Interpretive Summary: Effects of Lactobacillus reuteri LR1 on the growth performance, intestinal morphology, and intestinal barrier function in weaned pigs.
By: Surely Wallace
In a June 2018 article published in the Journal of Animal Science, researchers investigated the effects of probiotic supplementation on intestinal barrier function and morphology, immune response, and the growth performance of weaned pigs. The probiotic strain (Lactobacillus reuteri LR1) used in this study had been previously isolated from healthy weaned pigs.
The authors note that diarrhea in pigs post-weaning is problematic to growth performance. Poor intestinal barrier integrity and inflammation post-weaning are thought to be contributory. Antibiotic supplementation is typically provided to remedy these issues but is not necessarily ideal in the context of antibiotic resistance and public safety. Furthermore, olaquindox (an antimicrobial growth promoter) has been banned in both the EU and in China. The authors therefore study probiotics as a potential alternative to antibiotics in weaned pigs, as this strain has shown good potential in vitro, but has not yet been studied in vivo.
Weaned pigs aged 21 days (n=144) of similar body weight were separated into one control and two treatment groups. Each treatment consisted of 8 replicate pens housing 6 pigs per pen. Treatment diets included: (1) control diet (CON), (2) control diet with added olaquindx and aureomycin (OA), and (3) control diet supplemented with L. reuteri LR1 (5x1010 cfu/kg) (LR1), ad lib. The study period lasted a total of 14 days. Small intestinal samples were collected from one randomly selected euthanized pig per replicate pen to examine intestinal morphology and determine gene activity, cytokines, and antimicrobial peptides.
Results indicated LR1 pigs had increased final body weight and ADG compared with CON pigs. There was no significant difference in G:F ratio between CON, OA and LR1 pigs. Height of ileal villi and crypt depth ratio was increased in LR1 compared to CON and OA pigs. Of five cytokines studied, TGF-β ad IL-22 production was higher in the ileal tissue in LR1 sampled pigs, which suggests promotion of intestinal barrier integrity. The LR1 pigs also had increased ileal mucosal tight junction protein expression. The OA treated pigs had less secretory IgA and other antimicrobial peptides in jejunum compared to CON pigs. For LR1 pigs, sIgA was same or increased compared to CON.
The authors note that these results suggest that L. reuteri LR1 supplemented to the feed of weaned pigs may have the potential to replace antibiotics. Not only does this probiotic appear to promote growth performance above CON pigs, but it also increased the production of antimicrobial peptides and preserved intestinal integrity, which may potentially protect against pathogens and post-weaning diarrhea. More studies to look at these specific effects of probiotics on weaned pigs using different probiotics, combinations of several probiotics, probiotics with prebiotics, or mechanism of protective action would be useful to better understand their potential usefulness to promote growth and prevent post-weaning diarrhea in the swine industry.
To view the full article, “Effects of Lactobacillus reuteri LR1 on the growth performance, intestinal morphology, and intestinal barrier function in weaned pigs,” visit the Journal of Animal Science.