Evaluation of the prebiotic activity of the commercial galacto-oligosaccharide

Galactooligosaccharides (GOS) are established prebiotics, but their role in stimulating the growth of probiotics and the production of beneficial metabolites, such as exopolysaccharides (EPS), varies based on the chemical structure of GOS mixtures. This study investigated the prebiotic activity of a commercial GOS mixture using batch culture fermentation on probiotic strains, including Lactiplantibacillus plantarum, Lacticaseibacillus casei, Lactobacillus acidophilus (LA۵), and Bifidobacterium lactis (BB۱۲). The prebiotic activity score for all probiotic bacteria was less than ۱, which indicates how selectively commercial GOS fosters the growth of probiotic bacteria over glucose. Among them, L. casei obtained the highest score (p < ۰.۰۵). Moreover, probiotics in the GOS samples synthesized EPS at a yield of ۰.۶-۰.۷ g/L. FTIR analysis of the extracted EPS revealed characteristic polysaccharide absorption bands (۹۰۰-۱۲۰۰ cm¯¹, related to glycosidic bonds). It also identified specific functional groups in the EPS that was synthesized by the Lactobacillus strains in the GOS-fermented samples. These results confirmed the bifidogenic effect of the tested commercial GOS and provided novel evidence that it stimulates the production of potentially beneficial EPS, highlighting a secondary mechanism for its prebiotic activity.

کلیدواژه ها:

Commercial prebiotics ، Exopolysaccharides ، Probiotics ، Bifidobacteria