Prebiotic Potential of Non-digestible Oligosaccharides Isolated from Barnyard Millet (Echinochloa frumentacea ) Grain

It is encouraging to see the growing acceptance of millet among the general public, driven by its numerous health benefits. Various research efforts have focused on the many non-digestible oligosaccharides (NDOs) in millets, given their significant nutraceutical potential. Barnyard millet is a viable candidate for extracting NDOs owing to its superior nutritional value and affordability. In the present study, crude oligosaccharides were extracted from barnyard millet under optimized conditions: 80% aqueous ethanol (v/v) at a 1:5 sample-to-solvent ratio for 1 h at 60 {degrees}C, yielding 3.61{+/-}0.24%. Extracted oligosaccharides were further purified through adsorption chromatography and dialyzed through dialysis membranes (500 Da). Several significant peaks at m/z values of 527, 689, 852, 1014, and 1338 were detected in the MALDI-TOF mass spectrum, indicating that barnyard millet oligosaccharides (BMOs) comprise various oligosaccharides with degrees of polymerization (DP) from 3 to 8. BMOs were treated with digestive enzymes (porcine pancreatic and salivary -amylase) and an artificial acidic solution, and results showed that approximately 91% of BMOs were not digested. The positive prebiotic scores and the generation of lactic and short-chain fatty acids (SCFAs) upon fermentation by various probiotic strains indicate the prebiotic potential of BMOs. In this study, the results also showed that the presence of BMOs increased auto-aggregation of lactobacilli and enhanced the adhesion of probiotics to HCT116 cells. Our findings indicate that, with its nutritional benefits, barnyard millet may serve as a viable reservoir of beneficial carbohydrates, including NDOs. HighlightsO_LIExtraction of BMOs under optimized parameters. C_LIO_LIPartial purification of BMOs through charcoal column chromatography and dialysis. C_LIO_LIA positive prebiotic activity score conferred the prebiotic potential of BMOs. C_LIO_LIProduction of short-chain fatty acids by fermentation of BMOs. C_LIO_LIBMOs increased the auto-aggregation percentage of different probiotics. C_LI