Abstract

Goat milk, a key product of small ruminant farming, harbors a diverse microbiota that may serve as a valuable source of probiotics with health-promoting properties. This study aimed to isolate and characterize probiotic bacteria from raw goat milk collected from traditional goat-rearing systems and evaluate their potential for application in both animal health management and human functional food development. A total of 32 bacterial isolates were screened through in vitro assays for core probiotic attributes, including Gram’s staining, catalase activity, tolerance to gastric acidity (pH 2.0–3.0) and bile salts (0.3%), antimicrobial activity against common enteric pathogens, auto-aggregation potential, and epithelial cell adhesion. Molecular identification using 16S rRNA gene sequencing revealed several promising strains, notably Lactobacillus helveticus, Heyndrickxia coagulans, Bacillus aerolacticus, and Bacillus subtilis. These isolates exhibited strong survival in simulated gastrointestinal conditions and displayed broad-spectrum antimicrobial activity. All selected strains were non-hemolytic, indicating their safety for oral use. The results highlight raw goat milk as a valuable small ruminant-derived reservoir of safe and functionally potent probiotic bacteria. These strains hold promise for development as functional feed additives to support gut health and immunity in small ruminants as well as ingredients in human health-promoting dairy products.

Key words: Goat milk; Probiotic bacteria; Functional foods; Animal health; 16S rRNA sequencing; Antimicrobial activity