Can Magnesium help with gut health?

Magnesium is involved in muscle relaxation and nerve signaling, which theoretically supports bowel motility. Some observational studies link low magnesium levels with constipation, but evidence for direct gut health improvement through supplementation is weak. Mechanistically, magnesium may influence digestive enzymes and gut microbiota composition, but robust clinical trials are lacking. For IBS or IBD, there is insufficient evidence for a therapeutic benefit. High doses of certain forms (e.g., magnesium citrate) have a laxative effect, which can temporarily relieve constipation but is not a long-term solution. Individual tolerance varies. A blood test for magnesium deficiency (e.g., via MyBody-X) may be useful before supplementing. Overall, the evidence is 'mechanistic' or 'unclear' – marketing claims often overstate the effect.