More than a hundred different bacteria in our stomach!

More than a hundred different bacterial species can coexist in our stomach, including usually found in extreme environments, according to a U.S. study published on the website of "Proceedings of the National Academy of Sciences" (PNAS), bacteria that could open avenues of research on the understanding of the stomach and its diseases.
For many years, scientists thought that because of its high acidity, the stomach was only slightly colonized by bacteria. Then the discovery of the bacteria associated with ulcers and gastritis, Helicobacter pylori, has changed the situation, showing that bacteria could be adapted to the gastric environment.

Work on this subject then revealed the presence of some additional bacterial species from cultures of gastric and mucosal biopsies. To go further and identify bacteria were not detected in culture because as helpless to grow well in these conditions, Elisabeth Bik, of Stanford University, California, and colleagues conducted a molecular study .

They amplified nucleic acid (rRNA) of bacteria in samples from biopsies in the stomach of 23 patients and analyzed what they had amplified.

This study has highlighted 128 different bacterial species.

Among them, Helicobacter pylori, obviously. RNA of this bacterium has not only been detected in two patients already identified as carriers by conventional methods, but also in the other seven participants. These should probably be carrying smaller amounts of the bacteria, unless residue dead bacteria are still present in the stomach, the authors assume.

As for the other identified bacterial species, most belonging to Bacteroidetes families Fusobacteria, Firmicutes, Actinobacteria and Proteobacteria.

Of the 128 species identified, 10% were previously unknown. Have been observed including the bacteria Deinococcus family, whose other representatives have previously been found in extreme environments such as ... of radioactive waste sites and sources at very high temperatures!

"A better understanding of microbial communities living in healthy sites and patients should clarify the pathogenesis, diagnosis and treatment of gastrointestinal diseases," the researchers conclude.