Microbiome: Mouse gut bacteria identified and archived
The communities of microbes in the intestine of the mouse, the gut microbiota, have a significant impact on the research output. However, there is still insufficient information available about many bacteria inhabiting the intestine of mice. For the first time, a collection of cultured bacterial strains provides comprehensive information on the mouse gut microbiota: Scientists were able to isolate, characterize and archive a hundred strains in a public collection, including 15 hitherto unknown taxa. DZIF scientists from Munich and Braunschweig were involved in this studies.
Billions of micro-organisms, most of which are found in the intestines, as well as on the skin and other regions of the body, living in symbiosis with the host. These tiny beings are of central importance, and experts refer to them as intestinal microbiota or the microbiome. Decoding its characteristics and obtaining a better understanding of it is what DZIF scientists at the University of Munich (LMU) and the DSMZ in Braunschweig, together with the Central Institute for nutrition and food (ZIEL) at the Technical University of Munich are working on.
76 cultured bacterial species from the mouse microbiome identified and archived
One key to obtaining information about the interactions between gut bacteria and their host are mouse models. However only a handful of mouse intestinal bacteria have been made publicly available and fully characterized so far. This is a highly limiting factor for research. Dr. habil. Thomas Clavel from ZIEL and colleagues describe a new resource in "Nature Microbiology" which, for the first time, contains a hundred cultured bacterial strains from the mouse gut microbiome. For this study, 1500 cultures were examined, and 76 different species were identified and archived.
"The goal of our work was to take a big initial step towards decoding the cultured fraction of gut bacterial communities in mice. There is still a lot left to do. We will be making our work available to scientists around the world and hope that others will also help to find the pieces to complete the puzzle", said Clavel, who has been researching various bacteria in gut microbiomes at the TU Munich for ten years. “Through comparative microbiome studies of patient samples we have learned a lot about the important role gut flora have in preventing infections. In order to gain further insights, we need to conduct analyses with animal models in which we can specifically change the gut flora. The new strain collection is of crucial importance to this,” emphasizes Prof Bärbel Stecher. She develops gnotobiotic mouse models, i.e. mice which have been colonised with known gut flora mixtures or “cocktails”, for research on gastrointestinal infections at the LMU Munich.
New bacteria with specific functions
For the first time, the researchers were able to characterize new bacteria with important functional properties: For example Flintibacter butyricum produces the short-chain fatty acid butyrate from both sugars and proteins—a rare property in the realm of intestinal bacteria. Butyrate is a main product of fermentation in the intestine, and has been shown to have anti-inflammatory and positive effects against metabolic diseases in numerous studies. The collection also contains the first known member of the bacterial family ‘Muribaculaceae’—they predominate in number in the mouse gut, but nothing further is currently known about them.
