For people living with inflammatory bowel disease (IBD), flare-ups often feel sudden and unpredictable. New research suggests warning signs may appear much earlier, and everyday diet could play a role for some patients.
A large study from the University of Edinburgh, published in Gut, found that elevated gut inflammation detected through routine stool tests strongly predicted future disease flares, even when people reported feeling well. The findings suggest that combining these tests with dietary information could help clinicians identify patients at higher risk of relapse and intervene sooner.
IBD, which includes Crohn’s disease and ulcerative colitis, affects nearly 1% of the UK population. Many people experience long periods of remission followed by painful and disruptive flares that can require medication changes or hospital care. While patients frequently ask whether diet influences these flares, high-quality evidence has been limited.
To better understand the relationship, researchers led the PREdiCCt study, which followed 2,629 adults with IBD who were in remission at enrollment. Participants were recruited from 47 NHS centers between 2016 and 2020 and followed for a median of four years.
At the start of the study, participants completed a detailed food-frequency questionnaire and underwent clinical testing, including a stool test measuring fecal calprotectin, a marker of gut inflammation. They then reported symptoms monthly while researchers tracked both symptom-based flares and objectively confirmed flares that required treatment escalation.
Fecal calprotectin emerged as a strong early warning signal. Higher levels at baseline were associated with a substantially greater risk of future flares, even among people who felt well at the time of testing. In ulcerative colitis, the likelihood of an objective flare within two years rose from about 11% in people with low calprotectin levels to 34% among those with high levels.
The study also identified a dietary signal specific to ulcerative colitis. Participants who reported the highest meat consumption had roughly double the risk of an objective flare compared with those who consumed the least. This association was not observed in Crohn’s disease. Researchers found no consistent links between flare risk and fiber intake, ultraprocessed food consumption, polyunsaturated fats or alcohol.
Because the study was observational, it cannot establish that meat intake directly causes flares. The authors emphasize that the findings should be viewed as a starting point for future clinical trials rather than dietary prescriptions.
“This major study is the first of its kind to properly track the relationship between habitual diet and disease flares in such a large, prospective way,” said Charlie Lees, professor of gastroenterology at the University of Edinburgh. “Our results provide a new framework for management: using objective biomarkers to catch subclinical inflammation early and identifying specific dietary factors that may help prevent debilitating relapses.”
The findings suggest that routine inflammation monitoring, already used in NHS care, could play a larger role in personalizing IBD management. Rather than relying solely on symptoms, clinicians may be able to identify rising risk earlier and tailor treatment or dietary guidance accordingly.
Research support for this study came from UK Research and Innovation, the Scottish Government’s Chief Scientist Office and Cure Crohn’s Colitis.