The intestinal microbiome is a highly complex ecosystem with thousands of different types of bacteria. Live and let live that is the motto. Harmonious coexistence is based on the fact that intestinal bacteria occupy different niches and communicate with each other.

The composition of the human gut microbiome is not always the same. There are significant differences between people in different regions of the world in the western highly industrialised world for example different bacteria predominate than in developing countries. On the other hand the gut microbiome varies from person to person in terms of the bacterial species represented and their colonisation density. Despite these differences there are basic patterns of intestinal colonisation in which a particular key bacterium dominates. Segatella copri is the most prominent germ in one of these three so-called enterotypes. This intestinal bacterium is widespread in developing and emerging countries.

Clarifying the health significance of Segatella copri is one of the goals of the research work of Prof Till Strowig head of the Microbial Immune Regulation department at the HZI and group leader in the DZIF research areas Community-Acquired Infections at Mucosal Interfaces and Healthcare-Associated Infections. Cultivating Segatella in the laboratory is difficult but Strowig's team has succeeded. We wanted to find out under which conditions increased colonisation with Segatella copri occurs and which processes take place in the cells. To do this we need insights into how these bacteria work says Till Strowig

The programme for all life processes is encoded in the genes and this is no different in bacteria than in humans. When Segatella copri multiplies and spreads complex metabolic processes are set in motion. To do this the relevant genes have to be transcribed. For this transcription the genetic information is transcribed from DNA deoxyribonucleic acid to RNA ribonucleic acid. We can determine which genes are currently active by examining the so-called transcriptome. This is the entirety of all transcribed RNA molecules in a cell at any given time. While studying the transcriptome of Segatella copri, we came across a tiny snippet of RNA that plays an essential role in the reproduction and spread of the bacterium reports first author Dr Youssef El-Mouali. The small piece of RNA small RNA to use the technical term is significantly involved when Segatella copri breaks new ground. The researchers showed this in mice with a defined gut microbiome.

The researchers also discovered something else: The microbiome's composition influences whether Segatella copri activates the signalling pathway via SrcF. The many different bacterial species that live in peaceful coexistence in the gut compete for available resources and communicate with each other. This is the only way to explain the balanced state of the microbiome The individual composition of the intestinal microbiome is surprisingly constant and even after temporary turbulence the old balance within this ecosystem is usually restored.

Source: https://deutschezentren.de/en/news/microbiome-research-small-rna-molecules-play-crucial-role-in-the-microbial-colonisation-of-the-gut/