A double blind crossover study was conducted involving healthy female university students. The subjects were instructed to drink on separate days 200 mL of a malt drink containing 360 mg calcium carbonate with or without 3 grams of scFOS. Each drink was spiked with 48C stable isotope tracers. Urine samples were collected at specified time intervals for assay. Cumulative urine outputs appear in the following image.
The results show that significant increases occur at the 4 hour time interval and times thereafter. The increase can be explained by the fact that small intestine transit time is fairly well established at 3 hours and on reaching the colon scFOS is fermented by resident beneficial microflora into short chain fatty acids. The resulting lower pH microenvironment results in enhanced calcium absorption.
Uenishi K et al (2002) Effects of malt drink containing fructooligosaccharides on calcium absorption and safety of long-term administration. The Japanese Journal of Nutrition and Dietetics 60(1)11-18.