New, "designer" dietary fiber may eliminate side effects of current IBS treatment

A newly-developed, "designer" dietary fiber with an added potential prebiotic effect may eliminate the side effects of current treatment for Irritable Bowel Syndrome (IBS) which affects 10-20 percent of the population, disproportionately women.

The collaboration between a gastroenterologist at Rush and a carbohydrate chemist at Purdue University led to the development of the new product, a natural starch derived from a mixture of seaweed and starch in which the release of starch fiber in the gastrointestinal tract can be delayed, slowed and controlled to occur in the colon, rather than in the stomach and upper intestine.

"This new product prevents the discomfort and bloating associated with current fiber therapies, while getting our new fiber into the colon and specifically distal colon where traditional fiber products typically do not reach and where many diseases of colon-like cancers develop," said Dr. Ece Mutlu, principal investigator the phase II trial that will begin at Rush in January 2014. "This can provide an effective treatment for IBS, decrease the risk of colon cancer and possibly inflammatory diseases like colitis," she added. The study seeks 200 people who have been diagnosed with IBS and constipation.

In an earlier Phase I study with 60 patients suffering from constipation, the newly designed fiber was shown to be safe, better tolerated and with fewer side effects than currently available fiber treatments for constipation, and it had a positive effect on intestinal microbiota composition by promoting the growth of "healthy" bacteria in the colon.

"We wanted to create a fiber with a slow rate of fermentation to avoid rapid expansion of the gut and thus decrease the likelihood of common side effects of conventionally used fibers like bloating," said Dr. Ali Keshavarzian, professor and director of gastroenterology at Rush.

The fiber is also designed to produce a high level of a short chain fatty acid, butyrate in order to promote gut health and to have a so-called "prebiotic effect" for it to be a supplemental treatment for IBS. IBS is the most common reason for a gastroenterologist specialist consultation. Currently, there are no universally effective treatment options for IBS.

The fiber is a targeted, controlled-release fiber that travels through the large intestine to be fermented by bacteria in the entire colon including the descending [distal] colon where colon cancer, diverticulitis, ulcerative colitis and irritability commonly occur. The fiber can be designed to target different locations. This enables the bacteria in the large intestine to receive important nutrients from the fiber, which promotes overall gut health.

"We worked closely with Purdue University food scientist Bruce Hamaker, PhD, to develop well-tolerated fiber with targeted delivery to the entire colon that could promote "gut health" and possibly prevent and treat colonic diseases where changes in the gut play a key role," said Keshavarzian.

A $2.5 million federal grant to develop the fiber invented at Rush University Medical Center and Purdue University's College of Agriculture was given to Nutrabiotix LLC, based in the Purdue Research Park, which is commercializing the patented designer fiber created by Hamaker, and Keshavarzian.

The two-year SBIR Phase II grant of $2.5 million is from the National Institute of Diabetes and Digestive and Kidney Diseases, which is part of the National Institutes of Health (NIH) and the U.S. Department of Health and Human Services. This two-year clinical trial will begin in January 2014 and will be completed in 2016. Hamaker is director of the Roy L. Whistler Center of Carbohydrate Research and holds the Roy L. Whistler Chair in Carbohydrate Science in Purdue's Department of Food Science.

Nutrabiotix had received an SBIR Phase I grant from the NIH worth $250,000 in 2010. The State of Indiana's 21st Century Fund matched that funding with $100,000 the same year.