New research has linked lower rates of irritable bowel disorder (IBD) in children to growing up in rural households. The study, which was reported in The American Journal of Gastroenterology, shows that there is a strong link between the development of IBD and environmental pressures - at an early age. This association could be due in part to the changes in the microbiome, the microbes living in our guts, that are seen in people that live in rural and urban areas. It may also be influenced by other factors like diet or genetic background.
IBD is a term that covers several gastrointestinal disorders, including Crohn's disease and ulcerative colitis; symptoms include abdominal cramps, weight loss, bloody stools and inflammation in the digestive tract causing chronic diarrhea. Learn more about the new work from the video.
"Our findings show that children, particularly those under the age of 10, experience a protective effect against IBD if they live in a rural household," explained Dr. Eric Benchimol, a scientist at ICES and a pediatric gastroenterologist at the CHEO Inflammatory Bowel Disease Center, in Ottawa.
"This effect is particularly strong in children who are raised in a rural household in the first five years of life. These are important findings since our previous work shows that the number of very young children being diagnosed with IBD has jumped in the past 20 years. The findings also strengthen our understanding that environmental risk factors that predispose people to IBD may have a stronger effect in children than adults,” he continued.
This study included 45,567 individuals that were diagnosed with IBD; 6,662 patients with IBD lived in a rural environment, while 38,905 lived in an urban setting from 1999 to 2010 in Alberta, Manitoba, Nova Scotia, and Ontario, Canada. The study found an overall incidence of IBD of 30.72 per 100,000 people among the rural population while the rate was 33.16 per 100,000 people in the urban group.
"We've known that in addition to genetic risk factors, environmental factors have been associated with the risk of developing IBD. But this new study demonstrates the importance of early life exposure in altering the risk of IBD, and that needs further study," Benchimol noted.
The researchers took care to avoid some caveats in the study, acknowledging in their report that there is not a uniform, reliable definition of what rural and urban are exactly. As such, the investigators assessed the results by using several different definitions of rural, finding that the strength of the association was dependent on that definition.
More work will be needed to identify the cause or causes of these differences.