Bacteria that cause weight loss and intestinal inflammation have been identified in the microbiome of mice used to study Inflammatory Bowel Disease.
New disease-causing bacteria have been identified in the guts of laboratory mice.
Researchers from the Wellcome Sanger Institute, the Hudson Institute of Medical Research, Australia, the University of Cambridge, and collaborators, have discovered and named two new strains of bacteria in the microbiome of mice that cause Inflammatory Bowel Disease (IBD) symptoms.
A lab mouse. Image credit: Rama via Wikimedia, CC-BY-SA-2.0-FR
The study, published in Nature Microbiology, shows that the bacteria are commonly found in mice used to study IBD and could impact the results of research into this condition. This indicates that it is important to consider the makeup of the gut microbiome when interpreting data. In the future, investigating whether similar strains are found in the human gut could lead to further insight and treatment of IBD.
Inflammatory Bowel Disease, otherwise known as IBD, is a lifelong condition that impacts around 6.8 million people globally each year1. It occurs when there is a chronic inflammation of the gastrointestinal tract and includes ulcerative colitis and Crohn’s disease1. IBD is considered a chronic condition, and when it flares up, it can cause debilitating symptoms that substantially reduce a patient’s quality of life.
While the exact cause of IBD is unknown, it has been suggested that the immune system reacts to the naturally occurring bacteria in the gut in some individuals, highlighting the importance of studying the microbiome in understanding and treating this condition.
In recent years, knowledge of the human microbiome has expanded extensively, but the equivalent investigations in mouse models have remained limited. Research into IBD relies heavily on using a mouse model known as the dextran sodium sulfate, or DSS, to understand what is happening in the gut and the role of genetics in this condition.
While specific protocols have been established to control any effects that known bacterial pathogens could cause in the mouse microbiota, there is still a broad range of bacteria that need to be classified, identified, and understood. Understanding the mouse microbiota and its impact on the disease is essential if this influences results and has implications for any further research.
In this latest publication, researchers studied around 600 mice from a single facility at the Wellcome Sanger Institute and analyzed each microbiome. This large-scale novel approach identified two new bacteria driving weight loss and intestinal inflammation in mice, and researchers named Duncaniella muricolitica and Alistipes okayasuensis.
They found that D. muricolitica and A. okayasuensis are common bacteria in mouse colonies worldwide using data from the previous work2 that cataloged 26,640 mouse microbiome bacteria.
As these bacteria cause IBD symptoms, they impact the outcomes of mouse models for IBD studies. Researchers should note this in designing studies, and if these bacteria are present, the interpretation of the results should consider this.
Source: Sanger Institute