Intestinal lactose and mineral concentration affect the microbial ecophysiology along the gastrointestinal tract of formula-fed neonatal piglets
R. Pieper, W. Vahjen and J. Zentek
Hyperprolificacyin modern pig breeds has led to increased use of artificial rearing and formula feeding of neonatal piglets, which may change their intestinal bacterial ecophysiology. Here, newborn piglets (n = 8 per group) were fed a bovine milk-based formula (FO) or allowed to suckle their mothers (sow milk [SM]) for2 wk, and digesta samples from the stomach, jejunum, and colon were subsequently analyzed for enzyme activities, bacterial metabolites, and 16SrRNA transcripts of bacterial groups by quantitative real-time PCR. Jejunal lactase activity was lower and lactose concentration was greater in the jejunum and colon in the FO group compared with the SM group (P < 0.05). In the stomach, FO-fed pigs had a lower copy number of 16S rRNA transcripts for allanalyzed bacterial groups (P < 0.05) except for the Escherichia/ Hafnia/ Shigella group. In the jejunum, 16S rRNA transcripts of lactic acid bacteria and clostridial cluster I were lower (P < 0.05) in FO-fed pigs. In turn, transcript abundance of the Escherichia group and clostridialcluster I was greater in FO-fed pigs in the colon (P < 0.05). In FO-fed piglets, concentrations of d-and l-lactate and total and individual short-chain fatty acids were higher in the colon (P < 0.05). Multivariate redundancy analysis revealed that the concentration of minerals (ash, Ca, Mg, K, Na, Mn, and Zn) were associated with reduced bacterial abundance and activity in the upper gastrointestinal tract, whereas lactose had the most pronounced effect on the colon microbiota. The present study revealed that, apart from lactose, the mineral concentration modifies the microbial communities in the gastrointestinal tract of FO-fed piglets.