In this study, we observed
disease progression, changes in the gut microbiota, and interactions among the brain, liver, pancreas, and intestine in a mouse model of
Alzheimer's disease (AD), in addition to attempting to inhibit
disease progression through the dietary supplementation of
L-arginine and
limonoids. Wild-type mice (WC) and AD mice were fed a normal diet (AC), a diet supplemented with
L-arginine and
limonoids (ALA), or a diet containing only
limonoids (AL) for 12-64 weeks. The normal diet-fed WC and AC mice showed a decrease in the diversity of the gut microbiota, with an increase in the Firmicutes/Bacteroidetes ratio, and bacterial translocation. Considerable bacterial translocation to the pancreas and intense
inflammation of the pancreas, liver, brain, and intestinal tissues were observed in the AC mice from alterations in the gut microbiota. The ALA diet or AL diet-fed mice showed increased diversity of the bacterial flora and suppressed oxidative stress and inflammatory responses in hepatocytes and pancreatic cells, bacterial translocation, and neurodegeneration of the brain. These findings suggest that
L-arginine and
limonoids help in maintaining the homeostasis of the gut microbiota, pancreas, liver, brain, and gut in AD mice.