Comparative effectiveness of probiotic-based formulations on cecal microbiota modulation in broilers

Abstract

The potential of probiotics to manipulate the intestinal microbial ecosystem toward commensal bacteria growth offers great hope for enhancing health and performance in poultry. This study aimed to evaluate the efficacy of five probiotic-based formulations in modulating cecal microbiota in broilers at 21 and 42 days of age. Probiotics investigated included a synbiotic (SYNBIO), a yeast-based probiotic (YEAST), and three single-strain formulations of spore-forming Bacillus amyloliquefaciens (SINGLE1), B. subtilis (SINGLE2) and B. licheniformis (SINGLE3). Metagenomics analyses showed that the cecal microbiota of SINGLE, YEAST, and MULTI supplemented birds had low diversity compared to the control diet without probiotics (CON) at 21d. At the same age, birds fed SYNBIO had a high population of Lactobacillus salivarus and Lachnospiraceae, which was reflected in a singular microbial community illustrated by beta-diversity analyses. By 42d, there were no differences in alpha or beta-diversity in the microbiota of probiotic-treated broilers compared to CON. Birds treated with SINGLE2 had a lower abundance of lactic acid bacteria, while a higher (p<0.05) population of unidentified Lachnospiraceae and Ruminococcaceae. Although the investigated probiotic formulations shared similar taxonomy, modulation of microbiota was not a core outcome for all probiotic-treated broilers indicating the success of microbiota-based intervention may ultimately be dependent on probiotic mixture and broilers age.