Dietary magnesium alleviates experimental murine colitis through upregulation of the transient receptor potential melastatin 6 channel

Background: Magnesium (Mg) is essential for human health and is absorbed mainly in the intestine. In view of the likely occurrence of an Mg deficit in inflammatory bowel disease (IBD) and the documented role of Mg in modulating inflammation, the present study addresses whether Mg availability can affect the onset and progression of intestinal inflammation. Methods: To study the correlation between Mg status and disease activity, we measured magnesemia by atomic absorption spectroscopy in a cohort of IBD patients. The effects of dietary Mg modulation were assessed in a murine model of dextran sodium sulfate (DSS)-induced colitis by monitoring magnesemia, weight, fecal occult blood, diarrhea, colon length, and histology. Expression of the transient receptor potential melastatin (TRPM) 6 channel was assessed by real-time reverse transcription polymerase chain reaction and immunohistochemistry in murine colon tissues. The effect of Mg on epithelial barrier formation/repair was evaluated in human colon cell lines. Results: Inflammatory bowel disease patients presented with a substantial Mg deficit, and serum Mg levels were inversely correlated with disease activity. In mice, an Mg-deficient diet caused hypomagnesemia and aggravated DSS-induced colitis. Colitis severely compromised intestinal Mg 2+ absorption due to mucosal damage and reduction in TRPM6 expression, but Mg supplementation resulted in better restoration of mucosal integrity and channel expression. Conclusions: Our results highlight the importance of evaluating and correcting magnesemia in IBD patients. The murine model suggests that Mg supplementation may represent a safe and cost-effective strategy to reduce inflammation and restore normal mucosal function.