Table 5.

Impacts of probiotics, prebiotics, and synbiotics on poultry performance.

Antibiotic alternatives	Type	Application	Treated birds	Mode of action	Effects	References
Probiotics	Bacillus amyloliquefaciens	Applied as 0, 1, 5, 10, and 20 g probiotics/kg feed	Broiler chickens	Improved the immune response of birds	Improved gut health and growth performance	Ahmed et al., 2014
	Saccharomyces cerevisiae	Applied as 0.4, 0.8, 1.2, and 1.6% feed	Layer chickens	Usage of 0.4 or 0.8% Saccharomyces cerevisiae increased the productivity and nutrients utilization via the inhibitory effect of yeast against pathogens	Improved growth performance and improved laying performance	Hassanein and Soliman, 2010
	Streptococcus faecium	Dietary supplementation	Poultry	Showed immunomodulating activity	Improved immunity	Alagawany et al., 2018a
	Propionibacterium acidipropionici	Dietary supplementation	Broiler chickens	Improved gut microbiome and improved gut integrity	Showed better development of gut mucosa	Martínez et al., 2016
	Bacillus licheniformis	Dietary supplementation	Broiler chickens	Increased growth performance, carcass characteristics, meat quality, muscular antioxidant capacity, and meat mineral contents	Prevented necrotic enteritis and enhanced growth performance	Cheng et al., 2017
	Lactobacillus salivarius	Dietary supplementation	Broiler chickens	Improved gut development and increased beneficial microbial community	Improved performance and enhanced gut histomorphology.	Olnood et al., 2015
	Bacillus subtilis	Dietary supplementation	Layer chickens	Increased egg quality, hatchability, and sperm quality of roosters	Increased laying performance and helped the immune system and gut health	Mazanko et al., 2018
	Lactobacillus plantarum, Enterococcus faecalis, Propionibacterium freudenreichii ssp.	Dietary supplementation	Broiler chickens	Improved digestion, absorption, gut barrier function, and gut structure	Improved immunity, and birds’ productivity	Smolovskaya et al., 2023
	Bacillus amyloliquefaciens H57	Dietary supplementation	Broiler chickens	Changed the functional capacity of the cecal microbiota, parallel with vitamin and amino acid synthesis pathways	Increased bird productivity	Bajagai et al., 2023
	Bacteroides caecicola, Bacteroides plebeius, Megasphaera stantonii, Megamonas hypermegale, Megamonas funiformis, Phascolarctobacterium faecium, and Sutterella massiliensis	On first day of life, chicks in the experimental group were orally inoculated with 0.1 mL of gut anaerobes	Broiler chickens	Reduced challenged ciprofloxacin-resistant Escherichia coli colonization in birds’ gut	Provided protection during the essential period of the chicken intestinal microflora development	Papouskova et al., 2023
Prebiotics	Yeast powder	Applied as 1.5–2.0 g/kg feed	Broiler chickens	Increased ileal protein digestibility and pancreatic enzyme activities.	Improved performance and meat yield	Ahiwe et al., 2020
	yeast (Saccharomyces cerevisiae)	Feed	Broiler chickens	Modulated gut microflora	Improved performance	Al-Homidan and Fahmy, 2007
	Saccharomyces cerevisiae	Applied as 4.0 g/kg feed	New Zealand White Rabbits	Increased the total thickness of the mucosa, villus heights, crypt depths, and gland depths	Improved gut health	Seyidoglu and Peker, 2015
	Saccharomyces cerevisiae and Kluyveromyces maxianus	Applied as 1:1 feed	Broiler chickens	Increased the number of Lactobacillus and decreased the number of Escherichia coli in the excreta	Increased body weight gain	Sun and Kim, 2019; Abd El-Hack et al., 2021d
Synbiotics	Galactooligosaccharides) and probiotic Bifidobacterium longum	Oral supplementation	Broiler chickens	Increased the colonization of beneficial bacteria and limited the propagation of pathogens	Increased the count of Bifidobacterium and reduced the count of Campylobacter jejuni	Baffoni et al., 2012
	Galactooligosaccharides and a Bifidobacterium lactis-based probiotic)	Oral supplementation	Broiler chickens	Increased the colonization of beneficial bacteria and limited the propagation of pathogens	Increased the count of Bifidobacterium	Jung et al., 2008
	fructooligosaccharides with Enterococcus faecium	Oral supplementation	Broiler chickens	Increased the colonization of beneficial bacteria and limited the propagation of pathogens	Reduced total coliform counts while increased lactic acid-producing bacterial count	Dibaji et al., 2014