![Recognize protein deficiency and counteract it with this diet](https://tipsforwomens.org/wp-content/uploads/2024/01/Recognize-protein-deficiency-and-counteract-it-with-this-diet.jpeg)
Many protein-rich foods contain the essential amino acid tryptophan. According to recent findings, it appears to be converted by bacteria in the digestive tract in such a way that it promotes inflammation and prepares the immune system for arthritis.
A new study involving experts at the University of Colorado Anschutz Medical Campus used a model of collagen-induced arthritis to examine how changes in tryptophan and indole metabolism correlate with the disease. The results are published in the “Journal of Clinical Investigation”.
What is tryptophan?
Tryptophan, which is found in many protein-rich foods such as meat, fish, dairy products and certain seeds and nuts, fulfills a variety of functions in the body. According to the researchers, the essential amino acid supports, among other things, the development of proteins, muscles, enzymes and neurotransmitters, the messenger substances of the nervous system.
Tryptophan cannot be produced by the body itself, but is absorbed through food, the team adds. The experts investigated to what extent tryptophan can support the development of rheumatoid arthritis.
Influence on inflammation
“It is known that the microbiome – the bacteria in our intestines – can break down tryptophan into byproducts. Some of these byproducts are anti-inflammatory, but we also found some inflammatory consequences of these products,” reports study author Dr. Kristine Kuhn in a press release.
The researchers have now shown for the first time which products contribute to inflammation and how they do this. The new study builds on various observations made in people with spondyloarthritis.
In this disease, which is closely related to rheumatoid arthritis, it was found that changes in the intestinal flora are associated with increased production of the byproduct indole. Indole is produced by bacteria from tryptophan. Similar changes have already been observed in mice in arthritis studies, says Dr. Kuhn.
Indole conveys the connection
The animals were treated with antibiotics to destroy their intestinal flora. The result was that the mice did not develop arthritis and had no indole. This raised the question among experts: what happens if the animals have a microbiome and eat a diet low in tryptophan?
It turned out that the animals’ intestinal flora could not break down tryptophan into indole, and the mice did not develop arthritis. The researchers were able to show in two different ways that the intestinal flora breaks down tryptophan into indole.
“We found that in the presence of indole, the mice develop autoreactive T cells that are more inflammatory. They have fewer regulatory T cells, which help keep the immune system balanced, and they begin to develop antibodies that are more pathogenic. We found that the antibodies are more inflammatory in the presence of indole,” explains Dr. Kuhn.
New therapeutic approach
The researchers conclude that blocking indole formation could be a possible therapeutic approach for rheumatoid arthritis and spondyloarthritis.
The aim is to find the right path for the body’s own tryptophan. If tryptophan hits body cells, it is more likely to be broken down into anti-inflammatory products than if it hits bacterial cells and triggers inflammation, explains Dr. Kuhn.
So the question the experts asked themselves was: How can you maintain the balance so that tryptophan takes the anti-inflammatory route, and how can you manipulate the gut bacteria in such a way that this balance is changed?
Mediterranean diet for the intestinal flora
According to the researchers, nutrition in particular could play an important role. A Mediterranean diet rich in plant-based fiber and lean meat appears to shift the intestinal flora to a healthier state so that the anti-inflammatory properties of tryptophan are retained. (as)