks down what 1 sources
Trust score 3 of 5:Promising Natural supplements
Form a layer on top of the stomach contents and can relieve heartburn after meals. Available from pharmacies without prescription in many countries.
Heartburn and reflux no source of its own, score based on judgement
Trust score 3 of 5:Promising Natural supplements
Acid-binding tablets or gels act quickly, but only for a short time. For occasional heartburn they are often enough. If you need them regularly, that is a reason to talk to your doctor. Some contain aluminium, magnesium or calcium and affect bowel movements and the absorption of other medications.
Heartburn and reflux no source of its own, score based on judgement
Trust score 3 of 5:Promising Natural supplements
They can help when you are about to eat a larger amount of lactose. The evidence is mixed; for most people, controlling the amount is enough.
Lactose, fructose, gluten: making sense of intolerances no source of its own, score based on judgement
Trust score 3 of 5:Promising Natural supplements
In children in countries with frequent diarrhoea, zinc shortens the duration and stool volume. But high-dose zinc over months disturbs copper absorption and can itself trigger a deficiency.
Nutrient deficiency in gut problems: when food no longer arrives 1 sources
Trust score 3 of 5:Promising Natural supplements
It makes stool softer and smoother. The guideline conditionally recommends fibre for chronic constipation. Increase slowly and drink plenty.
Trust score 3 of 5:Promising Natural supplements
In a meta-analysis of 5 trials with 578 people, capsules with both oils improved symptoms. The trials were small and of low quality. Peppermint oil can worsen heartburn.
Sensitive stomach: fullness, upper abdominal pain and Helicobacter 2 sources
Trust score 3 of 5:Promising Natural supplements
A mix of six plants improved fullness, early satiety and upper abdominal pain after 4 and 8 weeks in an analysis of 2 trials, with side effects like placebo. The trials were supported by the manufacturer.
Sensitive stomach: fullness, upper abdominal pain and Helicobacter 1 sources
Trust score 3 of 5:Promising Natural supplements
If magnesium causes soft stools, it often helps to lower the amount or spread it over two portions with meals. Magnesium oxide and larger amounts of citrate have a particularly strong laxative effect. In constipation, on the other hand, you can use this effect deliberately.
When the supplement itself is the problem: iron, magnesium, excipients and more 2 sources
Trust score 2 of 5:Plausible Natural supplements
Psyllium husk binds water and makes the stool firmer.
Bile acids: when bile causes diarrhoea no source of its own, score based on judgement
Trust score 2 of 5:Plausible Natural supplements
Choline is not a digestive aid. It acts on the liver’s fat metabolism, and a benefit is proven only where a deficiency was measurable, for example with long-term artificial nutrition. For healthy people eating normally there is no reason to supplement it.
Bile, lipase and lecithin: what fat digestion really needs 2 sources
Trust score 2 of 5:Plausible Natural supplements
Simeticone is meant to dissolve gas bubbles and is in many over-the-counter products. The evidence is weak: in newer studies it served more as a comparison, against which other preparations did slightly better. Possible as a trial, but no established benefit.
Trust score 2 of 5:Plausible Natural supplements
In a study of 18 gluten-sensitive people, an enzyme from Aspergillus niger broke down most of 0.5 g of gluten while still in the stomach. That is a small amount, and in coeliac disease partial breakdown is not enough. If you have coeliac disease, stay on a strict gluten-free diet.
Digestive enzymes from mouth to colon: who breaks down what 1 sources
Trust score 2 of 5:Plausible Natural supplements
Over-the-counter blends of plant and fungal enzymes are advertised against fullness. Without proven pancreatic insufficiency, there are no good studies for them. In genuine insufficiency, the prescription pancreatic enzymes are dosed much higher. Over-the-counter blends do not replace them; the dose is adjusted to meals by a doctor.
Digestive enzymes from mouth to colon: who breaks down what 1 sources
Trust score 2 of 5:Plausible Natural supplements
Warm sitz baths are often recommended for fissures and haemorrhoids. In a small study after fissure surgery they eased burning but not pain. A few minutes in warm water without additives does no harm; avoid hot baths and irritating bath additives.
