Abstract
Introduction: The overuse of antibiotics has led to a surge of antibiotic resistant bacteria in recent decades. Animal agriculture has proven to be a significant contributor to this overuse. The investigation of potential alternatives to antibiotics in animal agriculture is thus warranted.
Methods: We conducted a literature review exploring four alternatives for antibiotic use in an animal agricultural setting: phytochemicals, antimicrobial peptides, probiotics, and bacteriophages.
Results: Four different types of antibiotic alternatives were evaluated. The first one is phytochemicals, a broad group consisting of five subtypes: alkaloids, carotenoids, polyphenols, terpenoids, and organosulfur compounds. Many of these display antibacterial properties such as interacting with the cytoplasmic membrane, immunomodulatory activities, inhibiting specific components of DNA replication, and even inactivating specific enzymes vital for the survival of bacteria. All these subtypes displayed various antibacterial properties in animal studies surrounding poultry and livestock. The second alternative is antimicrobial peptides, which have shown to be effective in treating conditions such as post-weaning stress and necrotic enteritis in various animals. The third alternative is probiotics, which have demonstrated both growth promotion and disease prevention properties. One study also concluded that probiotics provide financial benefits to farmers. The fourth antibiotic alternative is bacteriophages, a class of viruses that infect bacteria. Phages have shown disease prevention and growth promotion properties; they also can prevent the transmission of zoonotic diseases.
Discussion: Phytochemicals, antimicrobial peptides, probiotics, and bacteriophages all demonstrate the capability of acting as antibiotic alternatives. Each of these alternatives are unique with their own advantages and disadvantages; hence, the applicability is broad.
Conclusion: Four antibiotic alternatives (phytochemicals, antimicrobial peptides, probiotics, and bacteriophages) were researched for disease prevention and growth promotion properties, inherent functions of antibiotics. The applicability of such options in livestock and poultry is vast. Therefore, given more funding for research studies and policy changes, many of these options can be implemented if not already.