A synbiotic made of an autochthonous Enterococcus durans strain and microbial polysaccharides improves broiler chicken health

Abstract

Purpose: The gastrointestinal tract (GI) of organically fed desi chickens fosters a microbiota that can exclude pathogens and be potentially probiotic for improving the gut health of commercial chickens. Methods: A panel of strains were selectively cultured from desi chicken intestine and screened for their antagonism towards specific pathogens. Treating the culture free supernatant (CFS) of such strains with NaOH and proteases gives a picture of the antibacterial compound's biochemistry and determining its minimum inhibitory concentration (MIC) provides a measure of potency. The most strongly antagonistic strains were tested in vitro for surviving the chicken GIT. Safety was examined using mucin degradation, gelatin liquefaction, hemolysis, antibiotic susceptibility and biogenic amine production. An in vivo trial was done on young male Ross chickens to evaluate the performance of a bespoke synbiotic formulation comprising of an Enterococcus durans strain (1x108 CFUg−1) with prebiotics Dextran or Levan (0.1% w/v) and with both and assessing its impact on broiler gut microbiota, body and carcass weight, histopathology of organ tissues, and biochemical markers. Results: A panel of Enterococcus spp. (NPL1315-NPL1334) was obtained and the selected strains (NLP-1319, 20, 24, 27, 34) showed good bile, acid and phenol survival, and cell surface hydrophobicity but not autoaggregation and none of them were deemed unsafe. The synbiotic-fed chickens were significantly heavier, with lowered serum cholesterol, triglycerides and glucose levels and a lesser load of pathogens than the controls. Conclusion: Desi chicken intestine can be a viable source of probiotics with good antagonistic potential capable of replacing antibiotics in poultry feed.

Keywords

• Enterococcus
• Poultry
• Microbial exopolysaccharides
• Antagonism
• Synbiotics