Evaluation of prebiotic potential and selective utilization of isomalto-oligosaccharides by Lactobacillus strains: an...

Isomalto-oligosaccharides (IMOs) having degree of polymerization (DP) that ranges from 2 to 9 was produced through whole-cell biotransformation using maltose and Debaryomyces hansenii strain MCC 0202, possessing α-glucosidase with transglucosidase activity. By selective fermentation and glucose removal using Saccharomyces cerevisiae MCC 0203 for 2 h, total IMOs content of 90% was achieved which was confirmed via HPAEC-PAD analysis. LC-MS/MS was applied to analyse the molecular mass and DP of IMOs. This study evaluated the effectiveness of IMOS as a prebiotic using Lactobacillus strains (L. paracasei and L. plantarum), assessing their growth (2.4 billion CFU/mL) by utilizing IMOs low-purity > 85% and high-purity > 95%. Results revealed IMOs potential as a prebiotic promoting beneficial bacteria like Lactobacillus and inhibiting pathogen like E. coli. High-purity IMOs exhibited higher Prebiotic Index (PI) scores (1.01 for L. plantarum) compared to commercial IMOs and FOS. IMOs showed resistance to digestive enzymes and acidic conditions (maintaining > 90% purity), stimulated probiotic bacterial growth (up to 17.42 mM short-chain fatty acids production by L. paracasei), and inhibited pathogenic bacteria. This study offers a simple, cost-effective method for producing high-quality IMOs, a promising functional food ingredient.