Fructan is a type of carbohydrate that belongs to the category of dietary fibers. It is composed of chains of fructose molecules linked together by a specific type of bond known as a β(2-1) glycosidic bond. Fructans occur naturally in a variety of plants, particularly in certain vegetables, fruits, and grains. They are commonly found in foods such as wheat, onions, garlic, artichokes, bananas, and asparagus.
Fructans are classified into two main types: inulin and fructo-oligosaccharides (FOS). Inulin is a longer chain fructan that can contain several hundred to a thousand fructose units. On the other hand, FOS is a shorter chain fructan that typically contains two to ten fructose units.
These carbohydrates are not easily digested by the human digestive enzymes in the small intestine, which means they pass through to the large intestine largely intact. Once in the large intestine, fructans are fermented by the bacteria present in the gut. This fermentation process produces short-chain fatty acids and gases, such as carbon dioxide, hydrogen, and methane.
Fructans have been associated with both positive and negative health effects. On the positive side, they can serve as a prebiotic, providing nourishment for beneficial gut bacteria. This can potentially improve the balance of gut microorganisms and support overall digestive health. However, for individuals with certain conditions like irritable bowel syndrome (IBS), fructans can be poorly absorbed and may cause symptoms such as bloating, gas, and abdominal discomfort.
In summary, fructan is a type of carbohydrate commonly found in certain fruits, vegetables, and grains. It is a fiber that is fermented by gut bacteria in the large intestine
