SLC9A3 and inflammatory bowel disease: Ion transport is equally vital, as the cKO of NHE3 (Na+/H+ exchanger) disrupts luminal Na+/H+ exchange (43), resulting in an alkaline, sodium-rich luminal environment that fosters pro-inflammatory pathobionts while depleting commensal probiotics (81), thus reducing the Firmicutes/Bacteroidetes ratio and reflecting the dysbiotic profile characteristic of IBD (82).