Small organism with a big impact: bacterium changes gut ecosystem

Researcher at Leibniz-Institute DSMZ investigates intestinal metabolites

Dr. Meina Neumann-Schaal

Concentration of short-chain fatty acids in the appendix. The control group (SPF) is shown in black, the test group with an intestinal Prevotella spp. overgrowth in green.

How does the bacterium Prevotella spp. influence inflammatory bowel diseases in a mouse model? In a study investigating this question, Dr. Meina Neumann-Schaal, head of the Junior Research Group ‘Bacterial Metabolomics’ at the Leibniz-Institute DSMZ–German Collection of Microorganisms and Cell Cultures GmbH in Braunschweig, found that the presence of this bacterium significantly alters metabolic products in the intestine (cecum or appendix).
In the study, researchers led by Prof. Dr. Till Strowig of the Helmholtz Centre for Infectious Research were able to corroborate the hypothesis that Prevotella spp. can act as immunomodulator in the gut and hence increase the susceptibility to inflammatory bowel diseases. These results are the first indication for the hitherto unexplored communication between gut bacteria and their host. The researchers published their findings in the internationally renowned journal Mucosal Immunology (https://doi.org/10.1038/s41385-020-0296-4).

Other research has already indicated that the presence of gut microorganisms, in particular bacteria, can influence the wellbeing of humans and animals. The intestinal microbiome in particular has been in the science spotlight for some time now, as researchers assume a connection between bacterial gut miscolonisation on the one hand and certain diseases such as chronic inflammatory bowel diseases or rheumatoid arthritis on the other. However, it is still unclear whether bacteria actively intervene in the gut ecosystem and so instigate change, or whether the miscolonisation is a consequence of these changes. The present study shows that bacteria of the gut microbiome such as Prevotella spp. can actively change the intestinal environment of a mouse. For instance, it was demonstrated that Prevotella spp. eliminates other gut bacteria, allowing an increase of its own population. This change in the composition of the gut microbiome also alters local metabolites, ultimately resulting in an increased susceptibility to inflammation. Dr. Neuman-Schaal and colleagues have already published similar results regarding the Citrobacter rodentium bacterium (https://doi.org/10.1371/journal.ppat.1008448).

Metabolomic analyses performed by Dr. Meina Neumann-Schaal at the Leibniz-Institute DSMZ demonstrate that metabolites such as acetate occur more frequently during an overgrowth of Prevotella spp. These findings support the hypothesis that gut bacteria can actively modify their surroundings and thereby influence a person’s susceptibility to develop certain diseases. Meina Neumann-Schaal is a biochemist and heads the Junior Research Group ‘Bacterial Metabolomics’ at the Leibniz-Institute DSMZ; her specialty is the analysis of bacterial metabolites. Based on mass spectrometric analyses such as GC-MS and LC-MS, her working group investigates the metabolism of bacteria and archaea with the goal of gaining a better understanding of their metabolic processes and even being able to influence these. One of Dr. Neumann-Schaal’s major research foci is decoding the link between metabolism and virulence of Clostridioides difficile, a common hospital germ that can cause severe cases of diarrhea. 

Original publikcations:
Iljazovic A, Roy U, Gálvez EJC, Lesker TR, Zhao B, Gronow A, Amend L, Will SE, Hofmann JD, Pils MC, Schmidt-Hohagen K, Neumann-Schaal M, Strowig T. Perturbation of the gut microbiome by Prevotella spp. enhances host susceptibility to mucosal inflammation.
Mucosal Immunol. 2020 May 20. Online ahead of print. 

Osbelt L, Thiemann S, Smit N, Lesker TR, Schröter M, Gálvez EJC, Schmidt-Hohagen K, Pils MC, Mühlen S, Dersch P, Hiller K, Schlüter D, Neumann-Schaal M, Strowig T. Variations in microbiota composition of laboratory mice influence Citrobacter rodentium infection via variable short-chain fatty acid production. PLoS Pathog. 2020 Mar 24;16(3):e1008448. 

Press contact:
Sven-David Müller, Head of Public Relations, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH
Phone: ++49 (0)531/2616-300
Mail: Sven.David.Mueller(at)dsmz.de 

About the Leibniz Institute DSMZ
The Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures is the world's most diverse collection of biological resources (bacteria, archaea, protists, yeasts, fungi, bacteriophages, plant viruses, genomic bacterial DNA as well as human and animal cell lines). Microorganisms and cell cultures are collected, investigated and archived at the DSMZ. As an institution of the Leibniz Association, the DSMZ with its extensive scientific services and biological resources has been a global partner for research, science and industry since 1969. The DSMZ is the first registered collection in Europe (Regulation (EU) No. 511/2014) and certified according to the quality standard ISO 9001:2015. As a patent depository, it offers the only possibility in Germany to deposit biological material in accordance with the requirements of the Budapest Treaty. In addition to scientific services, research is the second pillar of the DSMZ. The institute, located on the Science Campus Braunschweig-Süd, accommodates more than 73,000 cultures and biomaterials and has 198 employees. www.dsmz.de  

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The Leibniz Association connects 96 independent research institutions that range in focus from the natural, engineering and environmental sciences via economics, spatial and social sciences to the humanities. Leibniz Institutes address issues of social, economic and ecological relevance. They conduct knowledge-driven and applied basic research, maintain scientific infrastructure and provide research-based services. The Leibniz Association identifies focus areas for knowledge transfer to policy-makers, academia, business and the public. Leibniz institutions collaborate intensively with universities – in the form of “Leibniz ScienceCampi” (thematic 
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