Unlike immune support supplements, which provide vitamins, minerals, botanicals, or other ingredients marketed around immune function, although immune effects are ingredient-specific and no broad supplement category can guarantee prevention, treatment, or cure of infection, gut health supplements deliver probiotics, prebiotics, fibers, enzymes, or other ingredients aimed at a defined digestive function.
The deciding issue is different mechanisms. For gut health supplements, examine strain identity and viable count; for immune support supplements, examine immune function and nutrient status. Specifications help only when the task has been defined.