Characterization of Lactic Acid Bacteria and Other Gut Bacteria in Pigs by a Macroarraying Method NARUT THANANTONG, SANDRA EDWARDS, AND OLIVIER A.E. SPARAGANO Newcastle University, School of Agriculture, Food and Rural Development, Newcastle upon Tyne, NE1 7RU, United Kingdom ABSTRACT: Lactic acid bacteria (LAB) consist of many genera, Gram- positive, and nonspore-forming micro-organisms; some members being used as probiotics while some others have negative effects on pig health. Bacterial species in the gastrointestinal tract can produce antibacterial substances, reduce serum cholesterol in their host, or can be responsible for growth reduction, diarrhea, and intestinal epithelial damage. It is therefore important for the pig industry to evaluate the impact of food and farm management on the presence of “good” or “bad” bacteria and the risk for consumers. This articles focuses on the molecular identifica- tion of gut microflora species following different diets given to pigs in UK and correlating the data on growth, health, and welfare. First of all, pig feces were individually collected from sows before and after farrowing and also from piglets before and after weaning over several months. Bac- teria colonies were grown on MRS agar plates from feces and DNA was extracted (QIAamp DNA stool kit) and amplified using 16S rDNA (27f and 519r) primers. DNA sequencing and sequence alignment allowed us to identify species-specific zones, which were used as probes in a macroar- ray system also known as reverse line blot hybridization. Some probes were found to be species specific for the following species: Lactobacil- lus acidophilus, L. animalis, L. gallinarum, L. kitasanotis, L salivarius, Streptococcus alactolyticus, S. hyointestinalis, and Sarcina ventriculi. Ac- tual studies are now focusing on the impact of diets of the microflora in different gut parts and at different stages of the animal’s life. KEYWORDS: pig; gut; Lactobacillus; diet; RLB Address for correspondence: Dr. Olivier A.E. Sparagano, School of Agriculture, Food and Rural Development, Newcastle University, Agriculture Building, Newcastle upon Tyne NE1 7RU, UK. Voice: 44-191-2225071; fax: 44-191-2226720. e-mail: Olivier.sparagano@ncl.ac.uk Ann. N.Y. Acad. Sci. 1081: 276–279 (2006). C  2006 New York Academy of Sciences. doi: 10.1196/annals.1373.037 276