Prebiotics are substances found in food or supplements that support the growth of probiotics in your digestive system, according to the academic book Dietary Interventions in Gastrointestinal Diseases. While they may not get as much attention as the organisms they support, prebiotics play a crucial role in developing and maintaining a diverse and balanced population of gut bacteria, which may be especially important for people with ulcerative colitis. According to a review published in the Journal of Biomedical Science, prebiotics are mostly varieties of dietary fiber, which the body’s own digestive juices and enzymes can’t effectively break down — leaving bacteria in the colon to do the job instead. “Think of your gut as a garden,” says William R. DePaolo, PhD, the director of the center for microbiome sciences and therapeutics at the University of Washington School of Medicine in Seattle. “If you want to colonize and grow something, you plant seeds. Those seeds would be the probiotics.” Prebiotics, in contrast, “are the fertilizer you put on that garden,” says Dr. DePaolo. They help healthy bacteria grow and thrive and maintain a stable population in your gut. While the role of gut bacteria in UC isn’t fully understood, it’s clear that people with inflammatory bowel disease (IBD) tend to have a different profile of bacteria in their intestines, and certain differences and changes in the composition of gut bacteria can help predict the course of the disease. In a review published in the Journal of Experimental Medicine, researchers found that different strains of gut bacteria may combat different chronic inflammatory conditions like UC.
How Prebiotics Can Help
According to DePaolo, people with an IBD like ulcerative colitis are more likely to have an out-of-balance microbiome, a condition known as dysbiosis. This may contribute to disease activity in UC because of the deficiency of compounds produced by healthy bacteria, called short-chain fatty acids (SCFAs). “Short-chain fatty acids are one of the major molecules that regulate inflammation,” says DePaolo, both within the gut and in the body at large. They do this by enhancing the effects of a type of immune system cell — known as a regulatory T cell — that helps regulate other pro-inflammatory T cells. If you have fewer SCFAs in your body, “you’re going to have less regulation,” says DePaolo, “and that’s going to allow inflammation to be worse.” By helping healthy bacteria grow, prebiotics can help increase SCFAs and reduce inflammation. While many differences in gut bacteria in people with UC have been found in scientific studies, it’s less clear what effect prebiotics have on these differences, or on disease outcomes. In a review of the benefits of prebiotics published in June 2021 in the Journal of Clinical Medicine, researchers examined previous studies on how different prebiotics in people affects inflammatory bowel diseases like UC. Although some studies showed that certain forms of prebiotics were beneficial to UC patients, there was wide variation in results. Therefore, the researchers concluded that the use of prebiotics to relieve or eliminate symptoms of UC is not recommended. This echoes a review of studies published in February 2016 in the journal Best Practice and Research Clinical Gastroenterology that emphasized the difficulty in drawing conclusions from studies involving probiotics and prebiotics in people with UC. While some results have been promising, the researchers wrote, most studies have been small, and they often have large differences in their design. For instance, many of the studies in the Journal of Clinical Medicine Review were performed on different animals. Additionally, many studies evaluate a combination of probiotics and prebiotics — known as synbiotics — making it unclear what effect prebiotics by themselves would have had. While the research may be inconclusive on any additional benefits regarding UC, prebiotics are naturally tied to healthy and nutritious food options, and may still affect gut health.
7 Categories of Good Sources of Prebiotics
According to a review published in March 2018 in the journal Current Developments in Nutrition, there are seven categories of prebiotic dietary fibers that support digestive health. These categories include: Most Americans consume about 50 percent less fiber than is recommended, so DePaolo recommends including as many fiber-rich foods in your diet as possible, as long as you tolerate them well. “Getting [prebiotics] from different sources is good, because there are different types of fiber,” says DePaolo. “Variation really covers all your bases.” However, it’s important to talk to your doctor or dietitian before trying out any new food for symptom relief from an IBD. A food diary might also be helpful in determining foods that are beneficial. Additional reporting by Zachary Smith.
