Sprouting alters metabolite and peptide contents in the gastrointestinal digest of soybean and enhances in-vitro anti-inflammatory activity

Sprouting of soybeans can enhance the release of health-beneficial bioactive compounds, especially peptides, and metabolites, while gastrointestinal (GI) digestion alters their biotransformation and bioaccessibility. The present study aimed to evaluate the effect of soybean sprouting and GI digestion in modulating its anti-inflammatory activity. Soybeans were soaked in water overnight (Day 0) and sprouted for two and four days, subjected to simulated GI digestion, and human intestinal epithelial cells (Caco-2) were pretreated (2 h) with soybean sprout digest (SSD: 1000 mu g/mL) before inflammation induction with IL-1 beta. Pre-treatment with Day 4 SSD specifically reduced the secretion of cytokine IL-8 by 19.5%. Sprouting for four days and GI digestion significantly increased the abundance of metabolites, including valine, isoleucine, citrulline, and trigonelline. Furthermore, the abundance of peptides with polar-hydrophilic and charged amino acids was explicitly accumulated in the Day 4 SSD up to 6-fold. These metabolites and peptides are potentially responsible for the observed anti-inflammatory effects.