How living with a dog or a large family can reduce the risk of Crohn’s disease
- A recent study suggests that having a companion dog or a larger family early in life may protect against Crohn’s diseasea type of inflammatory bowel disease.
- Researchers observed that people who owned a dog as children were less likely to have increased intestinal permeability later in life, which is an early indicator of Crohn’s disease.
- These findings may help understand how environmental factors, such as having a pet dog, may influence the risk of Crohn’s disease.
Owning a dog or growing up in a large family during childhood may reduce the risk of Crohn’s disease later in life, according to a study presented at the Digestive Disease Week conference in San Diego.
The study also reports that owning a dog and having a larger family were associated with changes in gut microbiome composition or gut permeability, paving the way to understanding how these factors influence disease risk. of Crohns.
Study co-author Dr. Williams Turpin, a research associate at Mount Sinai Hospital, said Medical News Today“[ these results] imply that environmental factors are associated with the risk of developing Crohn’s disease, and thus offer new modifiable targets for studies aimed at reducing the risk of developing Crohn’s disease.
Crohn’s disease is a chronic disease that affects approximately 3 million Americans. Crohn’s disease is characterized by inflammation of the digestive tract leading to symptoms such as abdominal pain, weight loss, fatigue and diarrhea.
Genetics is known to play a causative role in Crohn’s disease, with family members of people with Crohn’s disease having a high risk of developing the disease. Besides genetic predisposition, environmental factors also influence the risk of Crohn’s disease.
Studies have shown that diet, exposure to pets, and health conditions in early life can influence the risk of Crohn’s disease. However, the age at which exposure to these environmental factors affects Crohn’s disease risk has not been characterized.
In the current study, researchers examined the association between exposure to environmental risk factors over different time periods and the incidence of Crohn’s disease.
To understand how environmental factors might influence Crohn’s disease risk, the authors also assessed the association between environmental factors and the aforementioned biomarkers.
The current study included 4,289 first-degree relatives of patients with Crohn’s disease enrolled in Crohn’s and Colitis Canada’s Genetic, Environmental and Microbial (CCC-GEM) Project, a global study that seeks to uncover possible disease triggers. of Crohns.
At the time of enrollment, the researchers used a questionnaire to assess these healthy participants’ current and past exposure to eight environmental risk factors. Past exposure to these risk factors was assessed between 0-1, 2-4 and 5-15 years.
The questionnaire assessed exposure to the following risk factors:
- family size
- live on a farm
- consume unpasteurized milk
- the number of bathrooms
- live with a pet
The researchers also measured levels of Crohn’s disease biomarkers at the time of enrollment. After a follow-up period of approximately five and a half years, 86 participants developed Crohn’s disease.
Researchers found that participants who lived with a dog, but not a cat, between the ages of 2 and 4 had a lower risk of getting Crohn’s disease.
“We haven’t seen the same results with cats, although we’re still trying to figure out why. This could be because dog owners go outside with their pets more often or live in areas with more privacy. green space, which has already been shown to protect against Crohn’s disease,” says Dr Turpin.
Living with a dog at any age was also associated with typical gut permeability, and dog owners showed differences in gut microbiome composition compared to those who did not own a dog. These associations with Crohn’s disease biomarkers provide insight into potential mechanisms by which owning a dog may protect against Crohn’s disease.
People raised around a large family with more than 3 members in their first year of life were also less likely to develop Crohn’s disease. Additionally, living with a larger family was associated with changes in the composition of the gut microbiome later in life.
Referring to potential mechanisms that could explain these findings, Dr Turpin said:
“All of this may be related to the hygiene hypothesis, meaning that lack of exposure to microbes early in life may lead to dysregulation of the immune system later on.”
“[H]Having a large family or owning a dog early in life can increase exposure to microbes and thus better educate the immune system, leading to greater tolerance later in life towards commensal (beneficial) bacteria.
— Dr. Williams Turpin
Talk to DTMDr Jean-Frederic Colombel, professor of medicine at Mount Sinai Medical Center, New York, noted that the study only shows a correlation between having a dog or a larger family and the risk of developing the disease. Crohn’s disease and does not provide a mechanistic explanation.
Dr. Colombel also noted that using a questionnaire to assess risk factors could lead to bias.
“[These findings are susceptible to] cognitive bias, which means that when you ask questions, you are asking about the risk factors you are thinking about. [M]maybe we’re missing something much more important that we don’t think about,” he said.
Dr. Ashwin Ananthakrishnan, an associate professor at Massachusetts General Hospital, said it’s also unclear whether these findings extend to ulcerative colitis, another major type of inflammatory bowel disease.
“Further work is needed to examine other biological mechanisms and the specificity of their association with Crohn’s disease or ulcerative colitis,” he said. DTM.