Inflammatory bowel disease (IBD) is a chronic, life-altering condition for those who suffer from it and whose incidence is increasing dramatically around the world.
It is extremely difficult to treat the disease and many people think that the available treatments we have simply do not work in their cases.
Over the past 30 years, there has been an almost 50% increase in the number of cases, now affecting around 5 million people.
The disease should not be confused with irritable bowel syndrome (IBS), which is a condition that affects the digestive system. IBD has other consequences.
The term is used to describe two serious illnesses called Crohn’s disease and ulcerative colitis.
More women are diagnosed with Crohn’s disease, while more men are affected by ulcerative colitis.
People with IBD can experience a variety of symptoms, from diarrhea and blood in the stool to weight loss and stomach pain. This may not seem worse than mild food poisoning. However, this is not a normal tummy ache.
The experiences are often extreme. People with IBD can suffer excruciating pain and, in some cases, require surgery to remove parts of the intestine.
This is done by redirecting the intestine to a hole in the abdomen, where the feces are collected in a colostomy bag.
However, we still do not fully understand the cause of IBD.
The impact of inflammation
The main symptom of IBD is excessive and uncontrolled inflammation, a sign that typically appears when the body fights an infection.
Although inflammation is an important aspect of our immune system, in IBD it occurs when the body is not under attack. As we do not know what causes this exaggerated reaction, treatments are limited to controlling the uncontrolled immune system.
Inflammation is controlled by cell signaling. Our cells detect bacteria using receptors that bind to parts of those bacteria. This activates the receptor, causing it to send a signal to proteins, and each protein sends more signals, creating a signaling cascade. This is what tells the body that it is under attack.
Many treatments follow the strategy of intercepting signals and preventing the signal cascade from starting. However, for many people, these treatments are not effective.
Scientists are trying to target a different protein network, called NOD2, that is often out of control in people with IBD but is not targeted by current treatments.
One protein, called RIPK2, seems a promising target, as it is only found in this network.
Researchers at the European Molecular Biology Laboratory are investigating its structure to help scientists design a new medicine that blocks signals from this protein.
The importance of the microbiome
Another inspiration for new treatments comes from the bacteria in our intestines. This community of bacteria, called the gut microbiome, has been linked to all kinds of health problems, from asthma to obesity.
Gut bacteria work closely with our body and play a vital role in digesting food and controlling our immune system.
In a healthy person, there is a delicate balance between gut bacteria and the immune system. Disruption of this balance can lead to illnesses, ranging from minor discomfort to more serious long-term conditions.
Researchers are trying to understand how our bodies interact with gut bacteria and what changes when people develop IBD.
The gut microbiome is an ecosystem. Just like in a forest there are animals that eat different things, microbes can form a food web. Some bacteria consume one type of food, while others feed on others.
Some depend on waste released by other bacteria after they have eaten. It is now believed that altered gut microbiome is a hallmark of IBD and contributes to its development and progression.
It’s a chicken and egg situation. Is there any change in the bacterial and food network that alters our body? Or does something else in the body, like our immune system, alter the food chain, subsequently limiting the bacteria that can grow?
Scientists are not sure of the answer to these questions.
Rather than trying to figure out what happens first, a team at the Hudson Institute for Medical Research in Australia is focusing on investigating which interactions in the food chain are most affected in IBD.
This could help scientists prioritize certain gut bacteria, or their food source, to restore balance to the microbiome and improve patients’ symptoms.
The hope is that this specialized targeting of the microbiome will lead to more effective and long-lasting treatments.
While we still have a long way to go before these treatment hypotheses become reality, this is a step in the right direction.
Finding a new signaling pathway could help control inflammation in more patients. And studying the microbiome may reveal how we can reverse the changes associated with IBD.
As key features of IBD, these advances could allow doctors to stop the disease in its early stages and reduce complications.
* Falk Hildebran is a Bioinformatics researcher, Quadram Institute, United Kingdom. Katarzyna Sidorczuk is a researcher in Metagenomics, Quadram Institute. Wing Koon, is a PhD student in Bioinformatics, Quadram Institute.
**This article was published on The Conversation and reproduced here under a Creative Commons license. Click here if you want to read the original version (in English).