Abstract
Simple Summary The emergence of antibiotics resistance is a warning sign to limit antibiotics usage as growth promoters in the poultry industry. Probiotics served as superior candidates for replacing antibiotics in the poultry sector. However, the beneficial functions of probiotics did not reach their targeted outcomes owing to the harsh environment in the poultry gut. In this context, evolution of biotechnological aids offers new avenues for increasing bioavailability and beneficial efficacy of in-feed additives including probiotics. Therefore, encapsulation of Bacillus amyloliquefaciens (B. amyloliquefaciens) into nanocarriers boosted its growth-promoting purposes and consequently modulated the functions of digestive enzymes and kept the microbiota homeostasis towards the beneficial ones. The strengthening capability of B. amyloliquefaciens-loaded nanoparticles for broilers' gut barrier limited Campylobacter jejuni (C. jejuni) colonization and shedding. This superior outcome would in turn interrupt the transmission cycle of C. jejuni through the food chain and consequently protect against its adverse consequences in humans. Probiotics as novel antibiotics' substitutes are verified to provide barriers for hindering the colonization of enteric bacterial pathogens with nutritional benefits. For enhancement of the probiotics' effectiveness, their integration within nanomaterials is a paramount tool to support the progress of new compounds with functional features. Therefore, we addressed the impact of effective delivery of probiotics (Bacillus amyloliquefaciens) loaded nanoparticles (BNPs) on performance and Campylobacter jejuni (C. jejuni) shedding and colonization in poultry. Two hundred Ross broiler chickens were divided into four groups fed various BNP levels: BNPs I, BNPs II, BNPs III, and BNPs-free diets for 35 days. Nanoparticles delivery of probiotics within broiler diets improved growth performance as reflected by higher body weight gain and superior feed conversion ratio, especially in BNPs II- and BNPs III-fed groups. In parallel, the mRNA expression levels of digestive enzymes encoding genes (AMY2a, PNLIP, CELA1, and CCK) achieved their peaks in BNPs III-fed group (1.69, 1.49, 1.33, and 1.29-fold change, respectively) versus the control one. Notably, with increasing the levels of BNPs, the abundance of beneficial microbiota, such as Bifidobacterium and Lactobacillus species, was favored over harmful ones, including Clostridium species and Enterobacteriaceae. Birds fed higher levels of BNPs displayed significant improvement in the expression of barrier functions-linked genes including DEFB1, FABP-2, and MUC-2 alongside substantial reduction in cecal colonization and fecal shedding of C. jejuni. From the aforementioned positive effects of BNPs, we concluded their potential roles as growth promoters and effective preventive aids for C. jejuni infection in poultry.