A large study led by the University of Edinburgh has found that simple stool tests already used in NHS care, combined with information about a person’s diet, may help doctors predict when people with inflammatory bowel disease (IBD) are more likely to have a relapse—even if they feel fine.
The findings were published in the journal Gut and suggest that catching early signs of gut inflammation could help prevent painful and exhausting symptom flares.
IBD includes two main conditions: Crohn’s disease and ulcerative colitis. These conditions affect nearly 1% of the UK population. People with IBD often go through long periods when they feel well (called remission), but then suddenly experience flares of symptoms like stomach pain, diarrhea, and extreme tiredness.
Many people with IBD want to know whether the foods they eat play a role in causing these flares. Until now, there hasn’t been enough strong evidence to give clear answers. This new research begins to change that.
The PREdiCCt study followed 2,629 people with IBD who were all in remission when they joined the study.
They were recruited from 47 NHS hospitals between 2016 and 2020. At the start, each participant gave a stool sample and filled out a food questionnaire. The stool test checked for a marker called fecal calprotectin, which shows whether there is inflammation in the gut.
Participants then completed monthly symptom check-ins and were tracked for about four years. The researchers looked at both “symptom-based flares,” when people reported feeling unwell, and “objective flares,” where inflammation was confirmed by tests and doctors had to increase treatment.
The key discovery was that fecal calprotectin levels could warn of flares before symptoms began. People with higher levels of this inflammation marker—even if they felt healthy—were much more likely to have a flare later on.
For example, in people with ulcerative colitis, the chance of having an inflammation-confirmed flare within two years jumped from 11% for those with low levels to 34% for those with high levels.
The study also found a link between diet and flare risk, but only in people with ulcerative colitis. Those who ate the most meat had about double the risk of a confirmed flare compared to those who ate the least.
This pattern was not found in people with Crohn’s disease, and there was no consistent connection between flares and fiber, alcohol, processed foods, or certain fats.
Experts caution that this study doesn’t prove meat causes flares. It was observational, meaning it looked at patterns rather than testing a specific treatment. But the results are strong enough to encourage future research on whether reducing meat in the diet can help prevent flares in ulcerative colitis.
Professor Charlie Lees, a gastroenterologist at the University of Edinburgh, says this is the first study to track diet and flare risk in such a large group over time.
He says the findings offer a new way to manage IBD: using simple stool tests to detect hidden inflammation early and understanding which foods might affect flare risk. This personalized approach could help many people living with Crohn’s and colitis avoid painful relapses and feel better for longer.
For more information about gut health, please see recent studies about the crucial link between diet, gut health, and the immune system and results showing that Low-gluten, high-fiber diets boost gut health and weight loss.
For more information about gut health, please see recent studies about Navigating inflammatory bowel disease (IBD) with diet and results showing that Mycoprotein in diet may reduce risk of bowel cancer and improve gut health.
The study is published in Gut.
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