Where do competitive exclusion cultures (such as probiotic Lactobacillus strains) colonize to protect chicks from pathogenic bacteria?

Competitive exclusion is a critical biological defense mechanism utilized to protect newborn chicks from colonizing pathogens like *Salmonella* and *E. coli*. High-quality probiotics, primarily containing *Lactobacillus* and *Bifidobacterium* strains, are administered to day-old chicks. These beneficial bacteria colonize the mucosal epithelial cells and migrate deep into the crypts of the intestinal villi throughout the duodenum and caeca. By physically adhering to the glycoprotein receptors on the enterocytes, they form a dense biological barrier (biofilm). This prevents pathogenic bacteria from attaching and multiplying—a process known as competitive exclusion. Additionally, they secrete organic lactic acid, lowering the local pH to inhibit pathogens. Farmers can study neonatal immunology in the Poultry Encyclopedia, buy high-potency probiotics and prebiotics on Poultry Plaza, monitor weekly chick prices on Poultry Rates, and list healthy, gut-stabilized flocks on Murghi Mandi.