Fermenting soybeans with Bacillus licheniformis potentiates their capacity to improve cognitive function and glucose homeostaisis in diabetic rats with experimental Alzheimer's type dementia.

Purpose: Brain insulin resistance is related to both diabetes and Alzheimer's disease. We investigated whether both chungkookjangs, soybeans fermented in a traditional method (TFC) and with Bacillus lichenifomis (SFC), can protect against cognitive dysfunction and glucose dysregulation in rats with Alzheimer's disease and type 2 diabetes.

Methods: Partial pancreatectomy (Px) and ICV β-amyloid (25-35) infusion into the CA1 region were fed either control diet (AD-CON), 10% cooked soybeans (CSB), 10% TFC, or 10% SFC in a high fat diet for 8 weeks.

Soybean fermentation with Bacillus licheniformis increases insulin sensitizing and insulinotropic activity.

Traditionally fermented soybeans (chungkookjang; TFC) may have potent anti-diabetic activity, depending on the ambient microorganisms and conditions. We hypothesized that one of the major Bacillus species in TFC contributes to the anti-diabetic activity and could be used to standardize a highly functional TFC. We tested the hypothesis by using cell-based studies to evaluate insulin sensitizing and insulinotropic action of chungkookjangs fermented with various Bacillus spp.