Abstract:

As the core probiotic species in the genus Lactobacillus, Lactobacillus acidophilus exhibits significant application potential in the context of the growing demand for antibiotic substitutes in livestock and poultry breeding, due to its unique characteristics such as acid tolerance, bile salt resistance, and lactic acid production. This article aims to systematically review the biological characteristics, physiological functions, and application status of Lactobacillus acidophilus in livestock and poultry production, clarify its application bottlenecks, and prospect future research directions, so as to provide theoretical support for its widespread adoption. Studies show that Lactobacillus acidophilus can improve the intestinal health of livestock and poultry by competitively excluding pathogenic bacteria and regulating the structure of intestinal microbiota; it can enhance the utilization rate of feed nutrients and promote the growth of livestock and poultry by secreting various digestive enzymes and optimizing the intestinal morphological structure; it can balance the pro-inflammatory and anti-inflammatory responses of the body and enhance immunity by regulating the activation of immune cells and the secretion of cytokines. In livestock and poultry production, it can be used as a feed additive to improve meat and egg quality and reduce the incidence of diarrhea, as a fermentation strain to degrade anti-nutritional factors and enhance the nutritional value of plant-based feeds, and also as an oral vaccine carrier or adjuvant to stimulate mucosal immunity and reduce breeding costs. At present, Lactobacillus acidophilus faces challenges such as difficulty in maintaining activity during processing, inconsistent dosage standards, and incomplete clarification of its mechanism of action. In the future, research should focus on the breeding of heat-resistant and processing-tolerant strains, determining optimal addition doses, elucidating molecular mechanisms of action, and establishing unified evaluation standards, so as to further release its application potential in green livestock and poultry production and contribute to the sustainable development of the animal husbandry industry.

Key words: Lactobacillus acidophilus, intestinal microbiota, feed fermentation, vaccine carrier, vaccine adjuvant