INULIN AND OLIGOFRUCTOSE AS PREBIOTICS

The prebiotics like inulin and oligofructose can be classified as carbohydrates that resist both hydrolysis by mammalian digestive enzymes and absorption in the small intestine, but is partly metabolized and fermented by the colonic microbiota. They can be classified as dietary fibre and labeled as consumer food products.

Inulin and oligofructose, being a mixture of relatively short chain molecules, have no water holding capacity. However, being water soluble and hydroxyl rich molecules, they exert an osmotic effect that is likely to be the origin of the laxative effect which occurs at high doses. But there are some points that clear inulin and its controlled hydrolysis product, oligofructose, as dietary fibre. They are

• They are parts of edible plants;
• They are carbohydrates that are composed of a mixture of various oligosaccharides and / or polysaccharides;
• They resist hydrolysis by human digestive enzymes; and
• They do not appear to be significantly absorbed in the small intestine, except possibly for the very short chain oligosaccharides are absorbed, they are not metabolized in the body and are excreted as such in the urine as is intravenously injected inulin having degree of polymerization (DP-30) that is classically used in the medical practice for measuring either extracellular fluid volume or the renal glomerular filtration rate. It is reported that approximately, 1% of the oligofructose that disappears from the small intestine is recovered in the urine.

The recommended intake of Prebiotics

The dietary intake of oligosaccharides is difficult to estimate but it mane range from 3 to 13 g per day per head depending on the population. The average daily consumption of inulin and oligofructose has been estimated to be 2-8 g in the U.S and 3-11 g in Europe. Clinical trials with humans indicate that daily intake of 5 – 20 g of inulin and oligofructose selectively promote the growth of bifidobacteria. Although no standards are available for the intake of prebiotics (inulin and oligofructose), a minimum of 5 g per day is recommended.

Prebiotics – Their health story

Selective fermentation of prebiotics by probiotic microorganisms must result in a healthier composition of the gut microflora and should induce luminal or systemic effects, beneficial to the host. All fibres act as prebiotic in varying degrees. Fibre consumption benefits our intestinal ecosystem, improve immunity and overall health. Prebiotics, especially, inulin helps in the improvement of mineral absorption like zinc and copper, improve calcium bioavailability, results in better lipid metabolism, improved immuno stimulation and helps in combating lactose intolerance.

Various studies have revealed their protective role in preventing colon cancer and coronary heart diseases. Prebiotic agents have significant clinical beneficial effects in the prevention and management of abnormalities of gastro intestinal tract. Prebiotics also aid in treating various disorders like necrotizing enterocolitis, traveler’s diarrhea, allergic colitis, inflammatory bowel diseases and in paediatric gastrointestinal disorders, by increasing the biomass of probiotics and stool bulking.