Many people think it’s normal to experience bloating after meals. But regular or constant bloating is usually a sign that your gut flora is out of balance.

As many as 1 in 5 Australians are diagnosed with IBS. By now you already know about the leading cause of IBS, which is Small Intestinal Bacterial Overgrowth (SIBO).

Whilst trillions of bacteria are normally found in the large intestine, SIBO occurs when there is bacterial overgrowth in the small intestine.

Living with IBS is a huge struggle for many people as it can make meal preparation (and eating out!) a bit of a minefield, especially when you don’t know which foods will cause you to bloat.

So what actually causes bloating?

Bloating occurs when we eat foods that feed the bacteria which are overgrown in the small intestine. The bacteria ferment these foods, thereby producing gases such as hydrogen and methane.

Temporary diet modification is an important part of treating SIBO, as we need to restrict the foods that feed those bacteria whilst we work on healing the gut.

So which foods commonly cause bloating?

Here are the top trigger foods which can feed bacterial overgrowth in the small intestine, and thereby cause bloating:

• Grains. Wheat is the main culprit as it is particularly high in gluten, which also causes leaky gut (where the lining of your gut becomes compromised, allowing toxins, microbes and undigested food particles to enter the blood stream). It’s important to remember that all grains feed the intestinal bacteria. This includes rye, spelt, barley, oats, rice, corn, quinoa, buckwheat, bulgur, and of course goods made with grains (pasta, bread, cakes, biscuits, crackers, cereals etc).
• Legumes. Beans, lentils, chickpeas etc are particularly high in fibre which is healthy, but causes issues in people with SIBO. Soaking legumes before cooking them makes them more digestible by activating enzymes and removing phytic acid, but they are best avoided for a while until the SIBO is eliminated.
• Dairy products. Dairy contains lactose, a sugar which many people have trouble breaking down in the body. To digest lactose efficiently, we need adequate levels of lactase, an enzyme which naturally diminishes with age. It is estimated that approximately 65% of the global population has a reduced ability to digest lactose.
• Starchy vegetables. Whilst root vegetables are an important part of the diet, they cause problems for people with SIBO because they are very starchy. This includes white and sweet potatoes, parsnips, yams, taro, cassava, beetroot and pumpkin.
• Prebiotics. Prebiotics are a special form of dietary fiber which cannot be digested by humans, but is fermented by intestinal bacteria. Prebiotic foods include onions, garlic, leeks, asparagus, carrots, chicory root, radishes and Jerusalem artichokes. This is why many people with SIBO experience a worsening in their symptoms when they take fibre products or prebiotics.
• Certain fruits. Canned fruit, apples, apricots, blackberries, figs, mango, nectarines, peaches, pears, persimmons, plums and watermelon are all high in fructose, a simple sugar which feeds bacteria. Many people are diagnosed with fructose malabsorption, but few know that this condition goes hand-in-hand with SIBO.
• Certain nuts and seeds. Peanuts, chia seeds and flaxseeds are a no-go for people with SIBO. Alternatives are almonds, hazelnuts, macadamias, pecan, walnuts, pepitas, sunflower seeds, sesame seeds, coconut and pine nuts – but even these need to be eaten in moderation.
• Food additives. Starches and sugars are often added to foods to make them more palatable. It’s important to check ingredient labels for these hidden starches as they feed the same bacteria. Look out for arrowroot, tapioca, artificial sweeteners such as xylitol, maple syrup, maltodextrin, guar gum etc. Common sources of added starches are canned soups and any packaged foods including stocks and sauces.

If you experience bloating within an hour of eating (especially after eating the foods above) chances are you may have SIBO. The likelihood increases if you also experience diarrhoea and/or constipation, abdominal pain, burping, wind, reflux, food sensitivities and body aches.

If you haven’t already done so, take this free two-minute quiz to find out if SIBO is causing your symptoms.