In October 2019 researchers from Taiwan published their review of nutrition and diet in inflammatory bowel disease. The researchers stated that the incidence of inflammatory bowel disease has been increasing for decades, with studies showing that the incidence is higher in more westernized countries. Research has shown that some substances produced following the digestion of food actually decreases the diversity of the gut microbiota and causes a microbial imbalance of the microbiome. It is then that chronic inflammation occurs in some genetically susceptible individuals and inflammatory bowel disease develops. As a result of this finding, further studies have been undertaken to assess the potential therapeutic effects of nutrients and dietary interventions on the course and pathological processes of inflammatory bowel disease. Carbohydrates, fats, proteins and fibre are being researched and their roles in the inflammatory process are gradually being discovered. Undigested carbohydrates have been shown to cause overgrowth of gut bacteria with inflammation occurring by an alteration in the gut microbiome. In addition, omega-3 polyunsaturated fatty acids have been shown to have less pro-inflammatory properties than omega-6 polyunsaturated fatty acids. It has also been noted that high fibre foods produce more short-chain fatty acids in the gut which helps to improve the diversity of gut microbiota. Moreover, some dietary interventions have been designed and studied with promising results. A low FODMAP diet (a diet low in fermentable carbohydrates FODMAP = fermentable oligosaccharides, disaccharides, monosaccharides and polyols) has been recommended for inflammatory bowel disease and it has also been suggested for individuals with inflammatory bowel disease-like symptoms. A gluten-free diet was designed for individuals with coeliac disease which has been shown to be effective in decreasing inflammation and to induce remission by decreasing non-digested carbohydrates in the gut. The Paleolithic and semi-vegetarian diets have also been assessed and it is felt that these may also be beneficial in some settings. However, it should be noted that although the results are promising, there is no high quality evidence to currently support their use. Further research is therefore required which should be focused on the decrease of inflammation and healing instead of relief of the symptoms.
Hsieh MS et al. Nutritional and dietary strategy in the clinical care of inflammatory bowel disease. J Formos Med Assoc. 2019 Oct 14. pii: S0929-6646(19)30468-1.