Structure of the carbohydrate compounds used for primary and secondary screening and number of hit clones isolated from the fecal (F) and the ileum mucosa (I) libraries.

aXOS, xylo-oligosaccharides; FOS, fructo-oligosaccharides; GOS, galacto-oligosaccharides.bClones positive on fructo-oligosaccharides were further assayed for inulin degrading activity.cClones positive on lactulose (I library) and those identified by screening the entire F library (136, 000 clones) on AZCL-galactan were further assayed on galacto-oligosaccharides.dNT: non tested.eScreening steps: 1, high-throughput primary screen; 2, HPAEC-PAD based secondary screen.