Orally administered Lactobacillus casei exhibited several probiotic properties in artificially suckling rabbits

Abstract

Objective: <i>Lactobacilli</i> in rabbit intestine is rare and its function in rabbit gut health is not fully understood. The present study aimed to evaluate <i>in vivo</i> the probiotic potential of <i>Lactobacillus casei</i> for suckling rabbits.Methods: Two healthy 5-day-old suckling rabbits with similar weights from each of 12 New Zealand White litters were selected and disturbed to control group and treatment group. All rabbits were artificially fed. The treatment group had been supplemented with live <i>Lactobacillus casei</i> in the milk from the beginning of the trial to 13 days of age. At 15 days of age, healthy paired rabbits were slaughtered to collect intestinal samples.Results: i) Oral administration of Lactobacillus casei significantly increased the proportion of <i>Lactobacilli</i> in the total intestinal bacteria (p<0.01) and obviously reduced that of <i>Escherichia-Shigella</i> (p<0.01); ii) treatment increased the length of vermiform appendix (p<0.05); iii) a higher percentage of degranulated paneth cells was observed in the duodenum and jejunum when rabbits administered with Lactobacillus casei (p<0.01); and iv) the expression of tolllike receptor 9, lysozyme (<i>LYZ</i>), and defensin-7-like (<i>DEFEN</i>) in the duodenum and jejunum was stimulated by supplemented Lactobacillus casei (p<0.05).Conclusion: Orally administered Lactobacillus casei could increase the abundance of intestinal <i>Lactobacilli</i>, decrease the relative abundance of intestinal <i>Escherichia-Shigella</i>, promote the growth of appendix vermiform, stimulate the degranulation of paneth cells and induce the expression of <i>DEFEN</i> and <i>LYS</i>. The results of the present study implied that <i>Lactobacillus casei</i> exhibited probiotic potential for suckling rabbits.