The concept of FODMAPs was first published in the early 2000’s, and since then the low FODMAP diet has been used as an intervention for IBS to reduce gas related signs and symptoms. This article will explain why gas in the digestive tract is in fact necessary for a healthy gastrointestinal system. So let’s break down what FODMAPs are, and why they’re not always the bad guy.

What are FODMAPs?

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. They are short-chain carbohydrates (sugars) that are not completely digested or absorbed in our intestines. Rather than being absorbed, they are fermented down by the bacteria in our digestive tract.

Why are FODMAPs important?

The bacteria in our digestive tract, also known as microbiota, need a job to do and their job is to ferment down fibres. We need a variety of fibres to feed our microbiota, otherwise we may lose quantity and species of gut bacteria. Our microbiota use fermentable fibres as fuel to survive, and this includes FODMAP foods.

Not only do we need vibrant microbiota, but the fermentation process itself is important, as it results in the production of short chain fatty acids (SCFAs) and gases. The major SCFAs produced are acetate, propionate, and butyrate, and each of these three gasses play a role in keeping a healthy digestive ecosystem.

Butyrate is the main energy source for our intestinal cells and has beneficial effects on glucose and energy regulation. Propionate is transferred to the liver, where it breaks down non-carbohydrate sources into glucose and regulates satiety signalling. Acetate is the most abundant SCFA and is involved in cholesterol metabolism as well as playing a role in appetite regulation.

Interestingly the microbiome can change in just six weeks! So research at the moment is looking at whether 6 weeks on a low FODMAPs diet is enough to negatively impact the microbiome. At this stage it's thought to reduce bacterial count but not diversity.

Where are FODMAPs found?

Most foods contain some level of FODMAPs, but below is a list of some common foods that are high in FODMAPs:

Fruits: Apples, apricots, avocado, blackberries, cherries, canned fruit, dates, dried fruit, figs, mangoes, pears, peaches, plums, watermelon.

Vegetables: Artichokes, asparagus, broccoli, beetroot, brussels sprouts, cabbage, cauliflower, garlic, leeks, mushrooms, onions, shallots, snow peas.

Legumes: Beans, chickpeas, lentils, red kidney beans, baked beans, split peas, soybeans.

Grains: Barley, bread, biscuits, breakfast cereals, crackers, muesli, pancakes, pasta, rye bread, tortillas, wheat.

Meat, poultry & fish: marinated meats, processed meats (sausage, salami).

Dairy products: Ice cream, milk (from cows, goats and sheep), most yogurts, soft and fresh cheeses (cottage, ricotta, etc), sour cream, whey protein supplements.

Beverages: Beer, fortified wines, fruit juices, milk, soft drinks, soy milk.

Sweeteners: Fructose, high fructose corn syrup, honey, mannitol, sorbitol, xylitol.

Why would one do the low FODMAPs diet?

The low FODMAPs diet is a common tool for reducing IBS symptoms and SIBO symptoms. When FODMAPs reach the small intestine, they move slowly, attracting water. When they pass into the large intestine, FODMAPs are fermented by gut bacteria, producing gas as a result. The extra water and gas cause the intestinal wall to stretch and expand. Since people with IBS have a highly sensitive gut, this expansion of the intestinal wall can cause exaggerated sensations of pain and discomfort.

Therefore we can see how removing high FODMAP foods works as a symptomatic relief tool, and for some people experiencing dramatic discomfort and debility in their day-to-day life, this is a welcome reprieve!

How should one do the low FODMAPs diet?

The most important thing to remember is the low FODMAP diet is a short term tool. It’s a 2 - 6 week dietary intervention, designed to reduce symptoms.

While doing the low FODMAP diet, treatment should be focused on fixing the underlying cause of the digestive issues. Just taking away high fodmap foods is not enough.

Some underlying causes that may need to be worked on include:

• Supporting digestive enzyme capacity

• Reducing opportunistic bacteria

• Increasing beneficial bacteria

• Healing the gastrointestinal lining

If low FODMAPs is something you want to try, I would suggest implementing it under the guidance of a practitioner, and working on underlying digestive issues at the same time.

The Monash FODMAP app is also a useful support.

Reintroduction phase

If you would like to see a blog on how to complete the FODMAP reintroduction phase, please leave a comment below.

If you are experiencing digestive symptoms and would like individualised support, please get in touch by booking in a Discovery Call or Initial Session here.

References

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390324/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019579/
https://www.bmj.com/content/361/bmj.k2179
https://www.monashfodmap.com/about-fodmap-and-ibs/high-and-low-fodmap-foods/