Abstract
The cecal bacteria and short-chain fatty acid concentrations were determined in ICR mice that were fed a purified diet with 2.5% galactosyllactose (GL) or 2.5% lactose and that were given drinking water containing GL (0%, 2%, or 4%) and a standard purified diet. In mice fed a 2.5% GL diet, staphylococci significantly decreased in number (p< 0.001) compared to animals fed a 2.5% lactose diet. Although the numbers of other bacterial groups showed no significant changes by GL feeding, the rate of bifidobacteria to the total bacterial counts was two times larger in the GL-fed mice than the lactose-fed animals. Propionate and butyrate concentrations significantly increased in the GL-fed animals (p< 0.01-0.001) compared to those in the lactose group. Animals given GL in drinking water showed increased concentrations of acetic, propionic and n-butyric acids (p< 0.05-0.01) in proportion to the GL concentrations. In contrast, iso-butyrate and iso-valerate decreased in concentration in the GL groups (p< 0.05-0.01). The possible functions, other than a bifidobacterial growth factor, of GL are discussed.
