Study: Western-Style Diet Promotes Inflammation That Leads to Chronic Diseases

Jill Murphy, Associate Editor

Processed diets may initially reduce the incidence of foodborne infectious diseases, such as E.coli, but might also increase the incidence of diseases characterized by low-grade chronic infection and inflammation.

Processed diets may initially reduce the incidence of foodborne infectious diseases, such as E.coli, but might also increase the incidence of diseases characterized by low-grade chronic infection and inflammation, such as diabetes, according to researchers in the Institute for Biomedical Sciences at Georgia State University.

This study used mice to investigate how changing from a grain-based diet to a highly processed, high-fat Western-style diet impacts infection with the pathogen Citrobacter rodentium, which resembles E.coli infections in humans.

Gut microbiota provide a number of benefits, such as protecting a host from infection by bacterial pathogens, and can be influenced by a variety of factors, but specifically diet. The Western-style diet lacks fiber and contains high amounts of processed foods, red meat, high-fat dairy products, high-sugar foods, and pre-packaged foods. This lack of fiber is believed to have contributed to increased prevalence of chronic inflammatory diseases, such as inflammatory bowel disease, metabolic syndrome, and cancer, according to the study.

In the current study, the researchers found switching mice from a standard grain-based rodent chow to a high-fat, low-fiber Western-style diet resulted in a rapid reduction in the number of gut bacteria. Mice fed the Western-style diet were frequently unable to clear the pathogen Citrobacter rodentium from the colon and were prone to developing chronic infection when re-challenged by this pathogen.

“We observed that feeding mice a Western-style diet, rather than standard rodent grain-based chow, altered the dynamics of Citrobacter infection, reducing initial colonization and inflammation, which was surprising. However, mice consuming the Western-style diet frequently developed persistent infection that was associated with low-grade inflammation and insulin resistance,” said senior co-author of the study Andrew Gewirtz, MD, professor in the Institute for Biomedical Sciences in the press release. “These studies demonstrate potential of altering microbiota and their metabolites by diet to impact the course and consequence of infection following exposure to a gut pathogen.”

The researchers concluded the Western-style diet reduces the numbers of gut bacteria and promotes encroachment of microbiota into the intestine, potentially influencing immune system readiness and the body’s defense against pathogenic bacteria, according to the study.

“We speculate that reshaping gut microbiota by nutrients that promote beneficial bacteria that out-compete pathogens may be a means of broadly promoting health,” said senior co-author of the study Jun Zou, MD, assistant professor in the Institute for Biomedical Sciences at Georgia State, in the press release.

REFERENCE

Processed Diets Might Promote Chronic Infections That Can Lead to Disorders Such as Diabetes, Researchers Find. Georgia State University. Published April 28, 2021. Accessed April 29, 2021. https://news.gsu.edu/2021/04/28/processed-diets-might-promote-chronic-infections-that-can-lead-to-disorders-such-as-diabetes-biomedical-sciences-researchers-find/