By Dr Malcolm Mackay

Bloating, crampy pains and irregular bowel function are common symptoms and may lead to the diagnosis of irritable bowel syndrome or SIBO. It is important to exclude underlying medical conditions such as coeliac disease. Sufferers often attribute these symptoms to food allergies or parasites, but these are seldom the cause. Intolerance to salicylates, amines and glutamate are uncommon and are not discussed in this document.

We live in a symbiotic relationship with the microbes in our colon – the gut microbiome – and the health of the gut depends on the health of the microbiome. As individuals and as a community we have a depleted diversity of gut microbes due to good hygiene, antibiotics and lifelong exposure to animal products and fibre depleted refined grains and vegetable oils. Many of us will have a gut microbiome that is nearing a tipping point to a persistent state of dysbiosis – an unhealthy balance of microbes that does not support gut health. A severe bout of gastroenteritis or another course of antibiotics may be all it takes to tip someone over into long term gut problems.

Gut symptoms, such as pain and bloating, often lead to a downward spiral of food restriction and progressively more intolerance to fermentable carbohydrates. The low fibre, low FODMAP diet may relieve symptoms in the short term, but it starves the microbes that protect the gut barrier and support gut health by producing short chain fatty acids and other postbiotics. Long term gut symptoms ensue. The low FODMAP diet was never intended as a long-term strategy. The greater the degree and duration of restriction, the more difficult it becomes to reverse the dysbiosis and food intolerances.

The solution to gut dysbiosis and FODMAP intolerance is a reverse elimination diet. The first step is to eliminate foods that damage the gut or promote the growth of inflammatory microbes. These foods are replaced with increased quantities of low FODMAP starchy foods. Some individuals may need to use mindfulness techniques to reduce hypervigilance to visceral sensations. The next step is to reintroduce FODMAPs and other problem foods, in a graduated fashion over several months. If a particular food always brings back symptoms, then perhaps back off that item and work on others instead. Legumes are worth persevering with, even if that means starting with a teaspoon per day and freezing the remainder for subsequent days. Low stress days with no important events may be times to up the ante on reintroducing foods, while busy days with stressful events may be times to take a step backwards.

Stage one – eliminate non-health supporting food and additives

• All dairy foods from all species
• Meat, chicken, fish, eggs
• Vegetable oil
• Emulsifiers from processed foods
• Salt (including soy sauce and other high salt condiments)

Stage two – transition to a starch-based diet

(This is not a strict elimination diet – see our information on elimination diets)

• Potatoes, limited quantities of sweet potatoes
• Brown rice, millet, buckwheat (whole grains or pasta well cooked)
  •  Hold off on quinoa, bread and other yeast products
• Cooked rolled oats unless poorly tolerated
• Tofu may be used in small quantities
• Cooked vegetables (Lettuce may be eaten raw)
• Low FODMAP fruits including bananas
• Limit nuts and seeds to 1 tablespoon/ 10g per day

Stage three – reverse elimination

• Reintroduce whole wheat products – pasta, Freekah, Cous cous, homemade flour products
  • Bread may be problematic due to salt and other ingredients
• Onion and other allium group foods
• High fructose foods may be tolerated when consumed with ‘starches’
• Legumes, well cooked and drained
  • Lentils are often best tolerated
  • Experiment with other beans
• Sprouting grains and legumes may increase tolerability

Stage four – maintenance and further diversity

• Continue increasing legumes and other FODMAP foods as tolerated
• Periodically re-challenge with “problematic foods” such as onion and garlic

Key points:

• Stop all dairy foods.
• Minimise or eliminate other animal products
• Avoid emulsifiers and maltodextrins in processed food
• Add in more starchy foods – oats, brown rice, whole grain pasta, potatoes, and sweet potatoes
• Keep fat content low – limit nuts, seeds, and avocados. No oil!
• Limit salt
• Slowly increase beans and other high FODMAP foods
• Drink plenty of water
• Increase physical activity and reduce sedentary behaviour

See also:

• Elimination diets
• FODMAPS

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Page created 28 June 2020
Page last updated 28 June 2020

• Resources

FODMAPs is an acronym for Fermentable Oligo-saccharides, Di-saccharides, Mono-saccharides And Polyols.

FODMAPs are a group of sugars and short chain carbohydrates that are not absorbed in the small intestine (like dietary fibre and resistant starch). Bacteria in the large intestine (or even in the small intestine) ferment FODMAPs to produce large amounts of gas (hydrogen and methane), which can be very uncomfortable, particularly to those with irritable bowel syndrome. They can also act as a laxative by preventing excess water from being absorbed by the intestine

Irritable Bowel Syndrome is a common gastro-intestinal disorder characterized by abdominal bloating, excess gas, crampy pain and diarrhoea and/or constipation. Diagnosis is made on the basis of long-term symptoms and the exclusion of other causes such as inflammatory bowel disease (Crohn’s disease and Ulcerative colitis), Coeliac disease (caused by gluten in wheat and related grains) and other diseases. If you have Irritable Bowel Syndrome, a whole foods plant based diet will provide the high fibre diet that is recommended, but you may need to limit the quantities of some foods. As your gut health improves on a whole foods plant based diet you may find that you are better able to tolerate high FODMAP foods.

