Exopolysaccharides get a lot of attention because they can improve the host immune system. Exopolysaccharide is a polysaccharide that is produced and secreted from microbes outside the cell, usually found on the outside of the bacterial structure. The Lactobacillus casei group from human breast milk is thought to have the ability to produce exopolysaccharides. The purpose of the study was to examine the exopolysaccharide of the L. casei group that was isolated from breast milk. The methods used include the gravimetric, the phenol-sulfuric acid and the Fourier Transform Infra-Red (FTIR). The results showed that the L. casei group could produce exopolysaccharides, and had high exopolysaccharide total sugar content. Lactobacillus paracasei had the highest exopolysaccharide and total sugar content of 3660 mg/L and 80.6%, respectively. The FTIR results of the L. casei group exopolysaccharides showed the presence of hydroxyl functional groups O-H (3425.76-3295.98 cm-1), methyl C-H (2930.86-2856.70 cm-1), carbonyl C=O (1660.11-1647.27 cm-1), C-H (1456.16-1373.44 cm-1) and C-O-C ether (1071.08-1056.82 cm-1) which are specific characters of exopolysaccharides. Since the FTIR profile demonstrates that the L. casei group can produce exopolysaccharides, it has greater potential as a a probiotic.

The lactic acid bacteria (LAB) isolated from human breast milk is known as probiotics and comprises numerous health benefits. This study aims to select and determine the species name of LAB based on the 16S rRNA gene, which has the potential to be the best indigenous probiotic. The method used included analysis of LAB resistance at acidic pH 2.0 and bile salts (0.5 %), antimicrobial activity against pathogenic microorganisms, and determining the autoaggregation properties. LAB isolates with the best ability in the analysis were then identified using a partial sequence of the 16S rRNA gene. The isolation and purification revealed eight LAB isolates with different parameters named as L19A, L19B, L19C, L19D, L19E, L19F, L19G, and L19H. Isolates L19A, L19E, and L19H have good tolerance ability against acid pH and bile salts, compared to others. Meanwhile, the L19H isolate had the strongest antimicrobial activity against pathogenic microorganisms E. coli ATCC 25922, S. aureus ATCC 25923, and C. albicans ATCC 11778, while the L19A had the highest hydrophobicity, autoaggregation, and coaggregation ability. Based on the partial sequence analysis of the 16S rRNA gene, the L19A, L19E, and L19H have similar values with L. casei, L. rhamnosus, and L. paracasei, respectively. These isolates belong to the L. casei group (LCG) from human breast milk, which can be used as an indigenic probiotic.