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. 6 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.
- Level:Intermediate Mould: mycotoxins in food and damp in the home What mould toxins can do in the gut, which dangers are well established, and which tests and cures do not deliver what they promise. Toxins and mouldInflammationTests 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. Community
- Level:Intermediate Longer fasting: water fasting, therapeutic fasting and fasting-mimicking How several days without food remodel the gut microbiota, what studies on therapeutic fasting and fasting-mimicking diets show, and where the risks lie. FastingInflammationBody weight 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 The “leaky gut stack”: colostrum, zinc carnosine, aloe and co. What goes into the typical gut-lining blends, what studies show and where the risks lie. Vitamins and fatty acidsMedicationIBSInflammationExercise 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. Community
Opportunistic pathogens
Germs that only become a problem when the balance is off. 5 chapters – expand
- Level:Intermediate Opportunistic pathogens Germs that are always there and only become a problem when the balance tips. AntibioticsAcid blockersMedicationProbioticsGut infectionsInflammationTests 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 Mouth and gut: how teeth, gums and mouthwash touch the gut flora Every day we swallow billions of mouth bacteria. Usually this is harmless, but with inflamed gums, acid blockers or a weakened gut flora, some of them settle in the gut. Mouth and teethAcid blockersInflammation 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 Biofilms in the gut and “biofilm busters” Bacteria often live in communities with a protective coat. On teeth this is well established, in the gut there are exciting new findings. The products meant to dissolve such films have not been studied there. IBSBile acidsMedicationMouth and teethInflammationAntibiotics 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. Community
- Level:Intermediate Long COVID and the gut: when your stomach won't settle after COVID Diarrhoea, bloating and IBS after a COVID infection: what cohort studies show, what viral remnants in the gut might mean and which treatments have been tested so far. Gut infectionsIBSProbioticsInflammation 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. Community
- 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. 2 chapters – expand
- Level:Beginner Using fermented foods well Sauerkraut, kefir, kimchi: what the studies show and how to include them. Fermented foodsProbioticsHistamineInflammation 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 Gut tests: what they show and what they do not Microbiome analysis, zonulin, IgG, breath test, calprotectin: which tests are worth it. Tests and diagnosticsCoeliac disease and glutenInflammation 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. Community
Gut-brain axis
How stress, sleep and nerves steer digestion. 2 chapters – expand
- Level:Intermediate The vagus nerve: the data line between belly and head The longest cranial nerve tells the brain what is happening in the gut and dampens inflammation. What of this is proven, and what breathing exercises and devices can really do. StressIBSInflammation 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:Intermediate Brain fog and fatigue: when your gut makes your head tired Many people with gut problems feel exhausted and foggy. What studies show, which causes can be checked and what is mere speculation. SleepVitamins and fatty acidsCoeliac disease and glutenInflammationProbioticsTests 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. Community
Digestive function
Stomach acid, bile and enzymes as groundwork for the gut. 1 chapter – expand
- 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.
Small intestine colonisation
When bacteria grow where few belong. 1 chapter – expand
- Level:Expert Where the small intestine meets the colon: ileum, valve and caecum At the end of the small intestine, the gut switches from few to very many bacteria. What the last stretch of small intestine does, how the valve separates the two worlds, and how this transition can be disturbed. Bile acidsDiarrhoeaInflammationTests and diagnostics 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.
Immune system and inflammation
The gut as the body's largest immune organ. 10 chapters – expand
- Level:Intermediate Immune system and inflammation The gut trains your defences and can also upset them unnecessarily. InflammationMediterranean dietFermented foodsSleepTests 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 Eating against silent inflammation What is on your plate influences how agitated your immune system is. InflammationMediterranean dietAdditives 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 IgA: the antibody that keeps the gut clean, and what vitamin A, D and omega-3 have to do with it The body makes more IgA than all other antibodies combined, most of it in the gut. How it is made, why vitamin A matters for it, and what vitamin D and omega-3 really contribute. InflammationVitamins and fatty acidsCoeliac disease and glutenTests 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 SCD, GAPS and the autoimmune protocol: what strict elimination diets can and cannot do Diets with long lists of forbidden foods promise to heal the gut. What studies show about SCD, GAPS and AIP, and why a short, structured test is different from months of avoidance. InflammationMediterranean dietFODMAPPlant 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. Community
- Level:Expert Low-dose naltrexone (LDN): hope, studies and limits An addiction medicine at a very low dose is being tried for Crohn's disease, IBS, fibromyalgia and long COVID. What lies behind it, what studies show and why it belongs in medical hands. MedicationIBSInflammationSleep 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. Community
- Level:Intermediate Skin and gut: what there is to the gut-skin axis Acne, rosacea, eczema, psoriasis: which links to the gut are proven, where a real disease is behind it, and where the hype begins. InflammationCoeliac disease and glutenProbioticsAllergiesAntibiotics 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 Dogs and cats: what pets do to your gut, immune system and nerves Living with animals means sharing microbes, dust and daily life with them. What that means for gut bacteria, allergies, inflammation and the vagus nerve, which of it is only an association, and where pets bring germs along too. AllergiesInflammationStressExerciseGut infectionsAntibiotic resistance 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 PEA (palmitoylethanolamide): the body's own inflammation brake in a capsule A fatty substance the body makes itself to calm mast cells and inflammation. As a supplement it is taken for gut and nerve pain. What studies show and where they are thin. IBSInflammationHistamineDiarrhoea 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 Autoimmune diseases and the gut: Hashimoto's, vitiligo, type 1 diabetes and more When the immune system attacks the body itself, the gut is often involved – as the place where the immune system learns, as a bystander that gets hit, and perhaps as a co-trigger. What is established, what has only been shown in mice, and what people affected can actually do. InflammationCoeliac disease and glutenVitamins and fatty acidsMedicationTests and diagnostics 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. Community
- Level:Intermediate Crohn’s disease and ulcerative colitis: understanding inflammatory bowel disease In Crohn’s disease and ulcerative colitis, the immune system permanently attacks the gut wall. What distinguishes the two, what role genes, smoking, antibiotics and gut microbiota play, why early treatment matters, and what diet, probiotics and faecal transplants really achieve. InflammationDiarrhoeaTests and diagnosticsMedicationAntibioticsNutrientsProbioticsFaecal transplantMediterranean diet Established 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.