Synbiotic alginate microcapsules incorporating a date seed polysaccharide-stabilized Pickering emulsion improve probiotic gastrointestinal survival and modulate SCFA production, gut microbiota, and fecal metabolome.

内容摘要

This study formulated alginate microbeads incorporating a date seed polysaccharide-stabilized pickering emulsion (Alg:PSE) aimed at enhancing probiotic survival and regulating gut microbiota in a strain-dependent manner. Lacticaseibacillus rhamnosus and Bifidobacterium longum subsp. longum strains were individually encapsulated within alginate beads, alginate with the ultrasound-extracted date seed polysaccharide (UPS), and alginate with the UPS-stabilized pickering emulsion (PSE). Among various compositions evaluated herein, Alg:PSE2 was identified as the best one based on the highest encapsulation efficacy and viability rates of L. rhamnosus (AET3) and B. longum (AET8). In comparison with alginate beads, both AET3 and AET8 resulted in denser, harder, less swellable, and heat-stable matrices with smooth and less porous surfaces. Moreover, both microcapsules could significantly enhance the biological activity of bioaccessible fractions following in vitro digestion in terms of their antioxidant capacity and inhibition against α-amylase and α-glucosidase enzymes. Both AET3 and AET8 could stimulate an earlier response of fermentation within 24 h of fecal fermentation with the notable production of propionic and butyric acids. Notably, such treatment caused distinct alterations in microbial community profile by enriching short-chain fatty acids (SCFAs)-associated genera and eliminating the presence of pathogenic genera like Klebsiella. Unbiased metabolomics analysis using LC-MS illustrated distinctive metabolome profiles associated with the predominance of SCFAs, amino acids, and lipids.