This is a randomized, double-blind, placebo controlled, cross-over, single centre, 14 week clinical trial on healthy volunteers. Following a two week run-in-period, subjects were randomized, and treatment with synbiotic or placebo for 21 days was given, followed by a 3-week wash-out period before the second treatment period, followed by a another wash-out period. Volunteers completed questionnaires for each period on overall health and well being, stool frequency and consistency and gastrointestinal symptoms. The subjects were asked to collect fecal samples for investigation of microbiological and microbial metabolites before and after three treatment periods. The primary objective of the study is tan increase in fecal butyrate concentration. Secondary objectives are changes in microbiota composition and short-chain fatty acids.