Biodegrading Wheat Bran with Agaricus blazei and Its Effects on Intestinal Development Identified with Mice
SHEN Heng-sheng, CHEN Jun-chen, LI Yi-bin, Ting Zhou
Agaricus blazei Murill is a well known edible/medicinal mushroom used for immune-nutrient food therapies. The biodegradation of different substrates with this fungus may result in different metabolites and degraded compounds, which may enrich the function of the food therapies. In this study, soluble compounds from the culture of A. blazei grown in liquid media with whole wheat bran and its water filtrate, respectively, were compared. Total soluble sugar, arabinoxylan, protein, and amino acids were significantly higher in the fungal culture resulted from the medium with whole wheat bran (43.54, 1.56, 0.59, and 2.19 mg mL-1, respectively) than that from the medium with the bran filtrate (17.28, 0.37, 0.13, and 1.13 mg mL-1, respectively). The biodegraded wheat bran with cultured mycelia was fed to Mus musculus Linnaeus as supplementation or as dietary fiber exclusive ingredient. As non-specific food therapies, feeding effects on mice intestinal development were indicated indirectly in growth performance, intestinal absorption and serum parameters. Compared to feeding uncultured wheat bran, feeding mice with culture mixes of A. blazei resulted in remarkably increase in villus height and villus height/crypt depth ratio, which were increased by 25.4 and 31.0%, respectively, when applied as supplementation, and by 44.3 and 43.4%, respectively, when applied as dietary fiber. These increases are concomitant with the higher level of D-xylose in blood serum about 16.9 and 29.2% as supplementation and dietary fiber, respectively. The results implying that culturing A. blazei with whole wheat bran enhanced extracellular metabolism of the fungus and extensive degradation of wheat bran insoluble fibrous compounds. Furthermore, feeding the culture mix including metabolites and degraded wheat bran improved intestinal villus development, proving the nutritional benefits of the A. blazei mycelial cultures.