Oral iron treatment in patients with IBD
In 2024, Dr Thomas Conley was awarded the Guts UK/BSG Trainee Award for his research project that aimed to investigate the impact of oral iron treatment on the gut microbiome in patients with inflammatory bowel disease (IBD).
What’s the project about?
Inflammatory bowel disease (IBD) is a common condition affecting the gut (intestines/bowels). There are two main types of IBD, Crohn’s disease and ulcerative colitis, both of which are lifelong conditions that can significantly alter patients’ quality of life and overall health.
Patients with IBD commonly develop deficiencies (low levels) of vitamins and essential minerals as a result of ineffective gut absorption. The most common deficiency observed in patients with IBD is iron deficiency. Iron is essential for the maintenance of health and wellbeing, and if levels drop patients can develop anaemia (low blood count). This condition is called iron deficiency anaemia (IDA).
IDA is typically treated with iron supplements. These often come in the form of tablets/capsules, syrups or intravenous infusions. Approximately 25% of patients treated with oral iron develop side effects such as abdominal discomfort and change in bowel habit. The high rate of side effects is likely related to the dose of iron supplements which are approximately 10-fold higher than the typical daily intake of iron. Therefore, the supposed intolerance to oral iron in IBD may be related to high doses of oral iron rather than oral treatment itself.
Currently, IBD clinicians tend to treat IBD patients with intravenous iron, which is much more expensive than oral iron. One of the reasons for this is the concern that the use of oral iron in IBD might be a driver of disease activity. Indeed, previous small studies have suggested that oral iron treatment may exacerbate gut inflammation in IBD, perhaps by promoting the growth of certain iron-dependent gut bacteria, but this has never been conclusively proven. Still, studies in mice have demonstrated that supplementation with very high doses of iron results does result in the worsening of gut inflammation, and studies in humans have identified inflammation-related changes in gut chemistry after exposure to oral iron.
Therefore, a better understanding of the clinical and biological impact of oral iron in patients with IBD is needed.
Dr Conley and his team seek to understand the impact of low dose oral iron sumplementation on the gut microbiome, by analysing bacterial populations in stool samples collected by IBD patients with IDA before and after iron therapy.
What impact might it have?
An improved understanding of the biological changes associated with oral iron in IBD patients will enable a pragmatic, more uniform approach to the management of IDA and iron deficiency in patients.
The research also has the potential to benefit clinicians, both in primary and secondary care, by improving understanding of the biology underpinning clinical decision making in these patients and providing much-needed much-needed standardisation to the initial management approach.
I would like to thank Guts UK for supporting this project. Iron deficiency anaemia is a common issue for people with Inflammatory Bowel Disease, but many of our patients struggle to tolerate the iron supplements we recommend. This project will help us explore whether using smaller, easier-to-tolerate doses can be more effective for our patients, while also giving us new insights into how oral iron affects gut biology.
Dr Thomas Conley
What is IBD?
Inflammatory bowel disease (IBD) is a term used to describe a group of chronic, long-term inflammatory conditions that affect the gastrointestinal tract (GI). The two main types of IBD are Crohn’s disease and ulcerative colitis. The main symptoms of IBD include diarrhoea and pain in the belly.
In Crohn’s disease, patients might experience complications that affect nutrient absorption. This can lead to low iron levels, resulting in fatigue and other symptoms.
Why does Guts UK fund research in this area?
Millions of people across the UK live with and are affected by IBD. . Our research leads to earlier diagnosis and kinder treatments for those living with IBD, including Crohn’s disease and ulcerative colitis.
As the national charity for the digestive system, our mission is to improve the lives of people affected by digestive conditions. We are dedicated to investing in the researchers of the future and recognise the insight they bring into the field of gastroenterology.
The Guts UK/BSG training award is a one-year grant for research or audit/quality improvement on any area of gastroenterology, pancreatology and hepatology, and is open to UK-based gastroenterology and allied Specialty Trainees.
