Bean husk, an agricultural by-product having functionality in animal nutrition and health

摘要

Bean husk is an agricultural by-product abundantly available in the world and considered a new feed source candidate for various animals. Although bean husk has been reported as a fiber supplement for ruminant animals, evaluation of its functional property with respect to nutrition and health in monogastric animals is quite limited. A series of studies using chickpea (Cicer arietinum) husk, lablab bean (Dolichos lablab) husk and soybean (Glycine max) husk were conducted to evaluate the functional properties of the husk in monogastric animals. First, we evaluated dietary supplementation (5%) of chickpea husk using rats and found that rats fed chickpea husk showed lower levels of cholesterol and thiobarbituric acid reactive substances (TBARS) in blood by its polyphenolic component. Second, we evaluated lablab bean husk or soybean husk supplemented (5%) diet using rats and found that rats fed either husk showed increased cecal short chain fatty acid (SCFA) than those on cellulose (control) and starch (negative control). Lablab bean husk increased cecal abundance of Akkermansia, while soybean husk increased that oflactobacilli according to qPCR and Miseq analyses. Both types of bean husk were found to contain oligosaccharides and these might selectively stimulate the growth of beneficial bacteria and improve hindgut fermentation. Cellulose- or soybean husk-supplemented (5.6%) feed was given to Shiba dogs. Dogs fed soybean husk showed higher SCFA level and higher abundance oflactobacilli and bacterial groups including butyrate producers in their feces than those fed cellulose.Based on these, three different types of bean husk tested in the present study were suggested as a functional feed ingredient for possibly promoting blood or gut health of monogastric animals.