A chain reaction in the gut
New research suggests that losing beneficial gut bacteria during inflammation may open the door to new food sensitivities in people with inflammatory bowel disease, or IBD. The finding adds to a growing picture of how the microbiome shapes immune reactions to food.
IBD includes Crohn's disease and ulcerative colitis. Both involve chronic inflammation of the digestive tract, with symptoms that range from cramps and diarrhoea to weight loss and fatigue. Many patients report that certain foods make symptoms worse, but the biology behind those reactions has been difficult to pin down.
Why the microbes matter
The gut hosts trillions of bacteria that help break down fibre, train the immune system and keep the intestinal lining intact. When inflammation flares, the mix of species shifts. Helpful strains decline, and more aggressive ones expand.
The study suggests this shift can leave the immune system primed to react to proteins it previously ignored. In effect, the loss of tolerance follows the loss of certain bacteria. That would help explain why patients often develop new food reactions during a flare rather than at the start of their illness.
Researchers point to several mechanisms that could be involved. Certain bacteria help maintain the mucus layer that keeps food proteins away from immune cells. Others produce compounds that calm inflammation. When those species fall away, the barrier weakens and immune cells meet more undigested protein than they normally would.
What it could mean for patients
The work is early, and the authors say more research is needed before it changes clinical advice. Still, it points to two possible directions: restoring key bacterial strains, or targeting the immune signals that drive the reaction.
Doctors also caution against cutting out many foods without medical guidance, because restrictive diets can lead to nutrient gaps, especially in people already losing weight. For now, specialists say the practical advice stays the same: control inflammation, keep regular appointments, and build any diet changes with a clinician or dietitian rather than from online lists.