Glycosylation and sugar variations in tyrosol yield promising prebiotic-like effects

Phenolics are common food constituents, and glycosylation enhances their physicochemical properties and biological activities. This study evaluated the prebiotic-like properties of tyrosol and its glycosides, including natural tyrosol β-glucoside (salidroside) and artificially synthesized tyrosol β-galactoside, in C57BL/6J mice. Both glycosides exhibited enhanced effects on probiotics compared to tyrosol. Salidroside stimulated Lactobacillus growth, while tyrosol β-galactoside notably promoted Bifidobacteria proliferation. Akkermansia, a next-generation probiotic, was suppressed by tyrosol but increased by tyrosol β-galactoside. Additionally, the β-galactoside promoted the proliferation of mucus-degrading gut commensals and exhibited the strongest inhibition on certain disease-related genera. Moreover, metabolomic patterns varied between the tyrosol and glycoside groups, particularly in isoflavonoid biosynthesis, with isoflavonoids enriched in the glycoside groups. Glycosylation of tyrosol and variations in its sugar units led to differences in the specificity and abundance of gut bacteria and metabolites. Given its superior prebiotic functions, tyrosol β-galactoside holds potential as a novel food additive.