Wheat Fiber Arabinoxylan and Prebiotic Activity!!!

Arabinoxylan (AX) is the major component of dietary fiber in cereal grains. Arabinoxylan (AX) is a hemicellulose that has a xylose backbone with arabinose side chains. As a major component of dietary fiber, it is found in many cereal grains. For example, wheat grain, which is composed of an outer layer of bran and an inner layer of endosperm, is a rich source of AX.

AX is difficult to extract from wheat bran but can be produced from wheat endosperm during the commercial processing of wheat flour. When wheat flour is processed to produce starch and gluten, the fiber component, which is mainly AX, is left in the byproduct. AX-rich fiber appears to act as a rapidly fermentable, soluble fiber.
Prebiotics are non-digestible food ingredients that stimulate the growth and activity of bacteria in the digestive system which are beneficial to the health of the body. They were first identified and named by Marcel Roberfroid in 1995. They are considered a functional food. Typically, prebiotics are carbohydrates (such as oligosaccharides), but the definition may include non-carbohydrates. The most prevalent forms of prebiotics are nutritionally classed as soluble fiber. To some extent, many forms of dietary fiber exhibit some level of prebiotic activity.

A study published in the British Journal of Nutrition examined tolerance and prebiotic activity of wheat fiber arabinoxylan consumption by healthy human subjects. This randomized, placebo-controlled cross-over study involved 20 participants who consumed 10 grams of arabinoxylan-oligosaccarides (AXOS) daily for 3 weeks with a 4 week wash-out period in between. Blood samples were taken before and immediately after each intake period. Also, urine was collected over 48 hour period for analysis and feces were collected over 72 hour period for analysis. After 2 and 3 weeks of AXOS intake as well as after 3 weeks of placebo, the levels of bifidobacteria were significantly increased. AXOS had much more of an effect on bifidobacteria than that of placebo. The researchers concluded that AXOS was a well-tolerated prebiotic at the dose of 10 grams daily and that AXOS intake increases bifidobacteria.1

1 Cloetens L, Broekaert WF, Delaedt Y, et al. Tolerance of arabinoxylan-oligosaccharides and their prebiotic activity in healthy subjects: a randomised, placebo-controlled cross-over study. Br J Nutr. 2010;103(5):703-13.