Inflammatory bowel disease (IBD) is a chronic condition that afflicts individuals repeatedly and cannot be cured at present, which has seriously affected the quality of life of patients. Minerals Containing Rubidium (MCR) from Guangxi Yuechengling, which Professor Zhao Lichun purified, were explored. Against this backdrop, the present study investigates the efficacy of rubidium salt in ulcerative colitis. Rubidium salt reduced levels of inflammatory markers and improved intestinal barrier function through the Elisa kit, immunohistochemistry, and qPCR. Next, we detected the level of short-chain fatty acid and found that the content of propanoic acid, butyric acid, and n-butyric acid increased after treatment with rubidium salt. We used fecal metagenomics to explore the underlying reasons further and found that rubidium salt significantly adjusted the structure of intestinal flora, increased the abundance of beneficial bacteria such as lactobacillus and bifidobacterium, and inhibited the abundance of harmful bacteria such as Enterobacteriaceae and Escherichia coli. We also learned that rubidium salt directly weakened pathogenic bacteria's infection and survival ability by reducing the expression of virulence factors such as fimH, invA, and hilA and virulence genes such as acrA and ompR. Overall, rubidium salt can reduce harmful bacteria and increase beneficial bacteria. The increased beneficial bacteria help enhance the gut barrier and regulate inflammatory factors by raising the levels of short-chain fatty acids. A strengthened gut barrier further stabilizes microbial homeostasis, ultimately alleviating ulcerative colitis.