Description | L-Arabinose is a pentose with a sweet taste and one of the most abundant components released by complete hydrolysis of non-starch polysaccharides (NSP) of vegetable origin. However, NSPs are complicated compounds from the point of view of both physical structure and chemical composition, and they include cellulose, hemi-cellulose, pectin and oligosaccharides. It is well recognized that NSPs are resistant to the digestive enzymes and pass to the hind-gut where microbial degradation takes place. When L-Arabinose is ingested in a digestible form, it is absorbed from the intestinal tract but at a lower rate than glucose. A portion of the ingested L-Arabinose is excreted in the urine. Although widely present in nature, L-Arabinose is rarely used, and its physiological effects in vivo have received little attention. L-Arabinose selectively inhibits intestinal sucrase activity in a noncompetitive manner and suppresses the plasma glucose increase due to sucrose ingestion. Because the intestinal absorption of sucrose is inhibited in the presence of L-Arabinose, the absorption of sucrose should be reduced by arabinose ingestion. Most of the studies reported so far on the absorption and utilization of L-Arabinose relate to omnivore animal species other than humans. In a rare case of two autistic brothers that were not associated with any known metabolic disease, it was found the median value for their urine samples was 179 umol/mmol creatinine of L-Arabinose, nearly six times greater than normal children. (PMID: 11238761, 8931641, 1390604, 7628083) |