Back to Search Start Over

The Commensal Microbiology of the Gastrointestinal Tract

Authors :
Marcus Rauch
Michael S. Gilmore
Janet M. Manson
Source :
Advances in Experimental Medicine and Biology ISBN: 9780387799896
Publication Year :
2009
Publisher :
Springer New York, 2009.

Abstract

The gastrointestinal (GI) tract is a dynamic environment and therefore the stability of the commensal community, or microbiota, is under constant challenge. Microscopic observations have revealed that the majority of bacteria present in the GI tract are not detected using standard culturing techniques, however with the application of culture-independent techniques it has been estimated that between 500 to 1000 bacterial species inhabit the human GI tract. Numerically predominant organisms in the microbiota belong to two eubacterial divisions, the Cytophaga-Flavobacterium-Bacteroides (CFB) and the Firmicutes, and fall into three main groups; Clostridium rRNA subcluster XIVa, Clostridium rRNA subcluster IV and Bacteroides. The prevalence and diversity of bacteria in different areas of the GI tract is influenced by the different conditions at these sites and thus the microbiota of the stomach and jejunum varies with that of the large intestine. Additionally, host genotype, age and diet have all been shown to affect microbial diversity in the GI tract. The distal intestine harbours the highest bacterial cell densities for any known ecosystem. Characterizing the species composition of the healthy microbiota may be a key step in identifying bacterial or associated physiological conditions that are present or absent in an unhealthy microbiota.

Details

ISBN :
978-0-387-79989-6
ISBNs :
9780387799896
Database :
OpenAIRE
Journal :
Advances in Experimental Medicine and Biology ISBN: 9780387799896
Accession number :
edsair.doi...........3cb58398522cf2755e100ad88b2f7206
Full Text :
https://doi.org/10.1007/978-0-387-09550-9_2