Understanding the role of the microbiome in inflammatory bowel diseases (IBD)

Our body is home to numerous different types of micro-organisms, or microbes – things like bacteria, fungi and viruses – that live on and in us. Their combined genetic material, containing hundreds of millions of genes, is known as the microbiome.1

These organisms can be found all over our bodies, from our skin to our lungs, with the highest concentration of microbes found in the gut. In fact, there are said to be trillions of these tiny organisms in our gut, weighing between one and two kilos in total!

Microbes play such an important role in digestion, metabolism and the immune system that researchers call them a ‘microbial organ’. For example, these microbes help us to break down the food we eat, produce essential amino acids, hormones and vitamins, and protect us from pathogens.

What role does diet play in the health and functioning of the gut? In people with a healthy balanced diet, including lots of fruit and vegetables, the microbiome is varied and diverse – the ‘good’ microbes work in harmony with one another as a community, and protect us from disease-causing or ‘bad’ microbes.

In people with IBD, this balance is disrupted leading to a reduced abundance and diversity of the microbiome. We know that changes in the microbiome and its interaction with the immune system are correlated with the onset of IBD. We all harbour a radically different collection of microbes, however little is known about what leads to the variations and how we can control it.

Importantly, by analysing the microbiome we can begin to understand how different people will respond to different treatments. For example, we know that if a group of IBD patients respond to therapy, their gut bacteria may rebuild back to normal levels. The analysis and manipulation of this community of microbes, which varies from person to person, will help us understand more aboutfor individual people.

Mary Keir, Senior Scientist, Biomarker Discovery at Roche, said: “Better understanding of why IBD patients might or might not respond to treatment has huge implications for the future outlook of the disease. If we can better understand the inner workings of the microbiome, our body’s own community of microorganisms, there is great potential to improve the lives of those living with a complex and severely debilitating disease”.

Understanding the intricate processes of the microbiome and how this affects the onset of IBD is crucial in aiding our goal to improving outcomes for patients living with the disease and will hopefully create opportunities to develop more targeted therapy. Research into the microbiome is just one example of ways in which we can aid our approach to personalised healthcare in IBD, however there are several other examples that we are initiating at Roche. Learn more about ways we are using a new digital tool to help improve IBD care with a more personalised approach, particularly around the challenges faced in IBD patient-to-physician communications:

Jane Grogan, Principal Scientist of Cancer Immunology at Genentech, talks about the latest discoveries in microbiome research with Allyson Byrd, Associate Scientist, Cancer Immunology, Bioinformatics for “Two Scientists Walk Into a Bar.” In Unraveling the Microbiome, take a closer look at the human microbiome and what happens when the synergistic relationship between our cells and our bacteria goes awry.

In Fire in the Gut: IBD Explained, Jane chats with Mary Keir, Senior Scientist, Biomarker Discovery OMNI, to learn what happens during IBD, what causes it, and how targeting dysfunction in our immune system, the gut epithelial barrier and our microbiome could reduce inflammation in the gut.

References

1) Gilbert. J, et al. Current understanding of the human microbiome. Nature Medicine volume 24, pages 392–400 (2018).