While most HIV-infected patients can now achieve nearly complete viral suppression on currently available HIV medications, they still have at least a 10-year shorter life expectancy than the general population and are at higher risk for diseases associated with accelerated aging including cardiovascular disease and non-AIDS-defining cancers. Persistent inflammation and immune activation are believed to drive this increased risk. Despite suppression of viral replication in peripheral blood by effective HIV medications, HIV may continue to be expressed at low levels by T cells in the lining of the gut and may also result in translocation of bacterial products across the lining of the gut, driving persistent inflammation. We believe that decreasing inflammation directly in the gut may decrease both of these potential causes of chronic inflammation, potentially resulting in an immunologic benefit. Mesalamine is an oral anti-inflammatory drug used to treat patients with inflammatory bowel disease, acts locally on the gut tissue to decrease inflammation, and is associated with very few side effects. If mesalamine therapy reduces immune activation and inflammation in our study, it would prompt larger studies to see if mesalamine decreases clinical outcomes like cardiovascular disease, cancer, and mortality in this setting.