Stress tolerance, safety, and probiotic traits of cholesterol-decreasing Bifidobacterium BLH1 isolated from Guizhou red sour soup, a traditional Chinese fermented food

Red sour soup, a traditional fermented food native to Guizhou, is characterized by its diverse microbiota, offering significant potential for uncovering beneficial microorganisms, but fewer related studies exist. This study assesses the stress tolerance, safety, and probiotic properties of 26 strains isolated from red sour soup. Employing Li-MUP-modified MRS agar medium and Principal Component Analysis (PCA), the research focuses on identifying outstanding new bifidobacteria strains. The study revealed that one tested strain, identified as Bifidobacterium animalis subsp. lactis BLH1 through 16S rRNA analysis demonstrated remarkable resilience, surviving over 95% in low pH and 5 mg/mL bile salt conditions and a 20% CO2-80% atmosphere air environment, and exhibited non-toxicity and notable probiotic properties. BLH1 outperformed the commercial strain BB12 in nitrite degradation, adhesion, and hydroxyl radical scavenging, achieving a 74.85% efficiency (p < 0.05). Importantly, BLH1 demonstrated a superior cholesterol-lowering capacity, with a reduction rate of 51.62%, surpassing Bifidobacterium animalis, with substantial potential for use in functional foods due to its remarkable bioactivity and health benefits.