Final answer:
Gut immunity can be influenced externally by the introduction of probiotics and the use of antibiotics, which impact the gut microbiota and immune responses.
Step-by-step explanation:
Two examples of external influence on gut immunity are:
- The introduction of probiotics, which can modify the intestinal microbiome, influencing the mucosal-associated immune system (MALT), and subsequently enhancing the cellular immune response through activation of macrophages, antigen-specific cytotoxic T-lymphocytes, and release of cytokines.
- Antibiotic use leading to dysbiosis, which can reduce the population of normal gut bacteria, allowing for the overgrowth of antibiotic-resistant bacteria like Clostridium difficile, further impacting the gut immune response and possibly leading to severe gastrointestinal issues.