Inflammatory bowel disease (IBD) is a group of disorders that cause painful and chronic inflammation to the digestive tract with Crohn’s disease and ulcerative colitis being the most common forms. It is a disease that cannot yet be cured, but it can be managed with the use of medications or in some cases by surgery. Diet and lifestyle can help play a role in managing symptoms of IBD and in this podcast, I’ll look at some of the evolving research for future potential treatments.
Inflammatory bowel disease is a chronic inflammatory condition of the colon and rectum. Ulcerative colitis and Crohn’s disease are the two main types of IBD. Ulcerative colitis affects the colon whereas Crohn’s disease can occur in any part of the intestines. Common symptoms of IBD include persistent diarrhoea, abdominal pain, rectal bleeding and bloody stools, weight loss and fatigue.
The exact cause of IBD is unknown but is likely the result of a defective immune system where the immune system responds incorrectly to environmental triggers such as viruses, bacteria or even food in the gut. The result is inflammation of the gastrointestinal tract.
IBD should not be confused with irritable bowel syndrome or IBS. Although people with IBD may experience some similar symptoms to IBS, IBD and IBS are very different conditions.
No specific diet has been shown to prevent or treat IBD. Most people with Crohn’s disease or ulcerative colitis can tolerate all types of food and don’t require any special dietary restrictions outside of restricting known trigger foods. For example, during flare-ups of the disease, some people find that a bland, low-fibre diet is easier to tolerate than one that contains high-fibre or spicy foods.
Many people with IBD are likely to follow dietary advice from a variety of sources, including the Internet, and even though there is no shortage of dietary advice and a range of diets to try, there is very little scientific evidence for most approaches. So for this podcast, I wanted to touch on two particular areas of interest.
Even though IBD and IBS are very different conditions, IBD does have some connection to IBS because IBS-like symptoms are over-represented in people with IBD. Considering the growing evidence of the beneficial role of a low-FODMAP diet to treat IBS, a low-FODMAP diet is at least being looked at for what role it could play in IBD.
FODMAP is an acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols and include carbohydrates such as lactose, fructose, fructans (which are long chains of fructose molecules like inulin) and sugar alcohols. FODMAPs are found in many foods including wheat, milk, pears, plums, onions, garlic and legumes.
FODMAPs can be poorly absorbed in some people, leading to their accumulation in the small intestine and passing into the large intestine. Once there, they can draw more water into the bowel which increases the chance of diarrhoea. FODMAPs can also increase gas production from their fermentation by colonic bacteria. These effects of FODMAPs in the bowel explain many of the symptoms reported in IBS.
We are now starting to see some clinical trials emerging in this area asking the question if a low-FODMAP could offer some therapeutic benefit in people with IBD, Italian researchers in 2019 completed a small short-term study. Fifty-five adults aged between 20 and 75 years with IBD who were in remission or had mild disease activity took part in the trial. Each person was randomly allocated to follow either a low-FODMAP diet or a standard diet for 6 weeks. Various measures such as disease severity, inflammation and quality of life were assessed. And I’ll link to the study in the show notes. https://pubmed.ncbi.nlm.nih.gov/31470260
The results looked promising with those on the low-FODMAP diet experiencing a decrease in disease severity and inflammation and this was seen in people with Crohn’s disease and ulcerative colitis. There was also a small improvement in the quality of life in those on the low-FODMAP diet. This small proof-of-concept pilot study shows promise that a low-FODMAP diet may have some therapeutic potential in managing IBD. A low-FODMAP diet though should be undertaken with advice and support from a dietitian and is not recommended to be a long-term diet solution.
And following on from this research study, a similar type of trial published in 2020 in people with IBD found some improvement in IBS-like symptoms and health-related quality of life. And taking it one step further, a stool analysis found lower levels of bacteria believed to regulate the immune response in people on the low-FODMAP diet. And I’ll link to this study in the show notes. https://pubmed.ncbi.nlm.nih.gov/31586453
And that last point I made about gut bacteria is now starting to resurface in some very interesting ways. And it is to do with the highly experimental therapy of faecal microbial transplants or FMT for short. It is the literal transplant of an entire microbial ecosystem from the stool of a healthy donor to the recipient via a colonoscopy to help restore or restructure the gut microbiota.
In a study from 2015, it was found that a significantly greater percentage of people with active ulcerative colitis who were treated by FMT experienced remission, compared with those who were given a placebo. Compare that to a study from just last year that examined treating patients with Crohn’s disease who were in remission with FMT and also found a lower rate of flare-ups of the disease.
So, it is still early days for this sort of therapy before it moves from clinical trials to mainstream treatment, but it builds on what we know about our gut and the microbes in it for how they affect our immune system. If you want to read a recent update review on this field of FMT therapy in IBD, I’ll link to a paper in the show notes. https://www.frontiersin.org/articles/10.3389/fphar.2020.574533/full
So, let’s wrap this up. Although none of the studies published to date suggests that dietary therapy should completely replace traditional therapy with medications or surgery for IBD, in certain people, diet could be attempted as a first-line therapy with close follow-up and change of therapy if a complete response is not achieved. In other people, dietary modification can be used to potentially augment the effectiveness of medications and to help with the relief of the painful symptoms of IBD.
So that’s it for today’s show. You can find the show notes either in the app you’re listening to this podcast on if it supports it, or else head over to my webpage www.thinkingnutrition.com.au and click on the podcast section to find this episode to read the show notes.
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I’m Tim Crowe and you’ve been listening to Thinking Nutrition.