Abstract
In the present study, two experiments were carried out in vitro and in vivo in order to determine physiological properties of 4G-β-galactosylsucrose (lactosucrose: LS) as a bifidus factor. First, effects of LS supplement on short chain fatty acids (SCFA) production, pH, and the numbers of Bifidobacterium, Eubacterium and Bacteroidaceae were investigated using an anaerobic fecal incubation system with or without LS. Results are as follows; (1) Lactate, acetate, propionate, butyrate and valerate were produced from LS, resulting in a fall of pH in the medium.(2) The number of Bifrdobacterium increased in the presence of LS, while those of Bacteroidaceae and Eubacterium decreased. Next, in clinical study, effects of LS50P (containing 51% of LS) intake on fecal microflora, fecal concentration of SCFAs and fecal properties such as fecal weight, moisture and pH were investigated. Nine healthy volunteers were administered LS (0.36g/kg BW/day) for 3 weeks. The following results were obtained; (1) The number and percentage of Bifidobacterium increased significantly, while the percentage of Bacteroidaceae decreased.(2) Fecal weight showed a tendency to increase. Fecal moisture and pH remained unchanged.(3) The subjective feeling of evacuation was improved.(4) The fecal concentration of SCFA significantly decreased on day 14 after LS50P administration. These results demonstrate that LS is a growth-promoting factor for bifidobacteria. It is also suggested that LS ingestion is useful for subjects with constipation. The fact that LS supplement rapidly produced SCFAs in vitro but not in vivo suggests that bifidobacteria-induced SCFAs are readily absorbed through intestinal tract.
