A new probiotic strain of Bifidobacterium longum subsp infantis CECT 7210 (Laboratorios Ordesa, S.L.) was evaluated in 2 oral challenges against Salmonella Typhimurium or enterotoxigenic E. coli (ETEC) K88. Seventy-two piglets, 21 and 24 (±2) days old were used in each trial. Animals were distributed in 24 pens and 4 groups in a 2 × 2 design: with and without probiotic and oral challenge. The animals were fed a plain diet and the probiotic was administered orally on a daily basis (10⁹ cfu/d). After a 1-week adaptation, a double oral inoculation was done with Salmonella Typhimurium (2 × 10⁹ and 6 × 10⁹ cfu/day) (trial 1) or ETEC K88 (5 × 10⁹ and 6 × 10¹⁰ cfu/day) (trial 2). Intake, live weight, fecal excretion of the pathogen, fecal consistency and rectal temperature were registered. Results were analyzed with a GLM and adjusted by Tukey. Microbiological frequencies were analyzed by Fisher. On d 4 and 8 post inoculation (PI), blood samples were obtained from one animal from each pen to assess inflammatory response (TNF-α and Pig-Map), being euthanized afterward for intestinal content and ileal scrapings sampling for microbiological and fermentation products analysis. Performance parameters were affected by the Salmonella challenge with reductions in feed intake and gains (ADG 118 g challenge animals vs. 209 g, P < 0.001), but not by E. coli (ADG 114g challenge animals vs. 120 g, P = 0.801). No significant differences were found related to the probiotic. The challenge also got worse fecal consistency (P < 0.001) and increased plasma TNF-α levels (P < 0.05). Although the probiotic did not ameliorate these clinical signs it was able to reduce fecal excretion of Salmonella (especially at d 3 PI; P = 0.043) and diminished the percentage of animals with countable (>10⁵cfu/g) coliforms in ileal scrapings at d 4 PI (58 vs. 91%; P = 0.010). A consistent interaction was seen in both trials for colonic short chain fatty acids (SCFA), were the probiotic increased their concentration in the control animals but not in the challenged ones. Results indicate administration of the probiotic can reduce intestinal colonization by Salmonella and ETEC K88 in mild enteric processes.