Microencapsulation protected Lactobacillus viability and its activity in modulating the intestinal microbiota in newly weaned piglets.

Abstract

Lactobacilli are sensitive to heat, which limits their application as probiotics in livestock production. Lactobacillus rhamnosus LB1 was previously shown to reduce enterotoxigenic Escherichia coli (ETEC) and Salmonella infections in pigs. To investigate its potential in the application, the bacterium was microencapsulated and examined for its survival from feed pelleting and long-term storage as well as its function in modulating pig intestinal microbiota. The in vitro studies showed that freshly microencapsulated L. rhamnosus LB1 had viable counts of 9.03 ± 0.049 log10 colony forming units (CFU) /g, of which only 0.06 and 0.87 Log of viable counts were reduced after storage at 4 and 22°C for 427 days. The viable counts of encapsulated L. rhamnosus LB1 were 1.06 and 1.54 Log higher in the pelleted and mash feed, respectively, than the non-encapsulated form stored at 22℃ for 30 days. In the in vivo studies, 80 piglets (weaned at 21 days of age) were allocated to five dietary treatments for a 10-day growth trial. The dietary treatments were the basal diet (CTL) and basal diet combined with either non-encapsulated LB1 (NEP), encapsulated LB1 (EP), bovine colostrum (BC), or a combination of encapsulated LB1 and bovine colostrum (EP-BC). The results demonstrated that weaning depressed feed intake and reduced growth rates in pigs of all the treatments during 21-25 days of age; however, the body weight gain was improved during 25-31 days of age in all groups with the numerically highest increase in the EP-BC-fed pigs during 21-31 days of age. Dietary treatments with EP, particularly in combination with BC, modulated pig intestinal microbiota, including an increase in Lactobacillus relative abundance. These results suggest that microencapsulation can protect L. rhamnosus LB1 against cell damage from a high temperature during processing and storage and there are possible complementary effects between EP and BC.