The RunDown of the Low FODMAP Diet

With the recent surge in food sensitivities in the population, more focus has been drawn to elimination diets and their short and long term impact on our health. One of the most common is the low FODMAP diet with its restriction of fermentable Oligosaccharide, Disaccharide, Monosaccharide and Polysaccharide foods. These foods have a specific class of carbohydrates that can ferment in your gut and cause bloating, gas, and inflammation. The foods to avoid in this diet include:

• High lactose dairy (milk, ice cream, yoghurt)
• Processed sugar
• Fibrous veggies (broccoli, cauliflower, kale)
• Onions
• Garlic
• Asparagus
• Legumes (beans, lentils, chickpeas)
• Fruits high in fructose (mango, pear, watermelon)
• Cereals (wheat, rye)

The low FODMAP diet is a great short term diet (typically 4-8 weeks) that helps identify any fermentable carbohydrate foods that may be causing digestive distress. It typically takes place in 3 stages:

1. Reduction or elimination of high FODMAP foods
2. Slow, careful reintroduction of each food
3. Identification of the foods that cause IBS symptoms

With a (hopefully) shorter list of FODMAP foods to now avoid or carefully limit, once can enjoy all the other foods without worrying about them interfering with life. A good nutritionist or healthcare practitioner will help to personalize a long term diet plan so that nutritional needs are being met while avoiding the newly identified problem foods.

Impact on Your Gut Long Term

While this diet has been shown to help people with IBS manage their symptoms, it can be difficult to maintain long term. Not only does it impose challenging limitations on individuals who are trying to adhere to the diet, it can lead to nutritional deficiencies long term. Regular diets that include food on the FODMAP list have many health benefits, especially for the gut. Legumes, for example, are examples of high fiber foods which are essential for maintaining healthy populations of good bacteria in our guts.

The cruciferous veggies that are listed as foods to avoid, are crucial for maintaining healthy levels of Faecalibacterium, bacteria responsible for maintaining a healthy gut and supporting the immune system. Inulin and chicory root, common prebiotic supplements that help to boost a host of probiotic organisms, from the immune-supporting Bifidobacteria, to the common yet essential Lactobacillus species. With the restriction on garlic, onions, and certain fruit that contain the prebiotic FOS (fructo-oligosaccharides), one risks a decline in levels of the energy-producing probiotic species Akkermansia muciniphila.

What Can Be Done Instead

Using the FODMAP exclusion diet to identify foods that may make IBS symptoms worse is perfectly fine. Avoiding them long-term can be problematic. There is also a good chance that if there is an intolerance to a specific food found in the FODMAP chart, then it could be because the bacteria that digests it is too low. A classic example of this is Faecalibacterium. Individuals who have lower than healthy levels often get gas and bloating when eating broccoli, cauliflower, cabbage, or kale. If this is the case, then replenishing the gut with the right bacteria, rather than avoiding that food entirely, might be the right path to take.

Possibly the best way to do that is to test and replace. How does one do that? It's quite simple. Take a very thorough microbiome test (preferably one that uses whole genome DNA sequencing) in order to see what beneficial bacteria and probiotic species might be lacking, then either order custom made probiotics based off of that test, or very carefully reintroduce food for these bacteria back into the diet. That's why it's so important to talk to your gastroenterologist or nutritionist and take a comprehensive microbiome analysis test before swearing off watermelon and mango forever.