FODMAPs are comprised of several groups:

1. Fructose
2. Lactose
3. Sugar polyols – sorbitol and mannitol
4. Fructans and GOS (galacto-oligosaccharides).

Fructose and lactose are only a problem to individuals who lack the capacity to absorb them from the small intestine. Most non-European adults cannot absorb lactose but this is not an issue on a plant-based diet because lactose is only found in dairy products, not plants. There seems to be an epidemic of fructose intolerance. We suspect that this is related to the gut inflammation and gut bacteria imbalance that we discussed on the Gut Health page. Fructose absorption is assisted by glucose so it is really the excess fructose relative to glucose that causes problems. (Cane sugar is a di-saccharide of fructose and glucose so it’s not a FODMAP, just a concentrated carbohydrate devoid of any other nutrients). For more troublesome symptoms, you may consider taking a hydrogen breath test for fructose intolerance. Your doctor can request this test. The result may then guide you as to whether you may benefit by limiting high fructose foods, or conversely avoid unnecessary restriction of otherwise healthy fruits and vegetables.

The low FODMAP diet is not a total exclusion diet. It’s not like peanut allergy or gluten intolerance. Bacterial fermentation of undigested carbohydrate is part of the normal function of the human gut, and it only becomes a problem when there is too much gas produced too quickly, or that your gut is abnormally sensitive to distension. You can reduce the FODMAP content of your diet without compromising nutrient intake and variety simply by using smaller quantities of high FODMAP fruits and vegetables and increasing the quantities of low FODMAP ingredients. You may find that some classes of FODMAPs cause you more problems than other types. It is also probable that you will not get the same reaction on each occasion that you consume the same food items. There may be some days when you might consider a stricter low FODMAP diet such as before an important event or at times of greater stress.

Intolerance to bread and other foods containing wheat is common. This can be from the FODMAPs in whole wheat, allergy to yeast or wheat proteins, or coeliac disease. Coeliac disease is caused by an immune reaction to some of the proteins in the gluten and results in the gut lining becoming seriously damaged. Symptoms include pain, diarrhea, and malnutrition.  Gluten is present in wheat, barley and rye. Most individuals with coeliac disease can tolerate oats. Your doctor can order a blood test as an initial test for coeliac disease (NB It is important you are tested whilst still consuming gluten). Coeliac disease seems to becoming more common which may in part reflect greater community awareness and increased testing. We speculate that dietary factors may be responsible for some of the increase (see Gut Health page). Wheat products can be replaced with brown rice, oats, potatoes, sweet potatoes, brown rice pasta, buckwheat pasta, quinoa and other high fibre gluten free products.

The reputation of beans for increasing flatulence and gastrointestinal discomfort is overstated. One study of perceived flatulence found that most subjects reported no change when eating half a cup beans per day. But if this food group seems to cause you problems then there are low FODMAP options such as tofu and cooking methods that leach much of the FODMAPs out of the beans.

For more information on which foods to include in a low FODMAP diet see The Monash University Low FODMAP diet – Examples of low and high FODMAP foods. There is also an iPhone App which gives you a filter option for selecting which particular FODMAP classes you wish to restrict. This could be a very useful tool to use while shopping. Download from the App store, or see Monash University – The Low FODMAP diet page. See also our Elimination diets page.

Related pages:

• • Elimination diets
  • Gut Health
  • Gut Microbiome
  • Resistant starch
  • Energy Pie
  • Humans are herbivores
  • Low carb diets

Resources

• Monash University – The Low FODMAP Diet
• New research: Fermentable short chain carbohydrate (FODMAP) content of common plant-based foods and processed foods suitable for vegetarian- and vegan-based eating patterns (PART 1) – By Dr. CK Yao, Monash University
• New research: Fermentable short chain carbohydrate (FODMAP) content of common plant-based foods and processed foods suitable for vegetarian- and vegan-based eating patterns (PART 2) – By Dr. CK Yao, Monash University
• Food Intolerances in Gastroenterology: FODMAPs, Gluten and Beyond. Report from Gastrodiet 2015, an International Meeting on Food, Diet and Gastrointestinal Health, held 1‐3 November 2015 at Monash University, Prato, Italy.
• See also Gut Health – Resources

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Page created 20 April 2013
Page last updated 9 October 2019