Chapters
Take the gut check and we will sort the chapters by relevance for you.
Gut barrier
The gut lining as the border between gut contents and the body. 3 chapters – expand
- Level:Beginner The gut barrier A layer of cells thinner than a hair separates the gut contents from the body. What keeps it tight. FibreAlcoholAdditivesCoeliac disease and glutenInflammationTests and diagnostics Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Intermediate The mucus layer and additives Why the distance between bacteria and the gut wall matters and what emulsifiers have to do with it. AdditivesFibreInflammation Plausible How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Intermediate Butyrate and other short-chain fatty acids What gut bacteria make from fibre and what the body needs these substances for. Short-chain fatty acidsFibreInflammationPlant diversity Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
Opportunistic pathogens
Germs that only become a problem when the balance is off. 1 chapter – expand
- Level:Intermediate Gut and cancer: what the gut microbiota protects against, what harms, and why it matters in cancer treatment Fibre and its bacteria protect against colorectal cancer, while some bacteria damage the genome. Why colorectal cancer is rising in younger people, which germs travel along in tumours, what Helicobacter has to do with stomach cancer, and why the gut microbiota helps decide whether immunotherapy works. FibreInflammationAntibioticsProbioticsTests and diagnosticsMouth and teethFaecal transplantBile acids Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
Microbial diversity
Why many different species keep the gut stable. 8 chapters – expand
- Level:Beginner For everyone Your gut in ten minutes Who lives there, what do they do, and why is balance more important than individual germs? FibrePlant diversityFermented foodsAntibioticsExerciseTests and diagnostics Well supported How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Beginner Building microbial diversity Why many different species keep the gut stable and how to rebuild after antibiotics. Plant diversityFermented foodsProbioticsAntibioticsFibre Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Expert Prebiotics beyond inulin: HMOs, arabinogalactan, polyphenols Lesser-known food for the gut flora: what studies show and which polyphenols are best researched. PrebioticsFibrePlant diversityShort-chain fatty acidsIBS Plausible How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Expert Anaerobic gut bacteria: why the good ones do not fit in a capsule The most important gut bacteria cannot tolerate oxygen. What makes them thrive, and why you can barely swallow them. ProbioticsShort-chain fatty acidsFibreFaecal transplant Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Expert The second-meal effect: why dinner helps decide your blood sugar in the morning Lentils at breakfast lower blood sugar at lunch, whole barley kernels in the evening lower it at breakfast. How this works, and what role gut bacteria play. FibreShort-chain fatty acidsBlood sugarBody weight Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Expert GLP-1 from the gut: what bacteria do and what “natural Ozempic” cannot do Weight-loss injections mimic a hormone that your own gut wall also makes, stimulated among other things by bacteria. How this pathway works and why it does not have the same effect as the drug. Short-chain fatty acidsFibreBody weightBlood sugar Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Intermediate Carnivore and keto: less gas, but at what cost? Why many people feel less bloated on an all-meat or ketogenic diet, what this does to gut bacteria, and why experts do not recommend it for gut health. FibreShort-chain fatty acidsPlant diversityBloatingBody weight Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open. Community
- Level:Beginner For everyone Big effect, small budget: low-cost measures for your gut What demonstrably helps the gut often costs almost nothing: slow breathing, cooled potatoes, potato starch from the supermarket, legumes, psyllium, kiwis, a stool in front of the toilet. An overview of how well each is supported, what it costs and where you can skip expensive detours. FibreExerciseStressPrebioticsFermented foodsConstipationBloatingShort-chain fatty acids Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
Digestive function
Stomach acid, bile and enzymes as groundwork for the gut. 4 chapters – expand
- Level:Beginner Constipation: more than too little fibre Kiwifruit, psyllium, pelvic floor and methane: what is behind sluggish digestion. ConstipationFibreExerciseMedication Well supported How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Intermediate Oxalate, salicylate, lectins: hidden culprits or internet myth? Where these plant compounds really cause problems, such as kidney stones, after bowel surgery or with raw beans, and why lists against "oxalate dumping" and lectins tend to harm the gut. Toxins and mouldPlant diversityFibreMedication Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open. Community
- Level:Beginner Diverticula, haemorrhoids and fissures: what can go wrong at the end of the gut Three common problems in the lower gut that people rarely talk about. Why nuts and seeds are fine with diverticula, why mild diverticulitis often heals without antibiotics, and what your phone on the toilet has to do with haemorrhoids. FibreConstipationInflammationAntibiotics Well supported How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open.
- Level:Beginner Bloating and fullness: gas that will not move on Why the belly distends even though there is rarely too much gas – and what really helps. BloatingIBSFODMAPSweetenersFibreExercise Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open. Community
Small intestine colonisation
When bacteria grow where few belong. 1 chapter – expand
- Level:Intermediate Prebiotics that build up gently Why some fibres cause bloating and others feed the gut microbiota gently. FibreBloatingFODMAPShort-chain fatty acidsIBSPrebiotics Promising How we rate the evidence Established Recommended in medical guidelines or supported by several consistent meta-analyses of randomised human studies. Well supported Several randomised studies in humans with largely consistent results. Promising Single randomised or controlled studies in humans, not yet independently confirmed — or many consistent observational studies. Plausible Two cases: first observational or pilot studies with small samples — or a settled basis that is not in dispute, such as movement, sleep or meal pauses. But not tested in humans for symptoms. Experimental Barely studied in humans. Mainly lab and animal studies or theoretical reasoning; whether it helps is open. Community