Sunday, March 16, 2014

Old Crap

Coprolites


Although they sound like a type of sea life, coprolites are fossilized feces.  While they are applicable to many fields (imagine having to look through brontosaurus feces), human coprolites can tell us about our ancestor’s dietary habits, infections, and biome makeup.  Human coprolites have even helps us date the first humans present in North America (though there is valid controversy over the dating).(1,2)

Disease-wise, ancient coprolites have been found to contain most modern parasites, in addition certain bacterial strains.  Clostridium has been identified as early as 1240 CE in fossilized feces.  Evidence of tapeworms, hookworms, mites, lice, and fleas have been identified in coprolites dating back to approximately 4,000 BCE.  Charcot-Leyden Crystals, evidence of diarrhea, were identified in at least one sample of ancient coprolites as well.(3)

Prehistoric coprolites dating from 3500 BCE in the Americas showed a change in diet around that time, shifting from pochote and millet as food crops to cassava, mesquite, maguey, and beans.  Additionally, pollen analysis showed the use of juniper tea, potentially for medicinal reasons.(4)

To-date, coprolites have not been used to identify the prevalence of IBD in earlier societies.  Diseases ranging from tuberculosis to pertussis have been identified, but they were found through the presence of relevant pathogens.(5)  Because there have been no pathogens definitively identified as causing IBD (though previous posts discuss the correlational evidence), this route has not been fruitful.  There is reason, however, to believe that future analysis may yield some information.  Possible avenues for identification include:

·         Mineral analysis.  Based on the likely deficiencies present in IBD, there would be an expected difference in absorption for those with IBD based on other samples from the then-current diet.
·         Pathogen analysis.  Though we haven’t found causal pathogens, correlated pathogen presence may provide indicators of IBD. 
·         Evidence of diarrhea.  Evidence that a coprolite “creator” suffered from diarrhea without corresponding infections being present may be a possible indicator.
·         Protein analysis.  Analyzing the proteins present in coprolites may yield clues as well.(6)  Fecal calprotectin is a protein marker for IBD, and has a possibility of being present in ancient feces.

Unfortunately, little is known about the presence of inflammatory bowel disease through the ages.  Hopefully, coprolites may play a role in the near future in tracing back the history of Crohn’s disease and ulcerative colitis.

Bottom Line


·         Coprolite analysis can provide insight into ancient human dietary intake and the presence of pathogens
·         No published research was found trying to analyze coprolites for markers of IBD, but possible avenues exist for future research.

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1.       Gilbert, M. Thomas P., Dennis L. Jenkins, Anders G√∂therstrom, Nuria Naveran, Juan J. Sanchez, Michael Hofreiter, Philip Francis Thomsen et al. "DNA from pre-Clovis human coprolites in Oregon, North America." Science 320, no. 5877 (2008): 786-789.
2.       Poinar, Hendrik, Stuart Fiedel, Christine E. King, Alison M. Devault, Kirsti Bos, Melanie Kuch, and Regis Debruyne. "Comment on “DNA from pre-Clovis human coprolites in Oregon, North America”." Science 325, no. 5937 (2009): 148-148.
3.       Reinhard, Karl J., and Vaughn M. Bryant Jr. "Coprolite analysis: A biological perspective on archaeology." (1992).
4.       Bryant Jr, Vaughn M. "Prehistoric diet in southwest Texas: the coprolite evidence." American Antiquity (1974): 407-420.
5.       Appelt S, Armougom F, Le Bailly M, Robert C, Drancourt M (2014) Polyphasic Analysis of a Middle Ages Coprolite Microbiota, Belgium. PLoS ONE 9(2): e88376. doi:10.1371/journal.pone.0088376

6.       Newman, Margaret E., Robert M. Yohe II, Howard Ceri, and Mark Q. Sutton. "Immunological protein residue analysis of non-lithic archaeological materials."Journal of Archaeological Science 20, no. 1 (1993): 93-100.

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