“…Bifidobacteria were enumerated using BIM-25 (Muñoa & Pares, 1988;Lapierre et al, 1992;Rada et al, 1999), which is a reinforced clostridial agar base containing polymixin B, tetrazolium red, iodoacetate, kanamycin, and naladixic acid (Sigma-Aldrich, St Louis, MO). Lactobacilli were enumerated using LBS Agar (Difco) plus 200 mL L À1 tomato juice from concentrate (Campbell Soup, Camden, NJ) (Rogosa et al, 1951;Sabine & Vaselekos, 1965). Organisms in the Bacteroides fragilis group were enumerated with Bacteroides Bile Esculin Agar (BBE; Difco).…”