This module covers the clinical foundations of gut health, including gut physiology, the mucosal barrier, Gut-Associated Lymphoid Tissue (GALT), the enteric nervous system, and the role of gut microbiota and metabolites such as short-chain fatty acids. It explores common gastrointestinal conditions including IBS, IBD, SIBO, and GERD, along with their underlying physiological and dietary considerations. The module introduces functional foods, prebiotics, probiotics, postbiotics, fermented foods, and polyphenols as components of individualized gut-health strategies. It also presents a four-week gut restoration framework—Remove, Replace, Re-inoculate, and Repair—while emphasizing assessment of bowel patterns, stress, sleep, dietary triggers, and medication history before developing a personalized nutrition protocol.