The fecal metabolic products and the constitution of the microbial population of fresh feces were compared between pigs given a diet supplemented with dietary microbes ("Lactohirox") and pigs given a non-supplemented diet. At 60 days of age after birth, the total volatile fatty acids (VFA) concentration in the feces of pigs given a diet supplemented with dietary microbes was significantly higher than the pigs given a non-supplemented diet. And also, the VFA composition in the feces was different between the pigs given a diet supplemented with or without dietary microbes. However, at 90 days of age after birth, the VFA concentration and composition in the feces were not different between the pigs given a diet supplemented with or without dietary microbes. For the constitution of microbial populations, at 60 days of age after birth the cell density of veillonellae was lower in the feces of pigs given a diet supplemented with dietary microbes than in the pigs given a non-supplemented diet. At 90 days of age after birth, streptococci were more abundant in the feces of pigs given a diet supplemented with dietary microbes, as compared with the pigs given a non-supplemented diet. At 90 days of age after birth, the predominant bacteria in the feces of pigs given a diet supplemented with dietary microbes were Bacteroides spp. and Lactobacillus spp., while those in the pigs given a non-supplemented diet were Bacteroides spp. and Fusobacterium spp. For the species composition of lactobacilli isolated as the predominant bacteria, L. gasseri was most abundant in the feces of pigs given a diet supplemented with dietary microbes, and L. acidophilus was most abundant in the pigs given a non-supplemented diet.