Bifidobacterium strains as potential probiotics for poultry: Early contributions to broiler development

Abstract

Bifidobacteria are widely recognized for their contributions to host health and have extensive applications in human nutrition. However, their use in animal production remains limited, largely because many available strains originate from extra-intestinal habitats and lack adaptation to the avian gastrointestinal niche. An effective probiotic for poultry must tolerate the physicochemical conditions of the intestinal tract, lack virulence or other harmful traits, support nutrient utilization through digestive activities, and modulate the immune system without compromising normal growth. These requirements underscore the need to identify avian-adapted Bifidobacterium strains that exhibit not only in vitro probiotic traits but also early in vivo adaptation. Recently, several bifidobacterial isolates, Bifidobacterium animalis LET 401, B. pseudolongum subsp. globosum LET 402 and LET 403, B. pseudolongum subsp. pseudolongum LET 404, LET 405, LET 407, LET 408, LET 410, and LET 412, B. thermacidophilum LET 406, B. thermophilum LET 411, and B. pullorum LET 415, were obtained from chicks and hens raised under diverse conditions. This study further characterized their relevant traits and assessed their early effects in newly hatched chicks. The isolates displayed affinity for wheat- and peanut-derived lectins, resistance to simulated gastrointestinal digestion, inhibitory activity against pathogenic bacteria, and phytase activity. They also exhibited intrinsic antibiotic resistance or moderate susceptibility profiles consistent with safety expectations for bifidobacteria. A short-term in vivo trial demonstrated that early post-hatch administration of 5 × 108 CFU/mL of selected strains supported normal physiological development and contributed to intestinal phytase activity. Besides, the bacterial supplement did not promote translocation nor adversely affect intestinal morphology, metabolic indicators, or the development of the bursa of Fabricius. Together, these findings indicate that the selected bifidobacteria possess promising characteristics for use as early-life modulators of gut development and immunity in poultry.