OpinionMarch 18, 20254 min readNew Drugs, and Diets, Soothe Inflammatory Bowel DiseaseSeveral medications now calm painful inflammation in the intestines. Diets free of ultraprocessed foods also helpBy Lydia Denworth edited by Josh Fischman Jay BendtI recently met a 26-year-old chef named Caroline Horvatits whose story is simultaneously distressing and hopeful. About a decade ago, during high school, Caroline was stricken by gut pain so severe she couldnt sleep and missed her midterm exams. After a colonoscopy, a gastroenterologist diagnosed her with ulcerative colitis (UC), a disease where the bodys immune cells overreact and attack the colonpart of the large intestineleaving open sores in the lining.Colitis is one form of inflammatory bowel disease, or IBD, and there werent a lot of treatment options at the time. Caroline tried some long-standing anti-inflammatory drugs, such as steroids. But her mother worried that they had too many side effects. Eventually, Caroline dropped the drugs and focused on her diet.Her experience wasnt unusual. When gastroenterologist Bruce Sands of the Icahn School of Medicine at Mount Sinai in New York City started practicing 30 years ago, he says, large numbers of his IBD patients couldnt be helped. But much has changed, he says, especially in the past 10 years. There are far more possibleand precisemedications for the more than two million American adults and more than 100,000 children and adolescents with colitis or the other major form of IBD, Crohns disease.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.Both UC and Crohns involve chronic inflammation of the gastrointestinal tract that is terribly painful and distressingly unpredictable. Flare-ups come on suddenly. They can lead to bleeding, cramping, diarrhea and unhealthy weight loss. Whereas colitis occurs in the lining of the colon, Crohns affects the entire GI tract.Every time we find a new mechanism of action, we find another group of patients who can be adequately treated. Bruce Sands, gastroenterologistThe growing variety of drugs target different types of cells in the immune system, and that gives clinicians and patients more options. There are six separate mechanisms of action for these drugs that have been recognized by the Food and Drug Administration. Every time we find a new mechanism of action, we find another group of patients who can be adequately treated, Sands says.The goal of most of these medications is to interrupt inflammation and the ensuing tissue damage. Researchers now better understand how different immune cell types sustain inflammation, and that has led to the identification of more precise targets. Gastroenterologist Alan Moss, chief scientific officer of the New Yorkbased Crohns and Colitis Foundation, says that older drugs such as the steroid prednisone suppress the entire immune system. But we now have drugs that are unique to treating the colon and the cells that attack the colon, he says. What this means, Moss notes, is that people are at much lower risk of getting more systemic side effects such as infections.For example, one of the most recently approved drugs, risankizumab (marketed as Skyrizi), blocks receptors for the cytokine interleukin-23 (IL-23), which is involved in many autoimmune diseases, and thereby interrupts the inflammatory cascade. Still others target cell proteins called phosphate receptors that affect the trafficking of immune cells into GI tract tissues. In 2024 Sands reported successful clinical trials for a drug that binds to TL1A, another protein that moves excessive numbers of immune cells into the bowels.These days theres also more precision in dosing, Moss says. Physicians adjust up or down based on how active the disease is, and they can now account for things such as weight, age and comorbidities.Even so, its estimated that were leaving probably half of our patients without remission, and they tend to cycle through one thing after the other, Sands says. A better way of addressing the disease might be combination therapy. A 2023 proof-of-concept study published in the Lancet reported on 214 patients randomly assigned treatment with a drug that inhibits tumor necrosis factor (TNF, which is the name of the wider family of proteins involved in gut inflammation), or with an anti-IL-23 drug, or with both. Of those who received both drugs, 83 percent achieved remission at 12 weeks versus 61 and 75 percent of those treated with just one drug. Researchers are also working to identify predictive biomarkers that would fine-tune treatment. Pediatric gastroenterologist Sana Syed of the Duke University School of Medicine has studies underway collecting detailed data on blood components, tissue, and more. She will then use machine learning to try to look for signs that indicate which patient will respond to which drug, so she can highlight them at diagnosis.Thats especially urgent in the pediatric population, for whom there are only two FDA-approved treatments, both anti-TNF medications. None of the recently approved or emerging therapies that are currently used to treat adults are within a decade of approval in children, Syed says. Pediatric doctors still use those drugs but do so without precise treatment guidelines.Drugs are not the only way to treat IBD. The past decade has also brought much greater appreciation of the role of environment, Moss says. Nutrition, stress and pollution all are factors. One piece of strong evidence for the particular importance of nutrition is that the incidence of IBD has grown at an alarming pace in parts of the world where it was once rare, such as Asia, Latin America and Africa. Its probably because theyre now adopting our westernized diets, Moss notes. Specific nutritional triggers vary from patient to patient, but ultraprocessed and sugary foods seem to contribute to the disease. Diets high in fiber, fruits and vegetables, however, often reduce symptoms.That is what helped Caroline. Two years of a very limited diet healed her gutand inspired a career. She and her partner now run a small farm in central New York State and have a cooking business focused on fresh food. I live mostly symptom-free, Caroline says. The hope is that, whether with drugs or diet, far more people will soon be able to say the same.This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.