Chapters
Take the gut check and we will sort the chapters by relevance for you.
Opportunistic pathogens
Germs that only become a problem when the balance is off. 1 chapter – expand
- 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
Bacteriophages
Viruses that hunt bacteria and help steer the microbiome. 2 chapters – expand
- Level:Expert Bacteriophages: the hunters in the gut Viruses that only infect bacteria are among the most numerous entities in the gut. What they do there. AntibioticsAntibiotic resistanceFaecal transplantFermented foods 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 Phage therapy: viruses as medicine How phages are used against resistant germs and where the therapy stands today. Antibiotic resistanceGut infections 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.
Microbial diversity
Why many different species keep the gut stable. 5 chapters – expand
- Level:Expert Firmicutes, Bacteroidetes and body weight Does your gut microbiota make you fat? What is behind the much-quoted bacterial ratio. Body weightPlant diversityTests 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.
- 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.
Gut-brain axis
How stress, sleep and nerves steer digestion. 1 chapter – expand
- Level:Expert POTS and hypermobility: when circulation and connective tissue drag the gut along People with hypermobile joints (hEDS, hypermobility spectrum) or a racing heart on standing (POTS) have gut symptoms strikingly often. What studies show, what to make of the much-quoted "trifecta" with MCAS, and what helps. IBSConstipationExerciseHistamine 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
Digestive function
Stomach acid, bile and enzymes as groundwork for the gut. 1 chapter – expand
- Level:Expert Bile, lipase and lecithin: what fat digestion really needs Digesting fat takes more than bile: the enzyme lipase from the pancreas, bile as a washing-up liquid and an intact gut wall. What bile salt, TUDCA, ox bile and lecithin capsules actually show, and what choline is really needed for. Bile acidsNutrientsMedicationTests 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.
Small intestine colonisation
When bacteria grow where few belong. 4 chapters – 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.
- Level:Expert Why SIBO comes back: the cleaning wave, underlying causes and prokinetics After successful treatment, small intestinal bacterial overgrowth returns in many people. What the small intestine’s cleaning wave has to do with it, which causes are worth looking for, and what drugs that stimulate gut movement can do. BloatingAntibioticsAcid blockersMedicationConstipation 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:Expert SIBO treatments compared: rifaximin, herbs, elemental diet and faecal transplant Antibiotic or herbs, a liquid formula diet or a faecal transplant: what studies show for each option, where the evidence is thin and what people with SIBO report. AntibioticsBloatingProbioticsFaecal transplantTests 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:Expert Hydrogen sulfide and methane: the other gases in the gut Methane is linked to constipation, hydrogen sulfide to diarrhoea. Which microbes produce them, what a three-gas breath test can and cannot show, and what to make of low-sulfur diets and bismuth. ConstipationDiarrhoeaBloatingTests and diagnosticsAntibiotics 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
Immune system and inflammation
The gut as the body's largest immune organ. 4 chapters – expand
- Level:Expert DAO: the enzyme that intercepts histamine from food Where DAO is made, why it can be lacking, which medicines inhibit it, and what DAO capsules and sprouts can do. HistamineMedicationAlcoholFermented foods 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: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:Expert Mast cells: alarm cells in the gut, histamine and the disputed MCAS Mast cells sit just beneath the gut lining and release histamine when alarmed. What they have to do with IBS and stress, and why mast cell activation syndrome is so often wrongly diagnosed. HistamineIBSStressAllergies 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: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