“Fructooligosaccharides (FOS) also sometimes called oligofructose or oligofructan, are oligosaccharide fructans, used as an alternative sweetener. FOS exhibits sweetness levels between 30 and 50 percent of sugar in commercially-prepared syrups. It occurs naturally, and its commercial use emerged in the 1980s in response to consumer demand for healthier and calorie-reduced foods.”
“Because of the configuration of their osidic bonds, fructooligosaccharides resist hydrolysis by salivary and intestinal digestive enzymes. In the colon they are fermented by anaerobic bacteria. In other words, they have a lower caloric value, while contributing to the dietary fiber fraction of the diet. Fructooligosaccharides are more soluble than inulins and are, therefore, sometimes used as an additive to yogurt and other (dairy) products. Fructooligosaccharides are used specially in combination with high-intensity artificial sweeteners, whose sweetness profile and aftertaste it improves.”
“FOS has been a popular dietary supplement in Japan for many years, even before 1990, when the Japanese government installed a “Functionalized Food Study Committee” of 22 experts to start to regulate “special nutrition foods or functional foods” that contain the categories of fortified foods (e.g., vitamin-fortified wheat flour), and is now becoming increasingly popular in Western cultures for its prebiotic effects. FOS serves as a substrate for microflora in the large intestine, increasing the overall gastrointestinal tract (GI Tract) health. It has also been touted as a supplement for preventing yeast infections.
Several studies have found that FOS and inulin promote calcium absorption in both the animal and the human gut. The intestinal microflora in the lower gut can ferment FOS, which results in a reduced pH. Calcium is more soluble in acid, and, therefore, more of it comes out of food and is available to move from the gut into the bloodstream.
FOS can be considered a small dietary fibre with (like all types of fibre) low caloric value. The fermentation of FOS results in the production of gases and acids. The latter provide some energy to the body.
All inulin-type prebiotics, including FOS, are generally thought to stimulate the growth of Bifidobacteria species. Bifidobacteria are considered “friendly” bacteria. This effect has not been uniformly found in all studies, both for Bifidobacteria and for other gut organisms. FOS are also fermented by numerous bacterial species in the intestine, including Klebsiella, E. coli and many Clostridium species, which are considered less-friendly bacteria in the gut. These species are responsible mainly for the gas formation (hydrogen and carbon dioxide), which results after ingestion of FOS. Most people can eat 5-10 grams of FOS without gaseous discomfort, whereas others have problems with 1 gram. The estimated optimal dose for adults is around 5-10 gram/day.”