Inflammatory bowel disease: High

More than 6 million people around the world have inflammatory bowel disease (IBD) — an umbrella term for Crohn's disease and ulcerative colitis, which both cause inflammation of the gut.

A person's diet plays an important role in increasing the risk for and alleviating symptoms of IBD. Previous research links a high-sugar diet to a greater risk of developing inflammatory bowel disease.

A high-sugar diet is a known cause of inflammation throughout the body. Increased sugar intake has also been linked to other diseases including obesity, chronic kidney disease, and cardiovascular disease.

Now, researchers from the University of Pittsburgh found that consuming a high-sugar diet could also worsen symptoms for people with IBD, via a mouse model.

This study was recently published in the journal Cellular and Molecular Gastroenterology and Hepatology.

Inflammatory bowel disease occurs when the body's immune system attacks your bowels, causing inflammation, pain, and swelling in the intestines.

Although researchers are still not sure exactly what causes IBD, there are some known risk factors, including:

Symptoms of IBD include:

Currently, there is no cure for IBD. Treatment centers around reducing a person's symptoms and avoiding any complications. Common treatments for IBD include:

When asked why he decided to study the effect of sugar on IBD, Tim Hand, PhD, associate professor of Pediatrics and Immunology at UPMC Children's Hospital of Pittsburgh at the University of Pittsburgh and senior author of the study, told Medical News Today:

"Sugar is pervasive in the diet of high-income countries with the average person consuming up to a kilogram a week. This amount of sugar is unprecedented for our species and thus how high levels of sugar consumption might affect the intestine's response to damage seemed like a timely and important question to answer."

For the study, Dr. Hand and his team used a mouse model to test the effect either a standard or high-sugar diet had on IBD.

Mice were fed either a standard or high-sugar diet and then treated with a chemical to mimic IBD colon damage after they were fed one of the two diets.

Scientists reported that during the study, all mice fed a high-sugar diet died within nine days of the 14-day experiment. All the mice fed a standard diet survived for all 14 days.

At the conclusion of the experiment, researchers examined the colons of the mice who had died after eating a high-sugar diet and found it inhibited the healing or regeneration process of the intestine.

"The intestine is covered in an epithelial layer, like the skin, but with a layer of mucus on its surface," Dr. Hand explained. "This intestinal barrier needs to regenerate itself every three to five days and does so via the action of ‘stem cells’ that divide to make new copies of themselves constantly."

"As you can imagine, these stem cells are very important in regenerating damaged epithelium and must divide even faster to replace dead and damaged cells. What we found was that high sugar concentrations directly affected the ability of stem cells in the intestine to regenerate in response to damage. Under high sugar conditions, when they need to increase their function, intestinal stem cells were unable to do so."

– Tim Hand, PhD, senior study author

Dr. Hand said the study findings suggest that people with IBD might want to avoid sugary soft drinks and candy where a large amount of sugar can be consumed very quickly.

He added that it's also important to discuss any dietary changes with your doctor first.

As for the next steps in this research, Dr. Hand said they are working closely with their collaborator Dr. Semir Beyaz at the Cold Spring Harbor Laboratories in New York to try to define how diet, the immune response, and the microbiota combine to shape the function of the intestine.

"In addition to high sugar and high fat diets, as are common in high-income countries, we are also working on how malnutrition — low protein [and low] fat diets — contribute to intestinal disease in children in low-income countries," he added.

MNT also spoke with Dr. Rudolph Bedford, a gastroenterologist at Providence Saint John's Health Center in Santa Monica, CA, about this study.

He said the study findings were very provocative and likely to be true.

"In Western societies, we are seeing an increasing rate of IBD and we certainly do have high-sugar diets," Dr. Bedford continued. "Sugar itself has really an effect on the gut microbiome and certainly may put patients at risk for IBD. And those with IBD in terms of healing of their bowels will certainly (also) be compromised. My suspicion is that patients in the future — and even now — will be told that their diets should be very low in sugar in order to prevent IBD, and also (for) those who do have IBD to aid in the healing."

– Dr. Rudolph Bedford, gastroenterologist

For those looking to lower their sugar intake, Dr. Bedford says eating a diet high in fiber and very low in processed foods is key."(And) drinking plenty of water (and) staying away from all of these sugary drinks," he added.