Probiotic potential of Lactobacilli and Bifidobacteria found in breast milk in Gabon: Isolation, Identification, Antibacterial activity and Perspective for Antibiotherapy

Breast milk is considered the optimal source of nutrition for infants due to its rich bioactive components, including probiotic lactic acid bacteria. These bacteria contribute to gut microbiota balance and prevent the colonization of pathogenic microorganisms. This study aimed to evaluate the probiotic potential of lactic acid bacteria isolated from breast milk in Gabon, with a focus on their antibacterial properties and possible applications in antibiotic therapy. Thirty-four breast milk samples, including colostrum, transitional, and mature milk, were collected from lactating women in Gabon. The bacterial strains were isolated and identified using biochemical and molecular techniques. Their antibiotic susceptibility was assessed using the diffusion method. The probiotic potential of the strains was explored through their ability to survive in simulated gastric and intestinal conditions, growth under varying temperatures, and antibacterial activity against clinically relevant pathogens such as Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli (ATCC 25922). A total of 49 bacterial strains were isolated, with Lactobacillus acidophilus being the most prevalent species across all milk types. The strains exhibited significant resistance to acidic and bile conditions, indicating their capacity to colonize the gut effectively. Additionally, they demonstrated strong antibacterial activity, highlighting their potential role in controlling gastrointestinal infections. The presence of such probiotic strains in Gabonese breast milk underscores the importance of breastfeeding in infant health, particularly in low-income populations where access to medical care is limited. These findings suggest that lactic acid bacteria from breast milk could serve as a natural source of probiotics with antimicrobial properties. Future research should focus on characterizing their bioactive compounds and exploring their application in probiotic supplements or therapeutic formulations for combating bacterial infections.