Eleven individuals with low fecal bifidobacteria counts consumed one bottle (110 mL) containing a beverage with 2.5 g of galacto-oligosaccharides daily for two weeks. There was a two-week nonconsumption period before and after the consumption period. During the consumption period, fecal samples were collected once at the end of week one and week two, and during the nonconsumption periods, samples were collected once on the final day, for a total of four fecal samples, which were then analyzed.

Thirty-two healthy individuals with a tendency for constipation were divided into two groups and given either a beverage containing 5.0 g of galacto-oligosaccharides (hereinafter a galacto-oligosaccharide beverage) or a placebo beverage as one bottle (110 mL) daily for two weeks. After a two-week nonconsumption period, the beverages were switched between groups, and they consumed either the placebo or the galacto-oligosaccharide beverage as one bottle (110 mL) daily for two weeks. Bowel movement frequency was also analyzed for 20 subjects with mild constipation (subjects with three to five bowel movements per week).