The cecal appendix: one more immune component with a function disturbed by post-industrial culture.

Area of Science:

• Immunology
• Evolutionary Biology
• Gastroenterology

Background:

• The cecal appendix has long been associated with immune tissue, suggesting a role in immune function.
• Recent research highlights the appendix as a reservoir for beneficial gut microbiota.
• Understanding gut flora-immune system interactions is key to deciphering appendix function.

Purpose of the Study:

• To review current knowledge on the cecal appendix's function, evolution, and immunological significance.
• To explore the appendix's role as a bacterial safe-house.
• To analyze the impact of societal changes on the appendix's relevance.

Main Methods:

• Literature review of immunological and evolutionary studies.
• Analysis of morphological and phylogenetic data of the appendix.
• Epidemiological data review concerning diarrheal illness and appendicitis.

Main Results:

• The appendix serves as a safe-house for gut bacteria, crucial for recovery from diarrheal illness.
• Evolutionary and morphological evidence supports a significant function for the appendix.
• Its importance is reduced in developed nations due to modern hygiene and medicine.

Conclusions:

• The cecal appendix is a vital immune-related organ in natural environments, particularly against diarrheal diseases.
• Modern lifestyles have lessened the appendix's critical role, potentially increasing susceptibility to conditions like appendicitis.
• The appendix's function is context-dependent, varying with environmental and societal factors.