Comparative anatomy and phylogenetic distribution of the mammalian cecal appendix

@article{Smith2009ComparativeAA,
  title={Comparative anatomy and phylogenetic distribution of the mammalian cecal appendix},
  author={Heather F. Smith and Rebecca E. Fisher and Michael L. Everett and A. D. Thomas and R. Randal Bollinger and William Parker},
  journal={Journal of Evolutionary Biology},
  year={2009},
  volume={22}
}
A recently improved understanding of gut immunity has merged with current thinking in biological and medical science, pointing to an apparent function of the mammalian cecal appendix as a safe-house for symbiotic gut microbes, preserving the flora during times of gastrointestinal infection in societies without modern medicine. [] Key Result A comparative anatomical approach reveals three apparent morphotypes of the cecal appendix, as well as appendix-like structures in some species that lack a true cecal…
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The cecal appendix may be viewed as a part of the immune system that, like those immune compartments that cause allergy, is vital to life in a “natural” environment, but which is poorly suited to post‐industrialized societies.
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It is found, through analyses of data on 258 mammalian species, that cecal appendix presence is correlated with increased maximal observed longevity, the first demonstration of a correlation between cecAL appendix presence and life history.
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The first comprehensive view of the microbial composition of the appendix as determined by high-throughput sequencing concludes that the human appendix contains a robust and varied microbiota distinct from the microbiotas in other niches within the human microbiome.
The vermiform appendix: an immunological organ sustaining a microbiome inoculum.
TLDR
A plausible appreciation results of the importance of the importance of multiple immunological aspects of a healthy vermiform appendix and the provision of a commensal biofilm to the gut that repairs a dysbiotic microbiome contributing to balancing intestinal pro- and anti-inflammatory activity for maintaining homeostasis in the gut.
The immunology of the vermiform appendix: a review of the literature
TLDR
The idea of the appendix being a vestigial organ should therefore be discarded, as multiple immunological aspects point towards the appendix as a priming site for ulcerative colitis.
Phylogeny and herbivory are related to avian cecal size
TLDR
The best-fitting regression model supports the dietary hypothesis for the avian cecum, with mean cecal length significantly longer in herbivorous species than in carnivorous ones (p = 0.008), presumably allowing the extraction of nutrients without the burden of fermenting bulky masses of dietary fiber.
Wild black bears harbor simple gut microbial communities with little difference between the jejunum and colon
TLDR
It is determined that the jejunum and colon of black bears do not harbor significantly different GMB communities: both gastrointestinal sites were dominated by Firmicutes and Proteobacteria.
The Link between the Appendix and Ulcerative Colitis: Clinical Relevance and Potential Immunological Mechanisms
TLDR
This literature review assesses the current knowledge about the clinical and immunological aspects of the vermiform appendix in IBD and suggests that the idea of the appendix as a vestigial remnant should be discarded.
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