TJP1 and colitis: • SB@TA/Mg2+@CPP decreased the phenotypic alterations of colons and improved the abundance and diversity of GM (increased beneficial bacteria, e.g., Muribaculaceae, and decreased the pathogenic bacteria, e.g., Escherichia-Shigella)It increased tight junction proteins (ZO-1 and occludin), reduced inflammatory parameters, and promoted magnesium adsorption in DSS-induced colitis mice