Multiple Probiotic Lactic Acid Bacteria with Marked Cholesterol-Lowering Effects Were Discovered in Equine Colostrum

Xinjiang ranks among the key domestication origins of horses. Local nomadic ethnic groups have a long-standing tradition of consuming equine dairy products, which endows mare-derived dairy matrices with abundant, distinctive and scarce probiotic resources. Equine colostrum is rich in immunoglobulins and growth factors; nevertheless, its pharmacological activities and micro-ecological composition remain poorly characterized. This study aimed to isolate and screen native strains with cholesterol-lowering potential from Xinjiang equine colostrum and conduct a preliminary investigation into their underlying mechanisms. Following isolation and taxonomic identification, one strain of Lactobacillus helveticus, four strains of Lactiplantibacillus plantarum, and two yeast strains including Pichia fermentans and Pichia membranifaciens were obtained. All the aforementioned isolates are indigenous microorganisms naturally inhabiting mare colostrum. In vitro assays demonstrated bile salt hydrolase activity and cholesterol clearance rates ranging from 45.07% to 87.14%, with composite probiotic formulations exhibiting superior efficacy. In vivo results demonstrated that the combination formulation significantly reduced serum levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol (p < 0.05), alleviated hepatic lipid deposition, and regulated gut microbiota composition-notably by enhancing the abundance of beneficial bacteria. It also increased fecal short-chain fatty acids and decreased bile acid levels. These findings demonstrate that the native strains isolated from mare colostrum possess desirable probiotic properties and lipid-lowering bioactivities. Their unique source and natural combinatorial characteristics provide candidate-strain resources for the development of novel functional foods and nutritional supplements.