Diverticula, haemorrhoids and fissures: what can go wrong at the end of the gut 2 sources
Trust score 2 of 5:Plausible Natural supplements
Psyllium husk binds water and can firm up stools. There are no specific studies for diarrhoea after gallbladder removal, but it is an easy, well-tolerated thing to try.
Life without a gallbladder: diarrhoea, fat and symptoms after surgery no source of its own, score based on judgement
Trust score 2 of 5:Plausible Natural supplements
The body converts part of vitamin C into oxalate. In case reports, high-dose vitamin C contributed to oxalate kidney damage. If you have had kidney stones or have reduced kidney function, discuss high doses with your doctor.
Oxalate, salicylate, lectins: hidden culprits or internet myth? 1 sources
Trust score 2 of 5:Plausible Natural supplements
They do not replace a medical check-up. In real pancreatic insufficiency, prescribed enzymes at a sufficient dose are needed.
Stomach acid, bile and enzymes no source of its own, score based on judgement
Trust score 2 of 5:Plausible Natural supplements
Split creatine into two smaller portions instead of 10 grams at once. Choose protein powders without sugar alcohols and inulin, and try mixing with water instead of milk.
When the supplement itself is the problem: iron, magnesium, excipients and more 1 sources
Trust score 1 of 5:Experimental Natural supplements
Bile salts or ox bile are sometimes taken against supposedly “thick bile”. In bile acid diarrhoea, extra bile can worsen symptoms, and there are no studies showing a benefit. Herbal bitters meant to stimulate bile flow are also hardly studied. Clarify the cause first.
Bile acids: when bile causes diarrhoea no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
They are sold for fat digestion problems and for better bile flow. With an intact pancreas and normal bile production there are no studies for this, and extra bile acids can worsen diarrhoea. Clarify the cause first, then treat.
Bile, lipase and lecithin: what fat digestion really needs 4 sources
Trust score 1 of 5:Experimental Natural supplements
Advertising calls lecithin an emulsifier for fat digestion. Human studies for this are lacking, and in the gut lecithin is split by a phospholipase. In ulcerative colitis small studies were positive, the large independent study of 2024 was negative.
Bile, lipase and lecithin: what fat digestion really needs 3 sources
Trust score 1 of 5:Experimental Natural supplements
Herbal teas of caraway, anise and fennel are traditional and are often experienced as soothing. Reliable controlled studies are lacking; fennel has only been studied in a different context (recovery after abdominal surgery). A capsule of peppermint and caraway oil has slightly better, though still thin, data for stomach complaints.
Trust score 1 of 5:Experimental Natural supplements
These are often recommended, but there are no solid studies in gastroparesis. If you like and tolerate ginger tea, you can drink it; it does not replace treatment. Large amounts of bulking agents and high-fibre powders tend to be unfavourable for a sluggish stomach.
Gastroparesis: when the stomach empties too slowly no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
They are often sold as a "replacement" for the missing gallbladder. But the liver still makes enough bile, and extra bile acids can worsen diarrhoea, because they are exactly what draws water into the colon. Studies for this use are lacking.
Life without a gallbladder: diarrhoea, fat and symptoms after surgery no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
After oil cleanses with olive oil and lemon juice, greenish “stones” appear in the stool. A lab examined such objects: they consisted of fatty acids, a kind of soap made from the oil itself, without cholesterol or bile pigment. Real stones are not flushed out this way, and if stones are present, strong stimulation of the gallbladder can trigger a colic.
Pressure under the right ribs: bile, liver and gallstones 1 sources
Trust score 1 of 5:Experimental Natural supplements
Bitters are traditionally used to stimulate gastric juice and bile. Good human studies are lacking.
Stomach acid, bile and enzymes no source of its own, score based on judgement
Trust score 1 of 5:Experimental Natural supplements
None of these methods has been tested for digestive symptoms. If you think you have too little acid, have the cause clarified, for example gastritis or Helicobacter, instead of swallowing acid. Do not try it with heartburn, ulcers or anti-inflammatory painkillers.
The digestive chain: how stomach acid, bile and pancreas set each other off no source of its own, score based on judgement