 The investigators have completed a study at UCLA studying the effects of XOS on human microbiota. There were three phases including a 2-week run-in period, 8-week intervention period, and a 2-week washout. Thirty two volunteers were randomly assigned to take a supplement containing 1.4 g XOS 1.4g XOS 70P, 2.8 g XOS 2.8g XOS 70P or placebo. 