The Leaky Gut; is the "leaky" gut a plausible hypothesis?
Mainstream medical professionals do not recognize the leaky gut as a real condition, however, there is quite a bit of scientific evidence that leaky gut does exist and may be associated with multiple health problems. Nevertheless, multiple studies suggest and medical professionals do agree that increased intestinal permeability exists in certain chronic diseases like Celiac disease, Diabetes, Crohn’s disease which is a chronic digestive disorder characterized by persistent inflammation of the intestinal tract and Irritable Bowel Syndrome which is also a digestive disorder characterized by both diarrhea and constipation. Interestingly, animal studies on celiac disease, type 1 diabetes and IBS have identified increased intestinal permeability prior to the onset of disease. This evidence supports the theory that leaky gut is involved in the development of disease. (1)
There is sufficient evidence to demonstrate that leaky gut syndrome exists but the claim that leaky gut is the root of modern health problems has yet to be proven by science. (1)
Animal models are a good surrogate for human studies. All species, including horses, suffer from alterations that increase intestinal permeability including poultry, porcine, rodent, and human. These alterations, also known as “leaky gut,” may lead to severe disease as the normal intestinal barrier becomes compromised and can no longer protect against harmful luminal contents including microbial toxins and pathogens. (2)
‘Leaky gut’ syndrome, long-associated with celiac disease, is described as an increase in the permeability of the intestinal mucosa, which could allow bacteria, toxic digestive metabolites, bacterial toxins, and small molecules to ‘leak’ into the bloodstream. (3)
It’s plausible that any gluten that finds its way into the blood circulation would equally cause an immunological response. Celiac disease is an autoimmune disease in which eating foods that contain the protein gluten—found in wheat, barley, and rye—triggers the white blood cells to attack the lining of the small intestine, ultimately eroding it until it's worn smooth. The lining of the small intestine is made up of tiny, finger-like projections called villi, which help us digest food. The autoimmune reaction in celiac disease attacks these villi, which is what leads to symptoms and complications. Blood tests usually represents the first step in the diagnosis process screening blood for high levels of antibodies associated with the body's reaction to gluten in the diet. (4)
References:
Is Leaky Gut Syndrome a Real Condition? An Unbiased Look (2017) https://www.healthline.com/nutrition/is-leaky-gut-real
Alterations in Intestinal Permeability: The Role of the “Leaky Gut” in Health and Disease (2017) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6467570/
Leaky Gut, Leaky Brain? (2018) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6313445/
An Overview of Celiac Disease (2020) https://www.verywellhealth.com/celiac-disease-overview-4014748