Therapeutic Potential of Bacillus amyloliquefaciens NPKE6 Fermented Metabolites with Superoxide Dismutase (SOD)-Mediated Antioxidant and Anti-Inflammatory Effects in Liver Injury and Colitis Animal Models

In this study, we evaluated the physiological effects of fermented metabolites derived from puffed grains (z), fermented using Bacillus amyloliquefaciens NPKE6, a strain isolated from Korean water kimchi. In vitro assays showed that NPKE6-FM significantly increased antioxidant enzyme activities (SOD, CAT, GPx) and digestive enzyme activities (α-amylase, protease), suggesting its strong biofunctional potential. To confirm its in vivo efficacy, we established two inflammatory disease models—ulcerative colitis and liver injury—in male C57BL/6 mice. Colitis was induced by oral administration of 1% dextran sodium sulfate (DSS, 1 mL), while liver injury was induced by intraperitoneal injection of acetaminophen (APAP, 300 mg/kg) three times per week for 4 weeks. In disease-induced control groups, elevated serum biomarkers (AST, ALT, ALP) and reduced antioxidant activity were observed. Experimental groups received 10 or 50 mg/kg/day of NPKE6-FM for 4 weeks. Treatment significantly restored antioxidant enzyme levels and reduced inflammatory markers such as TNF-α and IL-6. In the colitis model, NPKE6-FM alleviated DSS-induced tissue damage, evidenced by improved colon length, weight, and histological scores. Gene expression analysis showed downregulation of iNOS and COX-2 in colon tissues and Akt and MCP-1 in liver, indicating molecular anti-inflammatory effects. Although liver histopathology did not show marked improvement, biochemical and gene expression results supported its protective role. In summary, NPKE6-FM demonstrated potent antioxidant and anti-inflammatory activities in vitro and in vivo, indicating its potential as a functional food additive to prevent or alleviate inflammatory conditions such as colitis and liver injury.