Dual layer alginate-mesoporous silica nanoparticle carriers for improving the in vivo cholesterol-lowering capacity of the potential probiotic Sporobolomyces roseus

Microencapsulation strategies enable us to improve functional and health-promoting capabilities of probiotic (PRO) yeasts. In the present study, predominant yeast isolated from fermented sprouted chickpeas was selected based on its cholesterol-lowering ability (ChLa). Phylogenetic evolutionary analysis led to the identification of Sporobolomyces roseus as the selected isolate. In vivo biosafety of the yeast isolate (YI) was also verified according to the liver enzymes activity and blood biochemistry parameters of the fed mice. Moreover, the YI exhibited proper antimicrobial activities, adhesion abilities and other PRO attributes. Anti-ochratoxigenic activity of the autoclaved cells of the isolate was significantly ( p <0.05) higher than those of the yeast viable cells and its cell-free supernatant according to the HPLC-based analysis. Encapsulation of the isolate in dual layer alginate-mesoporous silica nanoparticles significantly improved its survivability under simulated gastrointestinal conditions compared to the free yeast. Fourier-transform infrared spectroscopy and scanning electron microscopy also approved cross-linking of functional groups in the wall materials and efficient coating of the inner alginate layer with silica. Importantly, double-layer encapsulated yeast showed higher in vivo ChLa than those of the mono-layer encapsulated isolate and the free yeast. Lipid plasma profile of the fed mice with the produced carrier and encapsulated yeasts was also significantly improved in comparison with the free yeast. Histological analysis also verified protective effects of the encapsulated yeast in hypercholesterolemic mice. In addition, the double-layer encapsulated yeast exhibited proper storage stability compared to the free cells.