Effects of Different Oligosaccharides on Growth of Selected Probiotic Bacterial Strains

Abstract

Objective: To assess if prebiotics at different concentrations can accelerate the growth of selected probiotic bacterial strains. Materials and methods: Enterococcus (E.) faecium NCIMB 10415 E1707 was chosen as it is the most common probiotic strain used for small animals. In addition, E. faecium NCIMB 30183, Bifidobacterium (B.) longum NCIMB 30182 and B. infantis NCIMB 30181 were tested. They were grown in 96-well plates and growth was assessed by optic density at 600 nm, using a bacterial plate reader. The prebiotics used were Fructo-Oligosaccharides (FOS), mannan oligosaccharides (MOS) and Preplex ® (a combination of FOS and gum Arabic available in a commercial synbiotic product for small animals). Initially, addition of inulin was also planned but not achieved due to technical difficulties. The prebiotics were used at 20 mg/ml, 10 mg/ml, 1 mg/ml and 0.1 mg/ml, respectively. Growth rates were calculated, technical and biological repeats averaged and compared between prebiotic treatments for each strain using ANOVA. Results: Growth of E. faecium NCIMB 10415 E1707 was not improved by any additive. E. faecium NCIMB 30183 grew significantly faster with the highest concentration of Preplex ®. Both Bifidobacterium strains showed significant acceleration of growth with Preplex ® and FOS, but only B. infantis showed a dose-effect. Conclusion and clinical significance: Prebiotic additives have to be chosen depending on the probiotic strain. The E. faecium strain most commonly used in small animals was not influenced by any of the prebiotics used, even though commercially available as a synbiotic. The growth of Bifidobacteria was accelerated with commonly used prebiotic oligosaccharides. Interestingly, the addition of gum Arabic seemed to have a stronger effect on growth acceleration than FOS alone. The information gained might have implications for the design and production of pre-and probiotic formulations for small animals in the future.