Relative abundance of major bacteria in BALB/c mice small intestine distinguished by groups and feeding periods. (A) Family level bacteria in the small intestine of BALB/c mice fed an experimental diet for 4 weeks (B) Family level bacteria in the small intestine of BALB/c mice fed an experimental diet for 8 weeks. AIN4: CON4, MAIN4: POS4, MIE4: MWE4, AIN8: CON8, MAIN8: POS8, MIE8: MWE8