Potential probiotic properties and storage stability of bacterial consortium isolation from the chicken intestine (Gallus gallus)

Probiotics have been recognized as a viable alternative to antibiotic growth promoters in poultry production due to their beneficial health effects, including improving the immune system and growth performance. Probiotics must meet the necessary safety criteria for use in poultry and achieve Generally Recognized as Safe (GRAS) status. This study assessed eight bacterial consortiums (BC) isolated from the ileum and cecum chicken regions. They were subjected to withstand the challenging probiotic tests (resistance to antibiotics, pH and temperature, antagonist effects, simulated gastric conditions, and mucus adhesion). Subsequently, they were dried by spray- and freeze-drying to evaluate the product storage stabilities for 30 days. BC5-I and BC7-I isolated from ileum were selected as potential probiotics candidates due to presenting a high Lactobacillales and Enterobacterales and more susceptibility to Gram-positive and Gra-negative antibiotics. Also, these BC presented a high tolerance to temperature (>90%), pH>4 (88-98%), and antagonist effects against E. coli and Salmonella. BC5-I exerted the best and most constant survivor viabilities in the simulated gastric conditions, which satisfactorily adhered to the mucus intestine (2.9-fold times). Freeze-dying was the best method to obtain BC5-I and BC7-I powders, with a survival efficiency of 80.3 and 73.2 % at the beginning of the storage. Through survival storage kinetic data, BC5-I presented the lowest cell death rate (k=0.004 day-1) and prolonged half-life (173.3 days) with a slight decrease in viability (1.5 log CFU/g) at the end of storage. Lactobacillus reuteri (59.8 %) was the predominant bacterial population in freeze-dried BC5-I, followed by L. salivarius (40.1%) and L. jhonsonii (0.03%). Therefore, BC5-I emerges as a promising Lactobacillus-based probiotic candidate suitable for administration in poultry-based experimental studies to assess its potential health benefits. It could enhance the quality and production of chicken meat and eggs.