Screening and Probiotic Characterization of Lactobacillus acidophilus CCNH655 and Its Potential Role in Regulating Glucose and Lipid metabolism

Objective: This study aimed to isolate and screen probiotic strains with excellent probiotic properties and metabolic regulatory functions (hypoglycemic and hypocholesterolemic activities) from fermented camel milk in Xinjiang. Methods: Firstly, lactic acid bacteria were isolated and purified from Xinjiang fermented camel milk using traditional microbial isolation techniques. Their potential probiotic properties were systematically evaluated via assays of simulated artificial gastric juice tolerance, bile salt tolerance, auto-aggregation ability, and hydrophobicity. Furthermore, the in vitro hypoglycemic potential was assessed using α-glucosidase inhibition rate and α-amylase inhibition rate as core indicators, while the in vitro hypocholesterolemic efficacy was evaluated based on key parameters including glycine/taurine bile salt hydrolase activity and cholesterol degradation rate. Finally, the antibacterial ability and biological safety of the candidate strain was comprehensively evaluated through antibacterial spectrum determination, hemolysis test, and antibiotic sensitivity test. Results: A total of multiple lactic acid bacteria strains were successfully isolated from the fermented camel milk. After primary screening, 10 candidate strains with strong tolerance to simulated artificial gastric juice (pH3.0) and bile salts (0.2%) were obtained, among which 6 strains exhibited excellent in vitro adhesion ability. Through secondary screening, one Lactobacillus acidophilus strain (designated CCNH655) was ultimately selected. This strain simultaneously displayed superior hypoglycemic activity (as indicated by α-glucosidase inhibition rate 67.19%±5.38% and α-amylase inhibition rate 86.75%±4.34%) and hypocholesterolemic efficacy (reflected by glycine bile salt hydrolase activity 3.89±0.35 U/mL, taurine bile salt hydrolase activity 6.91±0.48 U/mL, and cholesterol degradation rate 79.39%±4.76%) functions. Additionally, it showed a relatively broad antibacterial spectrum, no hemolytic activity, and sensitivity to 9 antibiotics, thus meeting the safety evaluation standards for probiotics. Conclusion: L. acidophilus CCNH655 possesses excellent probiotic properties, significant metabolic regulatory functions, and favorable biological safety. It provides an important strain resource and scientific support for the development of novel functional probiotic products and fermented dairy products targeting the improvement of glucose and lipid metabolism.