Microbial Diversity of the Digestive Tract Ecosystem : A Model Bioreactor
Doré, J.; Sghir, A. and Mackie, R. I.
Abstract
Many animals of a wide range of orders have a portion of the digestive system adapted to accommodate a fermentation which aids them in digestion and provides them with a variety of nutritional and health benefits. The microbial community inhabiting the gastrointestinal tract is characterized by its high population density, wide diversity and complexity of interactions - comparable to a model bioreactor. The current knowledge of gut microbial diversity is almost exclusively based on the use of classical anaerobic culture techniques. The latter suffer limitations which lead to the recognition that a large fraction of the gut bacterial populations have escaped cultivation. The application of molecular techniques based on sequence comparisons of nucleic acids to the characterization of gut bacterial diversity is giving a completely new insight while at the same time providing a classification scheme which predicts natural evolutionary relationships. Newly acquired information based on 16S ribosomal RNA based methods will be reviewed, emphasizing the relative advantages and limitations of the different approaches and the comparison of diverse digestive ecosystems.