Dr. Eugene Chang provides new insights into the role of gut microbes in IBD

October 27, 2014

Eugene B. Chang, MD

Research by Eugene B. Chang, MD, the Martin Boyer Distinguished Professor of Medicine and Director of the NIDDK P30 Digestive Diseases Research Core Center, offers new insights into the role of gut microbes in inflammatory bowel disease (IBD). 

Dr. Chang’s lab has been trying to determine why many complex immune disorders such as IBD are more common today than 50-100 years ago.  This period of time is too short for any significant drift in Human genetics to account for this finding.  Rather, Dr. Chang believes that changes in diet, life style, and environment are triggering these diseases in genetically prone individuals.

In support of this, Dr. Chang’s group observed that mice susceptible to IBD develop disease at a much higher rate when fed a high saturated fat, “western” type of diet compared to diets that contain other types of unsaturated dietary fats. This study helped researchers understand the epidemiological trends of complex immune disorders, underscoring the impact of environment and diet in precipitating disease. “This knowledge can potentially be used to identify individuals at increased risk for developing IBD, by assessing their genetic susceptibility and gut microbial profiles,” Dr. Chang said. “Once we know who is at risk, there are many ways to reshape their gut microbial composition to lower the incidence of the disease or intervene in active disease.”

Dr. Chang’s lab is conducting research on humans in addition to mice—He and his colleagues were awarded one of only five NIH Human Microbiome Demonstration Projects to investigate the role of gut microbes in gastrointestinal disease and one of two focused on IBD.

“We have come to realize there is no ‘one size fits all’ regimen for treating and managing patients with this disease. We have to be smarter about how we can customize our approaches to the physiology and biology of the individual. We’re not there yet, but with advanced technologies that have emerged over the past 10 years, we are much closer to realizing the promise of what can be done,” Dr. Chang said. “We are likely to see new developments in personalized medicine over the next five to 10 years that will make a real difference in better outcomes.”

In another study, Dr. Chang is studying the gut microbes and ileal pouch mucosa of patients with ulcerative colitis who have had their colon removed.  Over 50 percent of these patients develop a condition in the ileal pouch that looks like ulcerative colitis. “We are analyzing the data now, and will soon be able to predict with greater certainty who is at risk for the disease,” Dr. Chang said. “This will help us know which patients to treat so we are not subjecting low-risk people to regimens they don’t need.”

Dr. Chang is also studying the role of gut microbes in regulating metabolism as it relates to weight gain. Regular mice fed a Western diet will get obese, yet microbe-free mice on the same diet will not gain weight. When gut microbes from the first mice are placed in the germ-free mice, the latter will gain weight, showing that the weight gain phenotype is carried with gut microbes. Dr. Chang says, “The only way we can change a person’s metabolic set point now is through bariatric surgery. If we can gain a better understanding of how gut microbes regulate our metabolism, we should be able to develop novel medical approaches to reduce weight and prevent obesity.”

Learn more about Dr. Chang