Beneficial Preventive Effects of Gastric Mucosal Lesion for Soy−Skim Milk Fermented by Lactic Acid Bacteria

Abstract

In this study, Lactobacillus paracasei subsp. paracasei NTU101 and Lactobacillus plantarum NTU 102 were used as starter to ferment soy−skim milk, and the optimal mixing ratio was evaluated. The influence of lactic acid bacteria (LAB)-fermented soy−skim milk on mucosal integrity in a gastric mucosal lesion rat model was also investigated. After 24 h, cell densities of L. paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 fermented in 75% soy milk and 25% milk (optimal condition) were 1.2 × 10⁹ and 2.5 × 10⁹ CFU/mL. After 180 days at 4 °C, the cell densities of the freeze-dried powders of the fermented soy−skim milks were 1 × 10⁹ CFU/g; slight variations in pH and acidity were observed. Pylorus ligation with acidified ethanol treatment was used as the gastric lesion animal model. LAB-fermented soy−skim milk reduced the gastric lesion index and the lipid peroxides (LPO) of gastric mucosa and serum. Administration of the fermented soy−skim milk enhanced superoxide dismutase (SOD) activity and prostaglandin E₂ (PGE₂) synthesis. Therefore, LAB-fermented soy−skim milk at 10⁹ CFU/day protects against gastric injury.