Fig. 1.

Bacteria counts in blood, intestine and mesenteric lymph nodes (MLN) of gnotobiotic pigs. (a) Bifidobacterium choerinum in mono-associated pigs (PR4) or 1 day after subsequent infection with S. Typhimurium (PR4 + LT2). Bifidobacteria were not found in blood. Salmonella reduced the number of bifidobacteria in the colon (P < 0·001). (b) Escherichia coli Nissle 1917 in mono-associated pigs (EcN) or 1 day after subsequent infection with S. Typhimurium (EcN + LT2). E. coli was not found in blood. Its numbers were not influenced by Salmonella. *P < 0·05; **P < 0·01; ***P < 0·001.