Description:Background: The microbiota strongly influences human gut homeostasis and health through its metabolites. The metabolic products of the infant microbiota are strongly influenced by human milk or formula feeding. Human milk contains oligosaccharides (HMOS) that are prebiotic, promoting gut colonization by mutualists. Most human milk contains 2’-fucosyllactose (2’FL) as its principal oligosaccharide, but its abundance varies. The goal of this study was to evaluate the metabolites of cultured stool microbiota in the presence of different prebiotics as an approach to predict prebiotic responsiveness. Our studies find that The response to 2’FL or GOS in baseline fermentation analysis was associated with differences in microbial beta-diversity, suggesting that individual responsiveness to specific prebiotics may be predicted by anaerobic fermentation of their stool samples. Continuous supplementation of prebiotic may prime the gut microbiota to more efficiently utilize this prebiotic.