Talking turkey about celiac disease and tryptophan

October 29, 2020

But don’t gobble up too much of the Thanksgiving bird just yet

By Amy Ratner, Director of Scientific Affairs

With better timing than most turkeys have at Thanksgiving, research has recently found that people with celiac disease might benefit from tryptophan like that found in the holiday bird.

An international study suggests that tryptophan, an amino acid present in high amounts in turkey, when combined with probiotics, may help those with celiac disease heal and better respond to a gluten-free diet.

The study, published in the journal Science in Translational Medicine, was led by researchers at McMaster University in Canada. Results highlight the potential treatment value of targeting tryptophan metabolism in the gut of those who have celiac disease to better control symptoms that persist despite a gluten-free diet and speed up intestinal healing, according to a press release from the university.

Tryptophan is an essential amino acid, which cannot be produced by the body and needs to be consumed through foods such as poultry, chocolate, bananas and cruciferous vegetables such as broccoli, cabbage and cauliflower.

Tryptophan is necessary for many functions in the body and can be broken down by bacteria in the gut, producing molecules that interact with receptors in the gut lining which control inflammation. Reduced activation of one of these has been implicated in chronic intestinal inflammation, including inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease.

Researchers wanted to determine whether gut bacteria of those with celiac disease breaks down tryptophan in an altered way and what that might mean in developing a treatment. They enrolled three groups of study participants: those with active celiac disease, those who had been on a gluten-free diet for two years and those who did not have celiac disease.

Those with active celiac disease showed lower bacterial metabolism of tryptophan, and their gut microbiome did not appropriately stimulate the pathway that controls inflammation and protects the gut barrier. Partial improvement was seen in study participants who had been on the gluten-free diet for two years.

The study had earlier shown that when mice with the genes for celiac disease were given two strains of lactobacilli, bacteria that breaks down tryptophan, the mechanism that reduces inflammation caused by gluten was activated.

But it may be too early to ask for extra helpings of turkey at Thanksgiving this year. Future clinical studies are needed to investigate tryptophan supplementation in combination with specific probiotics, particularly as a treatment for those who have symptoms despite a gluten-free diet.

You can read more about the study here.