Helminths and Crohn's disease: new data

Parasitic worms are able to protect people from intestinal diseases

Polit.<url> based on the materials of Science: Parasitic worms may prevent Crohn's disease by altering bacterial balance

A new study has shown that some parasitic worms can prevent Crohn's disease and other inflammatory bowel diseases in people in whose digestive system they live. Scientists believe that the parasite does this by affecting the composition of bacteria in the intestine. It displaces those species that contribute to inflammation. The results of the study may lead to the emergence of new treatments that will mimic the effects of a parasitic worm.

One of the co-authors of the study, immunologist Ken Cadwell from the New York University School of Medicine, says that scientists have noticed a lower incidence of inflammatory bowel diseases in a number of countries where helminths are very common. Conversely, in the developed countries of Europe and the USA, where parasitic diseases are very rare, inflammatory bowel diseases, such as Crohn's disease, are more common.

In the experiment, Cadwell and his colleagues used laboratory mice with the same genetic defect that occurs in many patients with Crohn's disease. Due to a certain mutation in such people, the cells of the intestinal mucosa secrete less mucus that protects against the effects of bacteria. In mice, as in people with this feature, representatives of the genus Bacteroides, which cause inflammation, began to multiply intensively among the bacteria living in the intestine. The researchers then infected the experimental mice with parasites from the roundworm group. It turned out that this was followed by a decrease in the number of inflammation–related bacteria in the digestive system and an increase in the number of another group of bacteria - Clostridiales. The work of intestinal cells secreting mucus, which serves as a breeding ground for this group of bacteria, has also normalized.

To test whether there is such an effect in humans, the researchers studied two groups of the Malaysian population. Intestinal parasites are rare among residents of the capital Kuala Lumpur, but representatives of the peoples living in rural areas, united under the name "orang-asli", are usually infected with parasites. The study showed differences in the bacterial flora of the intestine in representatives of these two groups. The metropolitan residents were dominated by Bacteroides bacteria, and the Orang-asli – Clostridiales.

Attempts to use parasitic worms in the treatment of Crohn's disease have already been made. But a recent clinical trial in which patients took a solution containing parasite eggs was aborted due to clearly unsuccessful results. Ken Cadwell believes that exposure to parasite worms can be effective for the group of patients with Crohn's disease who have this genetic mutation. Among all patients, they make up about 30%. Scientists also believe that it will be useful to find out how parasites cause changes in the composition of bacteria, so that they can then synthesize the substances they use for this and get the same effect in a safer way.

The results of the study are published in the journal Science (Ramanan et al., Helminth infection promotes colonization resistance via type 2 immunity).

Portal "Eternal youth" http://vechnayamolodost.ru  15.04.2016