Antibiotics associated with increased risk of inflammatory bowel disease
Antibiotics use, particularly antibiotics with greater spectrum of microbial coverage, may be associated with an increased risk of new-onset inflammatory bowel disease (IBD) and its subtypes ulcerative colitis and Crohn’s disease. That is according to a study by researchers at Karolinska Institutet in Sweden and Harvard Medical School in the United States, published in The Lancet Gastroenterology & Hepatology. The association between antimicrobial treatment and IBD remained when patients were compared with their siblings.

IBD is becoming more common, particularly in Europe, the U.S. and other parts of the world undergoing rapid economic development, increased sanitation, and more frequent use of antibiotics. With growing appreciation for the gut microbiome’s role in maintaining human health, concern has risen that antibiotics may perturb and permanently alter these fragile microbial communities.
This could potential impact the risk of gastrointestinal disease.In what is the largest study thus far linking antibiotic therapy and risk of IBD, researchers in Sweden and the U.S. were able to more definitively demonstrate that more frequent use of antibiotics was associated with the development of IBD and its subtypes, ulcerative colitis and Crohn's disease.
"I think this affirms what many of us have suspected—that antibiotics, which adversely affect gut microbial communities, are a risk factor for IBD," said lead author, Dr. Long Nguyen at Massachusetts General Hospital and Harvard Medical School, Boston, U.S. "However, despite this compelling rationale and seemingly intuitive presumption, there have been no population-scale investigations to support this hypothesis until now."
Through the Epidemiology Strengthened by histoPathology Reports in Sweden (ESPRESSO) study, the researchers identified almost 24,000 new IBD cases (16,000 had ulcerative colitis and 8,000 Crohn’s disease) and compared them with 28,000 siblings, and 117,000 controls from the general population. Prior use of antibiotics (never vs. ever) was associated with a nearly two-times increased risk of IBD after adjusting for several risk factors. Increased risk was noted for both ulcerative colitis and Crohn’s disease with the highest estimates corresponding to broad-spectrum antibiotics.
According to the researchers, earlier studies in the field have been small, and few have had a follow-up beyond a few years. In contrast, the researchers in this study were able to enroll all consecutive, eligible patients with new-onset IBD from a population-based register over a ten-year study period, limiting selection bias.
“In Sweden, there is universal medication coverage with virtually complete information on all drug dispensations, including antibiotics, minimizing ascertainment bias,” says senior author Jonas F Ludvigsson, pediatrician at Örebro University Hospital, and professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “This makes Swedish registers ideal for the study of risk factors for IBD.”IBD affects nearly 1 percent of the Swedish population and can have a substantial effect on patients’ life. It has been linked to an increased risk of both death and cancer. “To identify risk factors for IBD is important, and ultimately our aim is to prevent the disease,” adds Ludvigsson. “Our study provides another piece of the puzzle and even more reason to avoid using antibiotics needlessly.”Funding for this study was provided by the National Institutes of Health, the Crohn’s and Colitis Foundation, the American Gastroenterological Association, the Massachusetts General Hospital and Karolinska Institutet.Publication: “Antibiotic use and the development of inflammatory bowel disease: a national case/control study in Sweden,” Long H. Nguyen, Anne K. Örtqvist, Yin Cao, Tracey G. Simon, Bjorn Roelstraete, Mingyang Song, Amit D. Joshi, Kyle Staller, Andrew T. Chan, Hamed Khalili, Ola Olén, Jonas F. Ludvigsson, The Lancet Gastroenterology & Hepatology,online Aug. 17, 2020, doi: 10.1016/S2468-1253(20)30267-3For more information, please contact:Jonas F. Ludvigsson, professorDepartment of Medical Epidemiology and Biostatistics, Karolinska InstitutetPhone: +46 (0)8-524 823 56Email: jonas.ludvigsson@ki.se
Contacts
Contact the Press Office and download photo: ki.se/pressroom
Images
Karolinska Institutet (https://ki.se/en) is one of the world’s leading medical universities. Our vision is to advance knowledge about life and strive towards better health for all. Karolinska Institutet accounts for the single largest share of all academic medical research conducted in Sweden and offers the country’s broadest range of education in medicine and health sciences. The Nobel Assembly at Karolinska Institutet selects the Nobel laureates in Physiology or Medicine.
Subscribe to releases from Karolinska Institutet - English
Subscribe to all the latest releases from Karolinska Institutet - English by registering your e-mail address below. You can unsubscribe at any time.
Latest releases from Karolinska Institutet - English
Using social media may impair children’s attention8.12.2025 06:01:00 CET | Press Release
Children who spend a significant amount of time on social media tend to experience a gradual decline in their ability to concentrate. This is according to a comprehensive study from Karolinska Institutet, published in Pediatrics Open Science, where researchers followed more than 8,000 children from around age 10 through age 14.
POTS common in patients with long COVID3.10.2025 11:33:37 CEST | Press Release
A new study from Karolinska Institutet in Sweden shows that an unusual heart rhythm disorder, POTS, is particularly common in people with long COVID. The majority of those affected are middle-aged women. The study is published in the scientific journal Circulation: Arrhythmia and Electrophysiology.
Simple test can predict risk of severe liver disease29.9.2025 09:00:00 CEST | Press Release
A new study from Karolinska Institutet, published in the scientific journal The BMJ, shows how a simple blood analysis can predict the risk of developing severe liver disease. The method may already start to be applied in primary care to enable the earlier detection of cirrhosis and cancer of the liver.
Press invitation: Announcement of the Nobel Prize in Physiology or Medicine 202523.9.2025 13:00:00 CEST | Press Invitation
The Nobel Prize in Physiology or Medicine 2025 will be announced on Monday October 6 at 11.30 am CEST (at the earliest).
How mutations in bodily tissues affect ageing20.8.2025 11:00:00 CEST | Pressmeddelande
Two new studies from Karolinska Institutet in Sweden have investigated how mutations that occur in muscles and blood vessels over time can affect ageing. The studies, which are published in Nature Aging, show that such mutations can reduce muscle strength and accelerate blood vessel ageing. The results can be of significance to the treatment of age-related diseases.
In our pressroom you can read all our latest releases, find our press contacts, images, documents and other relevant information about us.
Visit our pressroom

