A low-fiber diet is considered to be a potential trigger for such diseases as colon cancer and irritable bowel syndrome arising from inflammatory processes or an autoimmune re-sponse. Scientists at the Institute of Diabetes Research and the Forschergruppe Diabetes e. V., examined whether, conversely, a fiber-rich diet – particularly one that has a high content of soluble fiber – could prevent the autoimmune disease type 1 diabetes. To this end, they analyzed over 17,600 food records from more than 3,300 children from Germany and the United States who took part in the TEDDY study. The records were kept at regular intervals, when the children were between nine and 48 months of age. The children’s islet autoantibody status was checked every three months. When one or multiple islet autoantibodies are detected in the blood, this is referred to as islet autoimmunity. If multiple islet autoantibodies are found, almost 100 percent of the individuals concerned will go on to develop type 1 diabetes within 20 years.
Can soluble fiber protect against islet autoimmunity?
When soluble fibers are digested in the gut, they undergo fermentation, which produces short-chain fatty acids, to which anti-inflammatory properties are ascribed. In addition, there are indications that fibers affect the composition of the intestinal flora. The micro-organisms that inhabit the bowel, meanwhile, interact with the immune system. Current studies indicate that the microbiome of individuals with type 1 diabetes differs from that of healthy individuals. The diabetes researchers from Munich therefore assumed that a high intake of soluble fiber in the first two years of life could protect against the development of islet autoimmunity. Most cases of islet autoimmunity occur at this stage in life.
Unfortunately no evidence was found to support this assumption. At no stage in early childhood could a statistically significant connection be established between the amount of high-fiber food ingested and a later onset of islet autoimmunity or an earlier manifestation of type 1 diabetes. “Our analyses lead us to conclude that an insufficient intake of fiber has no direct effect on inflammatory processes in the body that lead to type 1 diabetes,” says Dr. Andreas Beyerlein, a statistician at the Institute of Diabetes Research, summarizing the results. “We are still a long way off from making dietary recommendations for preventing type 1 diabetes in high-risk individuals,” adds Dr. Beyerlein’s colleague, Dr. Sandra Hummel, who is a nutritional scientist. “It may be that other food components influence the microbiome and the development of autoimmunity.” Given the still relatively short follow-up time for participants in the TEDDY study (median follow-up = five years) long-term effects cannot, however, be ruled out.
The TEDDY Study is funded by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institute of Allergy and Infectious Diseases (NIAID), National Institute of Child Health and Human Development (NICHD), National Institute of Environmental Health Sciences (NIEHS), Juvenile Diabetes Research Foundation (JDRF), and Centers for Disease Control and Prevention (CDC).
Andreas Beyerlein, Xiang Liu, Ulla M Uusitalo, Minna Harsunen, Jill M Norris, Kristina Foterek, Suvi M Virtanen, Marian J Rewers, Jin-Xiong She, Olli Simell, Åke Lernmark, William Hagopian, Beena Akolkar, Anette-G Ziegler, Jeffrey P Krischer, Sandra Hummel, and the TEDDY study group. Dietary intake of soluble fiber and risk of islet autoimmunity by 5 y of age: results from the TEDDY study Am J Clin Nutr ajcn108159; First published online July 8, 2015. doi:10.3945/ajcn.115.108159