Small organism with a big impact

18 Jun 2020 | Source: Leibniz Gemeinschaft

By actively intervening in the gut ecosystem, the bacterium Prevotella spp. can increase the susceptibility to inflammatory bowel diseases

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 (

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 (

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 publication

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.