Common beliefs about the gut, briefly put into context. Each card links to the chapter with the evidence.
Not proven
A genuine Herxheimer reaction occurs almost only with antibiotics against spirochaetes and lasts hours. It is not proven for Candida, gut or parasite protocols. Reading worsening as healing overlooks side effects.
Evidence in the chapter: Herxheimer reaction, die-off and toxins
Not proven
In mice there was a link; in humans large studies show no clear pattern. Both groups contain hundreds of species with very different properties.
Evidence in the chapter: Firmicutes, Bacteroidetes and body weight
Not proven
Evidence in humans is lacking. In the lab, vitamin C is even on the list of substances that inhibit the histamine-degrading enzyme DAO. That lab value, however, may be a measurement artefact: vitamin C consumes the hydrogen peroxide through which DAO activity is measured. In humans, neither benefit nor harm is established.
Evidence in the chapter: DAO: the enzyme that intercepts histamine from food
Not proven
The same sample can give different results at different providers, and there are no reference ranges for most values. Targeted tests for pathogens or inflammation, on the other hand, are useful.
Evidence in the chapter: Gut tests: what they show and what they do not
Not proven
There is no evidence for this. Products can be contaminated with lead, and activated charcoal also binds medicines.
Evidence in the chapter: Herxheimer reaction, die-off and toxins
Not proven
Unproven. Genuine MCAS is rare and needs lab evidence during an attack. Professional societies warn that the diagnosis is often made without this evidence, so other, treatable causes are overlooked.
Evidence in the chapter: Mast cells: alarm cells in the gut, histamine and the disputed MCAS
Not proven
Unproven. The test has been studied almost only by the group that co-developed it, there is no uniform cut-off, and it does not show where in the gut the gas is produced. An abnormal result is a clue, not a diagnosis.
Evidence in the chapter: Hydrogen sulfide and methane: the other gases in the gut
Not proven
Unproven. The most cited study was retrospective and not randomised. For single substances such as allicin or oregano oil there are no studies in SIBO. Herbal remedies can also have side effects and interactions.
Not proven
Unproven. There is not a single study on this term. Real oxalate problems are calcium oxalate stones and oxalate excess with poor fat digestion. They are detected with urine tests, not by symptoms after a change of diet.
Evidence in the chapter: Oxalate, salicylate, lectins: hidden culprits or internet myth?
Not proven
Unproven. Raw or undercooked kidney beans can indeed cause poisoning. But soaking and thorough cooking inactivate lectins, and according to EFSA properly prepared food poses no risk. Pulses are linked to better health.
Evidence in the chapter: Oxalate, salicylate, lectins: hidden culprits or internet myth?
Not proven
Unproven. Colostrum and zinc carnosine curbed permeability caused by painkillers or hard training in healthy people. For none of the ingredients is it shown that they help people with gut symptoms by tightening the gut wall. Long-term zinc can cause copper deficiency.
Evidence in the chapter: The “leaky gut stack”: colostrum, zinc carnosine, aloe and co.
Not proven
Unproven. Biofilms on the gut lining exist, and in some people with IBS they are even common. No controlled study shows that NAC, enzymes or EDTA dissolve them in the gut and make protocols more effective. Enzymes such as nattokinase, on the other hand, can promote bleeding.
Evidence in the chapter: Biofilms in the gut and “biofilm busters”
Not proven
Unproven. The liver still makes enough bile. In one study, quality of life after surgery improved regardless of how much fat people ate. If large, fatty meals give you diarrhoea, spread the fat out rather than cutting it.
Evidence in the chapter: Life without a gallbladder: diarrhoea, fat and symptoms after surgery
Know a myth that is missing here? Suggest it