Prebiotics are non-digestible food supplements (oligosaccharides) which play an important role in stimulating the growth of beneficial bacteria especially Lactobacilli and Bifidobacteria in the colon of the host. Xylooligosaccharides (XOS) are more effective than other oligosaccharides such as fructo-oligosaccharides as dietary supplements. Chemical methods are preferred to produce XOS mixtures with a wide DP range, while enzymatic methods are preferred in the food or pharmaceutical industries to reduce formation of degradation products. With the growing importance of making fuels fromlignocellulosic biomass (LCM) and the increasing demand for XOS, more opportunities are emerging to utilize xylan-rich component generated in biorefinery into high-value products such as XOS that could further lower the cost of LCM derived biofuels.