FODMAPs can be responsible for a lot of unpleasant gut symptoms, which is why we recommend removing all high FODMAP foods from your menu initially. Here is some information that will help you understand a bit more about FODMAPs and why they can cause these symptoms.

IMPORTANT: Not everyone reacts to FODMAPs. If you don't react to these foods, there is no reason to avoid them. This is something you will figure out when you re-introduce foods in the next step. 

FODMAPs are found in the foods we eat. FODMAPs is an acronym for:

Fermentable

Oligosaccharides (eg. Fructans and Galacto-oligosaccharides (GOS))

Disaccharides (eg. Lactose)

Monosaccharides (eg. excess Fructose)

and

Polyols (eg. Sorbitol, Mannitol, Maltitol, Xylitol and Isomalt)

These short-chain carbohydrates can be poorly absorbed in the gastrointestinal tract and can easily be fermented by gut bacteria. These sugars (when malabsorbed) also exert an osmotic effect, increasing fluid movement into the large bowel. The fermentation and osmosis caused by these undigested sugars are a cause of major IBS symptoms such as gas, pain, and diarrhoea.

And while all FODMAPs can potentially factor in the development of IBS symptoms, the relative contribution of different types of FODMAPs varies across ethnic and dietary groups depending on the amount of each in the diet. Additionally, individuals differ in their amount of malabsorption of FODMAPs such as fructose, lactose, and fructans and are therefore more or less sensitive to certain FODMAPs in particular.

SIBO can contribute to the development of FODMAP intolerance. The presence of excess bacteria in the small intestine causes excessive fermentation of these carbohydrates, increasing gas production and allowing for the proliferation of uncontrolled gut bacteria. In other cases, certain individuals may lack adequate enzymes to break down and absorb the fermentable sugars (SIBO can contribute to this as well by damaging the lining of the small intestine) before they reach the colon, contributing to the unpleasant symptoms.

People differ in how well they can tolerate some of the FODMAP’s identified above and some trial and error will be necessary to find out your own level of tolerance. It's also important to note that if you treat SIBO successfully and/or improve your gut health, you should be able to tolerate more FODMAPs than before the treatment.

To improve the way you feel quickly, we recommend avoiding all high FODMAP foods at first, as this will allow you to start feeling better quickly. But if you do not address the overgrowth of bacteria/imbalance of bacteria in your gut, healing will not happen and you will have to avoid these foods for the rest of your life.

EXAMPLES OF FOODS IN EACH FODMAP CATEGORY

HIGH FODMAPS FOODS LIKELY TO CAUSE GUT SYMPTOMS

Fructose: Apple, honey, cherries, figs, mango, pear, plum, watermelon, Jerusalem artichoke, asparagus, sugar snap peas, broad beans

Polyol-Sorbitol: Apple, apricot, avocado, blackberries, lychees, nectarine, peach (white and yellow), pear, plum, corn

Polyol-Sorbitol: Cherries, coconut, broccoli (more than 1 cup)

Polyol-Mannitol: watermelon, cauliflower, snow peas, button mushrooms, sweet potatoes, butternut squash (more than 1/2cup)

Oligo-Fructans: wheat, rye, grapefruits, nectarines, white peach, pomegranate, watermelon, dates, raisins, Jerusalem artichoke, globe artichoke, asparagus (>4 spears), beetroot, garlic, leeks, snow peas, button mushrooms, onions, butternut squash (more than 1/2cup), broccoli (more than 1 cup), pistachio, cashews, split peas

Oligo-GOS: almonds (more than 10 nuts), pistachio, cashews, butter beans, borlotti beans, split peas, beetroots, corn, snow peas, peas (thawed)

LOW FODMAP FOODS LESS LIKELY TO CAUSE GUT SYMPTOMS

Low FODMAPs Fruits: banana (Cavendish), blueberries, cantaloupe, dragon fruit, grapes, kiwi, lime, lemon, oranges, passionfruit, pawpaw, pineapple, raspberry, strawberry,

Low FODMAPs Vegetables: Eggplant, green beans, pepper/capsicum, broccoli (less than 1cup), Brussel sprouts (less than 3 sprouts), cabbage (less than 1 cup), carrots, celeriac, collard greens, bok choy, kale, zucchini/courgette, fennel, leeks (green leaves, for flavouring), radicchio, lettuce, pumpkin, spinach, radish, spaghetti squash (about 1 ½ cup), tomatoes, olives

To learn more:

Download the Monash University FODMAPs App and start familiarising yourself with the different groups of FODMAPs.