I transformed my gut health after years of agony – after a simple test

What is SIBO?

“SIBO is an overgrowth of bacteria in the small intestine, the tubular organ that connects our stomach to the colon,” explains Dr. Mullan. “Unlike the large intestine, where we need bacteria for a healthy gut microbiome, in the small intestine they can cause a lot of problems.”

These bacteria feast on fermentable foods and then release hydrogen and methane gases that cause bloating and cramping. They also interfere with what Dr. Mullan calls “the housekeeping wave” of our digestive process, slowing digestion and interfering with nutrient absorption. In the worst cases, this can lead to malnutrition and other long-term health problems.

Then there’s the food, waste, and bacteria hanging around, causing various digestive issues—constipation and diarrhea are common—and non-digestive symptoms, like fatigue, brain fog, and rosacea.

The good news is that, as grim as it may sound, SIBO can be definitively diagnosed and treated, unlike its catch-all gut sibling, IBS.

Dr. Mullan’s suspicions were confirmed when, after following a very restrictive diet for 24 hours, a breathalyzer test revealed high levels of methane and hydrogen coming from my small intestine. “A small amount of these gases is normal in the colon,” says Mullan, “but not in the upper part of the digestive tract.”

How is SIBO treated?

The treatment plan is two-fold – with a very restricted special diet and either a two-week course of traditional antibiotics, or – the route deemed most appropriate for me – “herbal antibiotics/antimicrobials”, such as berberine and allicin, as well as probiotics and – once treatment is complete – a supply of supplements to help repair the intestinal lining (glutamine) and decrease inflammation (glutathione).

This phase is affectionately known as the “kill phase” and I can confirm that it is not fun, despite its action movie-sounding name. I had headaches, nausea and felt exhausted. Apparently this is all good – a sign that bacterial overgrowth is being wiped out, so it was also strangely satisfying.

The low FODMAP diet

As for the diet, it’s another acronym, I’m afraid, in the form of the Low FODMAP system, designed at Monash University in Melbourne. FODMAPs (which stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols) are a group of carbohydrates that are either poorly absorbed in the small intestine or impossible to digest. Within these four groups, there are a range of foods to avoid, ranging from fructans – found in wheat, onions and garlic; lactose – present in dairy products; fructose, present in certain fruits; galactans – found in legumes, such as beans and lentils; and polyols – found in some fruits and vegetables such as apples, avocados and mushrooms.

The goal of the diet is to starve the bacteria by reducing starches and fermentable fiber (their fuel), which will also help reduce unpleasant digestive symptoms. It’s a bit like not feeding a gremlin after midnight: don’t feed the bacteria.

I hadn’t heard of FODMAP and it was all a bit of a headache, especially for someone like me who pathologically hates restricting my diet. I felt like I was re-doing my biology GCSEs, just so I could eat.

What’s confusing is the fact that you can eat certain fruits, but not others – kiwi, OK, apple, no, for example. Likewise, vegetables. Don’t eat cauliflower and snow peas, but carrots and potatoes are perfectly fine. With dairy, milk and some soft cheeses are problematic, but butter and hard cheeses are fine.