Prebiotics are short chain carbohydrates that are nondigestible by digestive enzymes in humans and selectively enhance the activity of some groups of beneficial bacteria. In the intestine, prebiotics are fermented by beneficial bacteria to produce short chain fatty acids. They have a wide range of health benefits in the large intestine like reduction of cancer risk and increase calcium and magnesium absorption. Connolly et al., (2010) described that populations of different beneficial bacteria such as Bifidobacterium genus, the Lactobacillus–Enterococcus group and the Atopobium group can be significantly increased after konjac glucomannan hydrolysate fermentation. Fermentation of konjac glucomannan and hydrolyzed konjac glucomannan may protect against oxidative stress in the human colon (Wang et al., 2008). Mizutani and Mitsuoka (1982) evaluated the effect of 10% konjac based diet on total fecal microflora count in 30 male C3H/He mice. Among the 11 specific types of microflora examined, two were found significantly changed: the frequency of bifidobacteria increased from 30% in control mice to 100% in konjac flour-fed mice and the log count of enterobacteriaceae increased from 6.0 in control mice to 6.6 in konjac flour-fed mice. A similar study was also conducted by Elamir et al. (2008) to examine the effects of konjac glucomannan oligosaccharides (KGMO) on the gut microflora of mice. They described that the KGMO was able to significantly reduce fecal Clostridium perfringens and Escherichia coli counts.