Microbiome-targeted diet may improve symptoms in IBD patients

Last Updated: 2020-01-24

By Megan Brooks

NEW YORK (Reuters Health) - A diet targeting the microbiome of patients with inflammatory bowel disease (IBD) can improve gut health and reduce symptoms, results of a small study suggest.

IBD patients have an imbalance of gut bacteria, which contributes to inflammation. Researchers at the University of Massachusetts (UMASS) Medical School "rationally designed" the IBD anti-inflammatory diet (IBD-AID) to "modulate inflammation by favoring bacteria able to produce short-chain fatty acids while providing a nutritious and balanced diet," Dr. Ana Maldonado-Contreas told Reuters Health by email.

She explained that foods in the IBD-AID are staged, and texturally modified according to the patients' symptomatology. The diet is organized around four key components. It includes a variety of probiotic foods to promote the establishment of commensal bacteria, prebiotic foods to nourish commensal bacteria, balanced nutrients to meet dietary requirements, and substitution of adverse foods thought to foster pathogenic microbiota.

The researchers enrolled 21 IBD patients in a study that included four to six weeks of baseline and 10 to 12 weeks of dietary intervention with the IBD-AID.

In both periods, patients were asked to collect biweekly stool samples to assess the composition of the microbiome; report what they ate three times per week to determine adherence to the IBD-AID; and report changes in medications, symptoms and quality of life through validated questionnaires.

"We collected over 400 dietary recalls and over 300 fecal samples from the 19 patients completing the study. Participants reported an average 76% adherence to the IBD-AID, which is fantastic! Research has shown that more than 40% of patients fail to adhere to dietary recommendations," Dr. Maldonado-Contreas told Reuters Health.

The majority (61.3%) of patients treated for at least eight weeks, who achieved as minimum a 50% dietary compliance, reported a significant decrease in disease severity. Fecal samples showed that the IBD-AID significantly promoted microbiota signatures that have been associated with colonic health.

Dr. Maldonado-Contreas said the next step is to confirm their findings in a larger group of patients. "Completion of a larger trial will help us to build strong evidence-based dietary guidelines for patients struggling with IBD. We are currently seeking funding to complete a large prospective controlled study using the IBD-AID," she said.

Dr. Maldonado-Contreas reported her findings this week in Austin, Texas, at the Crohn's and Colitis Congress, sponsored by the Crohn's and Colitis Foundation and the American Gastroenterological Association (AGA).

Dr. David Rubin, chair of the organizing committee for the conference, said there has been "an explosion of interest and work in the microbiome driven in part by the NIH's investment in the Human Microbiome Project (http://bit.ly/2Rmezjk) but also just in the evolution of technologies to measure the microbiome and actually do any kind of meaningful research."

"The fast way to change your microbiome is through diet. And if we believe that the microbiome is either a cause or an effect related to IBD pathogenesis than modifying it in theory should be a way to address the inflammation and provide treatment or at least prevent recurrence," Dr. Rubin, professor of medicine at University of Chicago, told Reuters Health by phone.

He noted that research groups have been trying to define a diet that is less inflammatory or, in this case, anti-inflammatory, as a way to manage the disease. "This new study is interesting and a step in the right direction," said Dr. Rubin, but "we are far from having a diet that specifically treats IBD and we are even further from knowing if the microbiome is actually causing or driving IBD."

It's also becoming clear, said Dr. Rubin, that an individual's genetic make-up determines how they respond to certain foods.

"Therefore, the ultimate determinant of what the right diet might be isn't going to be a one-size-fits-all diet for everybody. It's going to be a diet that is personalized based on its functional effect on you and the way we will measure that will be in the byproducts of what happens in your gut. And it won't always be in stool. We are looking at ways to do metabolomic analyses with urine or even breath to know whether or not the diet you're eating is working well with the bacteria in a positive way," he explained.

The study had no commercial funding and the authors have no relevant conflicts of interest.

SOURCE: http://bit.ly/2NRtYpP Crohn's & Colitis Congress, presented January 23, 2020.