Evaluation of the Lactobacillus gasseri K7 and LF221 strains in weaned piglets for their possible probiotic use and their detection in the faeces

Abstract

Lactobacillus gasseri LF221 and K7 are human isolates that were recognised in previous studies as potential probiotics. In the present study, the detection of LF221 or K7 strains in the faeces as well as their effects on the faecal coliform and lactobacilli counts and on the production parameters were studied in 18 weaned piglets. The animals were divided into three groups: an untreated control group and two groups dosed for 14 days, Lb. gasseri K7 or LF221. The experimental period lasted 25 days. For the discrimination among strains LF221, K7 and other faecal microflora, a combined approach that included culturing on selective media, testing of antimicrobial activity and random amplified polymorphic DNA (RAPD) analysis was used. The administration of a single probiotic strain (a daily dose of 5 × 1010 cfu per piglet) did not significantly influence the viable counts of the coliforms (P > 0.05). A significantly higher number of lactobacilli in comparison with the control group was found in the K7 group after 15 days of probiotic bacteria administration (P = 0.02) but not in the LF221 group. The probiotic treatment did not have a significant influence on feed intake (P > 0.05) and weight gain (P > 0.05). The feed conversion efficiency in the K7 treated group during the whole period was significantly more favourable (P < 0.05) than in the non-treated control group (1.51 and 1.87, respectively). All the piglets remained healthy and no case of diarrhoea was observed. The LF221 and K7 strains survived the passage through the intestines and were successfully detected in the faeces. The colonies identical to the LF221 and K7 strains were isolated only from the faeces of animals fed with the LF221 or K7 strain, respectively.