Methylglyoxal (MGO), a potent dietary glycotoxin, serves as a key precursor to Advanced Glycation End products (AGEs), which have been linked to an increased risk of Alzheimer's disease (AD) exacerbation. Recognising the significance of lifestyle modifications, particularly nutritional interventions, in preventing brain deterioration, this study aimed to reveal the potentially harmful effects associated with a high-MGO diet on both brain and gut health.Our findings demonstrated MGO administration adversely affected working memory, inducing neuroinflammation and oxidative stress by modulating the AGE-receptor (RAGE). The hippocampus of MG-treated mice exhibited increased gene and protein expressions of RAGE, with reduced glyoxalase-1 activity, a pivotal enzyme in MGO detoxification. Additionally, increased expression of proinflammatory cytokines and enhanced activities of NADPH-oxidase and catalase were also found in MGO-mice. MGO administration also upregulated the gene and protein expressions of Presenilin-1. In the gut, MGO increased the formation of MGO-glycated proteins, induced pro-inflammatory status, and reduced the expression and delocalization of zonulin-1 and occludin. Changes in intestinal morphology including hyperproliferation of Paneth and goblet cells, and an augmented thickness of the intestinal mucus layer were also observed in MGO-mice. Microbiota composition analysis revealed selective modification induced by MGO, with a reduction in bacteria associated with acetic and butyric acids, and a substantial increase in Lachnospiraceae and Akkermansia genera.These comprehensive findings reveal the intricate impact of dietary-MGO on both brain and gut, suggesting that more in-depth studies will be needed to explore the involvement of the gut-brain-axis in mediating the glycotoxic impact of MGOs in AD exacerbation.