A comparative study on antidiabetic and anti-inflammatory activities of fermented whey and soy protein isolates and the release of biofunctional peptides: an in vitro and in silico studies.

Abstract

Background: This study aims to evaluate the antidiabetic and anti-inflammatory activities of Lacticaseibacillus rhamnosus (M9) MTCC 25516 during the fermentation of whey and soy protein isolates. It also seeks to characterize protein profiles, identify multifunctional peptides, and assess structural changes using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two-dimensional (2D) gel electrophoresis, Fourier-transform infrared (FTIR) spectroscopy, and confocal laser scanning microscopy (CLSM).

Results: Fermentation with Lacticaseibacillus rhamnosus (M9) significantly enhanced antidiabetic activity, with optimal peptide production at a 25 mL L^-1 inoculation rate for 48 h at 37 °C. Proteolytic activity reduced inflammatory markers (IL-6, TNF-α, IL-1β, NO) in RAW 267.4 cells. SDS-PAGE and 2D gel electrophoresis revealed distinct protein profiles, with 19 and 49 protein spots in whey and soy isolates, respectively. Reverse-phase high-performance liquid chromatography (RP-HPLC) identified multifunctional peptides, and FTIR spectroscopy confirmed structural changes post-fermentation. Confocal microscopy further revealed protein modifications.

Conclusion: Fermentation of whey and soy protein isolates with Lacticaseibacillus rhamnosus (M9) enhances antidiabetic and anti-inflammatory properties. Optimal conditions (25 mL L^-1 inoculation, 48-h incubation) improved peptide production, with analytical techniques confirming structural and functional changes. These findings suggest fermented protein isolates could be valuable in functional foods with health benefits. © 2025 Society of Chemical Industry.