The Western diet can damage these immune cells in the intestine

New studies in mice and humans show that eating a Western-style diet impairs the gut’s immune system in ways that can increase the risk of infection and inflammatory bowel disease.

This study shows that a sugar- and fat-rich diet damages Paneth cells, the immune cells in the intestine that help control inflammation.

If Paneth cells are not functioning properly Intestinal immune system It is prone to inflammation, is at risk for inflammatory bowel disease, and impairs effective control of the disease-causing microorganisms.

Survey results published in Cell hosts and microorganismsBy restoring normal Paneth cell function, it opens up new approaches to regulating intestinal immunity.

“Inflammatory bowel disease has historically been a problem primarily in Western countries, such as the United States, but it is becoming more common worldwide as more people adopt the Western lifestyle.” Lead author Ta-Chiang Liu, an associate professor of pathology and immunology in Washington, said. University of St. Louis.

“In our study, long-term intake of a Western-style diet high in fat and sugar can promote inflammatory bowel disease and increase the risk of gut infections in the gut. It has been shown that the function of immune cells is impaired. “

Diet and damaged Paneth cells

Paneth cell dysfunction is an important feature of inflammatory bowel disease. For example, people with Crohn’s disease, a type of inflammatory bowel disease characterized by abdominal pain, diarrhea, anemia, and malaise, often fail these cells.

“Obesity itself wasn’t a problem … The problem was a high-fat, high-carbohydrate diet.”

Liu and senior author Sadeus Stappenbeck, chair of the Inflammation and Immunology Department at the Cleveland Clinic and former co-director of the University of Washington Institute and Genomic Medicine Department, will try to determine the cause of people’s Paneth cell dysfunction. I tried. They analyzed a database containing demographic and clinical data for 400 people, including an assessment of each person’s Paneth cells.

Researchers found it High body mass index (BMI) was associated with Paneth cells that appeared abnormal and unhealthy under the microscope. The higher a person’s BMI, the worse the appearance of Paneth cells. An association held for healthy adults and people with Crohn’s disease.

To better understand this relationship, researchers studied two strains of mice that are genetically predisposed to obesity. These mice chronically overeat because they have mutations that make them unable to feel full even when fed a normal diet. To the surprise of the researchers, obese mice had Paneth cells that looked normal.

In people, obesity is often the result of eating a rich diet thick And sugar. As a result, scientists fed normal mice a diet in which 40% of their calories were derived from fat or sugar, similar to a typical Western diet. Two months after this chow chow, the mice became obese and the Paneth cells appeared apparently abnormal.

“Obesity itself wasn’t a problem,” says Liu. “Eating too much a healthy diet did not affect Paneth cells. The problem was a high-fat, high-carbohydrate diet.”

Point of no return?

When the mice were returned to a healthy mouse diet for 4 weeks, the Paneth cells returned to normal. Liu says it is not yet known if people who habitually eat a Western diet can improve their gut immunity by changing their diet.

“This was a short experiment of just eight weeks,” says Liu. “For people, obesity does not occur overnight or for eight weeks … We need to do more research before we can determine if this process is reversible in people.”

Further experiments have shown that a molecule known as deoxycholic acid, secondary bile acids, is formed as a by-product of metabolism. Enterobacteriaceae, Form a link between the Western diet and Paneth cell dysfunction. Bile acids increase the activity of two immune molecules (farnesoid X receptor and type 1 interferon) that block the function of Paneth cells.

Liu et al. Are currently investigating whether fat or sugar plays a major role in Paneth cell damage. They also began researching ways to restore normal Paneth cell function and improve gut immunity by targeting bile acids or two immune molecules.

The work was funded by the National Institutes of Health, the Helmsley Charitable Trust, the University of Washington’s Genome Technology Access Center and the Core Center for Gastrointestinal Disease Research.

Source: Washington University in St. Louis