It is not true that people cannot digest gluten


Original article (in Slovenian) was published on 28/09/2023; Author: Nina Rozman

Jernej Dolinšek, head of the paediatric clinic at University Medical Centre Maribor and an expert in gastrointestinal diseases, explained that the human body has enzymes to break down gluten, so humans can digest it.

On 29 August, the web portal Planet Lepote reported in an article on “anti-nutrients” to avoid that gluten “cannot be digested by any human”. The claim was attributed to Tom O’Bryan, a certified American chiropractor and author of The Autoimmune Fix.

O’Bryan is a physician in internal medicine and infectious diseases and a chiropractor, according to the American Board of Medical Specialties. The website of the American Institute of Functional Medicine, where he is employed, states that his research focuses on the health impact of wheat and the development of autoimmune intestinal diseases.

He is also the mastermind behind the Gluten Summit, a series of 29 interviews with experts and opinion leaders on gluten-related disorders, nutrition, and healthy living. O’Bryan offers a $47 digital package on the “summit” website allowing users to downlaod and stream these interviews.

The interviews are hosted by, a website founded by O’Bryan where he also markets supplements for “optimal gluten digestion”.

Jernej Dolinšek, head of the paediatric clinic at the University Medical Centre Maribor and an expert in gastrointestinal diseases, explained to that gluten is a combination of two types of proteins; in wheat these are gliadins and glutenins. When these proteins combine, we speak of gluten.

“Humans can break down gliadin and glutenin, which make up the gluten in wheat,” Dolinšek said. Mammals and many other animals can digest the proteins that make up gluten because they have enzymes to break them down. “These are populist, perhaps sometimes overly simplistic, claims that humans cannot break down gluten.”

He also pointed to the dangers of eating gluten, for example for people allergic to wheat or with coeliac disease. Their immune cells already recognise gluten as harmful before it is broken down, so they attack their own bodies, he explained. But immune reactions “have nothing to do with whether or not a person can break down gluten”.

Gluten sensitivity should not be equated with an inability to digest gluten, he stressed. Dolinšek illustrated the difference between gluten sensitivity and the inability to digest gluten with the example of a coeliac patient who has enzymes to break down the proteins that make up gluten, but whose immune system triggers an immune reaction to gluten.

The veracity of the claim that people cannot digest gluten was also denied by the National Institute of Public Health (NIJZ), which supported this by linking to an article on, a national portal dedicated to informing people about the benefits of a healthy diet that provides credible information about diets and that it operates together with the Nutrition Institute.

The article for example explains that gluten is “completely harmless” for the vast majority of people. The protein in gluten is “quite low in nutritional value” and is therefore not a necessary part of a healthy diet, but many whole-grain cereals containing gluten are rich in vitamins, minerals and dietary fibre that are beneficial to health.

The NIJZ further explained that the term “anti-nutrient” referred to in the Planet Lepote article is used in scientific literature and research and refers to “naturally occurring compounds in foods that can interfere with the body’s intake or use of nutrients”.

They stressed that compounds containing “anti-nutrients” are not harmful and need not be avoided, but that their excessive consumption can lead to nutritional deficiencies such as vitamin deficiencies and other health problems.

In 2020, in a study published in the peer-reviewed scientific journal International Journal of Molecular Sciences, Spanish biochemists and molecular biologists presented an analysis of 151 stool samples from non-coeliacs aged zero to 25+ years. They found that humans can digest gluten from birth.

In response to a question from about his claim, O’Bryan reiterated that science confirms that “no human being can digest wheat” and that it “causes inflammation in every human being”. He promised to send links to studies confirming this, but he did not.

The claim that “no human being can digest gluten” is false.