Antimicrobial Properties of Colostrum and Milk Furkan Eker, Emir Akdaşçi, Hatice Duman, Yalçın Mert Yalçıntaş, Ahmet Alperen Canbolat, Arda Erkan Kalkan, Sercan Karav, and Dunja Šamec Abstract: The increasing number of antibiotic resistance genes is putting pressure on the ecosystem and harming human health. Consumers are becoming cautious about chemical preservatives. Colostrum and milk are excellent sources of antibacterial components that help strengthen the immunity of offspring and accelerate the maturation of the immune system. These important defenses, such as lactoferrin, lysozyme, immunoglobulins, and oligosaccharides, can be studied as biotherapeutic agents for the prevention and treatment of infections caused by microbes. Each component has different mechanisms and interactions in various places. The compound's mechanisms of action determine where the antibacterial activity appears. The activation of the antibacterial activity of milk and colostrum compounds can start in the infant's mouth during lactation and continue in the gastrointestinal regions. These antibacterial properties have potential for therapeutic use. Additional research on the mechanisms of action and potential complexes is needed to discover new perspectives and methods for treating bacterial infections. Keywords: milk; colostrum; immunity; bioactive components; antibacterial activity Colostrum, the first milk secreted by mammals in the first 48 hours of lactation, is a key component for neonatal growth, development, and immune defense. It contains high concentrations of immune-related molecules and growth factors, such as immunoglobulins, lactoferrin, oligosaccharides, and epidermal growth factor. It also has a higher concentration of lipids, proteins, minerals, and vitamins compared to mature milk. The composition and quality of colostrum can be influenced by various factors such as environment, breed, individual characteristics, milking time, and diseases. Milk and colostrum contain various antibacterial components, including lactoferrin, lysozyme, immunoglobulins, and oligosaccharides. These components have different mechanisms of action and can be used as biotherapeutic agents for the prevention and treatment of infections caused by microbes. Lactoferrin is a multifunctional glycoprotein that binds iron and has antibacterial, antiviral, and antifungal properties. Lysozyme is an antibacterial protein that hydrolyzes bacterial cell walls. Immunoglobulins are glycoproteins that bind to antigens on viruses and bacteria. Oligosaccharides are carbohydrates that serve as prebiotics and help in the development of the gut microbiome. The antibacterial properties of milk and colostrum have potential for therapeutic use. Research has shown that lactoferrin, lyAntimicrobial Properties of Colostrum and Milk Furkan Eker, Emir Akdaşçi, Hatice Duman, Yalçın Mert Yalçıntaş, Ahmet Alperen Canbolat, Arda Erkan Kalkan, Sercan Karav, and Dunja Šamec Abstract: The increasing number of antibiotic resistance genes is putting pressure on the ecosystem and harming human health. Consumers are becoming cautious about chemical preservatives. Colostrum and milk are excellent sources of antibacterial components that help strengthen the immunity of offspring and accelerate the maturation of the immune system. These important defenses, such as lactoferrin, lysozyme, immunoglobulins, and oligosaccharides, can be studied as biotherapeutic agents for the prevention and treatment of infections caused by microbes. Each component has different mechanisms and interactions in various places. The compound's mechanisms of action determine where the antibacterial activity appears. The activation of the antibacterial activity of milk and colostrum compounds can start in the infant's mouth during lactation and continue in the gastrointestinal regions. These antibacterial properties have potential for therapeutic use. Additional research on the mechanisms of action and potential complexes is needed to discover new perspectives and methods for treating bacterial infections. Keywords: milk; colostrum; immunity; bioactive components; antibacterial activity Colostrum, the first milk secreted by mammals in the first 48 hours of lactation, is a key component for neonatal growth, development, and immune defense. It contains high concentrations of immune-related molecules and growth factors, such as immunoglobulins, lactoferrin, oligosaccharides, and epidermal growth factor. It also has a higher concentration of lipids, proteins, minerals, and vitamins compared to mature milk. The composition and quality of colostrum can be influenced by various factors such as environment, breed, individual characteristics, milking time, and diseases. Milk and colostrum contain various antibacterial components, including lactoferrin, lysozyme, immunoglobulins, and oligosaccharides. These components have different mechanisms of action and can be used as biotherapeutic agents for the prevention and treatment of infections caused by microbes. Lactoferrin is a multifunctional glycoprotein that binds iron and has antibacterial, antiviral, and antifungal properties. Lysozyme is an antibacterial protein that hydrolyzes bacterial cell walls. Immunoglobulins are glycoproteins that bind to antigens on viruses and bacteria. Oligosaccharides are carbohydrates that serve as prebiotics and help in the development of the gut microbiome. The antibacterial properties of milk and colostrum have potential for therapeutic use. Research has shown that lactoferrin, ly