Dietary supplementation of Bifidobacterium longum strain AH1206 increases its cecal abundance and elevates intestinal interleukin-10 expression in the neonatal piglet.

Intestinal microbiota of infants differ in response to gestational age, delivery mode and feeding regimen. Dietary supplementation of probiotic bacteria is one method of promoting healthy populations. We examined the impact of a novel probiotic strain of Bifidobacterium longum (AH1206) on the health, growth and development of neonatal pigs as a model for infants. Day-old pigs were fed milk-based formula containing AH1206 at 0, 10⁹, or 10¹¹ CFU/d for 18 d (n=10/treatment). Differences were not detected in growth, organ weights or body temperatures (P>0.1); however pigs fed the high dose showed a small (2%) reduction in feed intake. Bacterial translocation was not affected as indicated by total anaerobic and aerobic counts (CFU) in samples of spleen, liver and mesenteric lymph nodes (P>0.1). Feeding AH1206 had no effects on fecal consistency, but increased the density of B. longum in the cecum. Ileal TNF expression tended to increase (P=0.08) while IL-10 expression increased linearly (P=0.01) with supplementation. Based upon findings in the suckling piglet model, we suggest that dietary supplementation with B. longum (AH1206) may be safe for human infants based on a lack of growth, development or deleterious immune-related effects observed in piglets.