Everyone has heard of it, but no one knows exactly what it is: irritable bowel syndrome. What the syndrome has to do with sugar consumption.
“I eat such a healthy diet, why do I always have gastrointestinal complaints?” This is one of the most frequent questions Daniel Pohl hears during his consultation. The gastroenterologist treats patients with irritable bowel syndrome and knows what can trigger it: “According to the literature, almost half of all people with irritable bowel syndrome suffer from wheat intolerance. Almost 40 percent cannot tolerate milk and fatty foods. Other known triggers are onions and garlic.”
Most triggers contain sugar
“Very often we are dealing with an intolerance to fermentable sugar,” says Daniel Pohl. This is sugar that can ferment in some form in the gastrointestinal tract. For example, lactose, fructose or more complex fructose-based sugars such as fructans. “Sugar alcohols are often added to food,” says the gastroenterologist. “These are also fermented in the digestive tract.” Experts refer to them as FODMAPs: fermentable oligo-, di- and monosaccharides and polyols.
Unpleasant by-products
To understand why FODMAPs cause discomfort, you need to understand the mechanism of fermentable sugars in the gastrointestinal tract: When you eat fermentable sugars, they are transported into the stomach and then into the small intestine. They should be taken in there. “If there are too few enzymes in the small intestine – for example, lactase to break down lactose – or if you consume too much sugar, the sugar is not absorbed and instead moves on to the large intestine,” explains Daniel Pohl. This produces various by-products: some that are important for the intestines, but also hydrogen, a gas that bloats the intestines. “The sugars are also osmotically active, which means they draw water into the intestinal lumen,” says Daniel Pohl. This explains why some people suffer from diarrhea, stool irregularities, abdominal pain, flatulence and diarrhea after consuming FODMAPs.
Peripheral or central hypersensitivity
Why do some people suffer from stomach problems after consuming sugars and others do not? Daniel Pohl knows: “A certain sensitivity is required. From a certain dose of FODMAP, everyone suffers from gastrointestinal complaints. If you eat a kilo of onions, you will notice it.” Studies have shown that irritable bowel syndrome patients have more symptoms than average at lower doses of FODMAP. Why? Two mechanisms are known: peripheral and central hypersensitivity. People with peripheral hypersensitivity feel strains in the intestine much more quickly. It is also assumed that they suffer from micro-inflammation and that immunogenic and hormonally controlled processes are responsible for this. The central nervous system plays a role in central hypersensitivity: “If you know in advance that you will get a stomach ache when you eat an apple, you expect it. You are conditioned to it,” explains Daniel Pohl. The body then actually reacts with the expected symptoms.
Hydrogen in exhaled air
Apart from the symptoms, how is hypersensitivity medically diagnosed? “In our consultation, the first thing we do is check whether other illnesses are already present and what tests have already been carried out. Then we analyze the blood values to rule out any allergic tendencies,” says Daniel Pohl. Patients also receive a drink that contains fat, protein, volume and fermentable sugars. For three hours after admission, patients must write down their symptoms and rate them according to their intensity (strength). At the same time, the doctors measure the hydrogen present in the breath. As soon as this rises, fermentation begins in the body. If the symptoms occur at the same time as fermentation, this means that those affected are reacting to the fermentable sugars. “This allows us to differentiate whether the gastrointestinal problems are food-related or not,” explains Daniel Pohl. This result helps to select the right therapy.
Nutritional advice can make a big difference
Practically all irritable bowel syndrome patients receive an appointment with the nutritional counseling service. “Those affected must eat a FODMAP-free or at least low-FODMAP diet for several weeks. And still consume sufficient fats, proteins, etc. It’s about the diet as a whole,” says Daniel Pohl. Studies have shown that a FODMAP-free diet contains fewer calories. This is one reason why nutritional advice is absolutely essential for irritable bowel syndrome caused by food intolerance. However, Daniel Pohl believes it is important not to demonize sugars: “You shouldn’t panic, even if you do consume sugars. It won’t kill you. This is an important difference to allergological and immunological reactions. Take a relaxed approach.”
