Microbial analysis of lactic acid bacteria in homemade fermented milk products

Background: Fermented milk has long been part of human diets, relying on natural fermentation by Indigenous microbes, especially lactic acid bacteria (LAB), which contribute to flavour, preservation, and probiotic benefits. However, the microbial makeup of homemade varieties, particularly from less-studied regions, is poorly understood. Methods: The research looked at 120 samples of fermented milk prepared at home from five different rural regions in Babylon Province. The lactic acid bacteria (LAB) were detected by morphological, biochemical, and molecular techniques, such as 16S rRNA gene sequencing and phylogenetic analysis with MEGA X. Isolation of the bacteria was done using MRS agar. To further understand the patterns of resistance, antibiotic susceptibility testing was also performed. Results: LAB counts varied across regions, with the highest in Area C (7.9 × 10⁸ CFU/mL). Out of 120 isolates, 46 were identified as Lactobacillus species, some with probiotic potential based on phylogenetic analysis. However, many strains showed multidrug resistance (MDR), particularly to β-lactam and macrolide antibiotics. Conclusion: This study reveals significant microbial diversity in homemade fermented milk, highlighting the importance of preserving traditional fermentation methods. It also underscores the need to monitor MDR lactic acid bacteria (LAB) due to their potential health risks and role in spreading antibiotic resistance.