Oligosaccharides are carbohydrates characterized by the simple sugars contained within each. This type of saccharide polymer is located in the amino acid side chains frequently found within vegetables ranging from onions to artichokes and jicama. Oligosaccharides are characterized by their sweet taste and unique mouth feel. These polymers are a source of controversy in the nutritional community because they contain both good and bad reactions within the human digestive system.

Oligosaccharides get their name from the Greek "oligos," which means "a few" and the Latin "sacchar," meaning "sugar". This type of saccharide polymer contains between three and ten simple sugars, also referred to as component sugars. These carbohydrates are an important part of plasma membranes and play a role in the cell-cell recognition within.

Animal plasma membranes are popular places for Oligosaccharides, but this carbohydrate type is most frequently found within plants. Some of the most common plants that house large amounts of Oligosaccharide are Jerusalem artichokes, chicory root, onions, wheat, legumes, asparagus and jicama. The Oligosaccharide is found in a vast array of other plants, but generally in smaller, negligible amounts. Strangely, the food production industry has begun using these carbohydrates as a synthetically added substitute for sugar in many products.

The physical characteristics of Oligosaccharides are their most unique trait. They can be recognized by the mildly sweet flavor they add to whatever plant or animal they inhabit. Another characteristic common to all Oligosaccharides is their particular mouth feel. The soft but firm texture sets them apart from many other types of carbohydrates.

Nutrition experts are torn about the dietary value of Oligosaccharides in digestion. One camp claims the saccharide polymer is beneficial due to its therapeutic role in digestion. When digested, Oligosaccharides stimulate and suppress particular bacteria groups found in the body. These experts claim eating foods rich in Oligosaccharides helps eliminate the number of bad bacteria in the colon and promotes the buildup of helpful bacteria in that organ.

Critics of Oligosaccharides, on the other hand, look at its digestive attributes from a different perspective. This carbohydrate is looked down upon by many because the human body does not break it down properly. Estimates show that nearly 90 percent of all Oligosaccharide-rich foods do not digest in the small intestine and therefore cause a problem for the colon, outweighing any bacterial benefits.