Fig. 6

Comparison of the Bifidobacterium number and metabolic responses after in vitro batch fermentation. The faecal slurries of midlife (M) and young (Y) groups were subjected to in vitro fermentation of starch (STA) and inulin (INU). The Bifidobacterium numbers are determined by qPCR (a). The metabolic responses including SCFAs (b-h), gas productions (i) and degradation rate of the sole carbohydrate (j) were determined. The SCFAs were determined by GC. The total SCFAs (b) is the sum of 6 individual acids including acetate (c), propionate (d), butyrate (e), isobutyrate (f), valerate (g) and isovalerate (h). The gas production after fermentation was measured by the air pressure difference of the vial (i). The degradations of starch and inulin after fermentation were detected by TLC (j)