Taken together, our work and the work of others show that inulin, maltodextrin, and xanthan gum are purified MACs that consistently suppress CDI while FOS, 2′-FL, 6′-SL, and LNnT are purified MACs that do not suppress CDI (Fig. 3) (9, 10). This evidence concerns the gene FOS and clostridium difficile infection.