Is your dog protecting you from disease?

Have you ever looked at your dog and thought of all the times they were not only your best friend but your hero too? Dogs are human’s oldest companions and have been by our side for more than 30 thousand years. But not only have they been helping us hunt for food, warning us of danger or allowing us to enjoy their camaraderie, scientists now believe that they can protect us from disease. A recent study found that living with dogs could help create a balance in the gut and immune system that guards against Crohn’s disease.

So how exactly does your furry friend help protect you from Crohn’s disease? Let’s have a look.

What is Crohn’s disease?

Crohn’s is a type of inflammatory disease that affects the digestive tract and bowels. The exact cause of the condition is yet to be discovered but factors like hereditary and a malfunctioning immune system are thought to play a role in its development. And other factors like stress and diet are said to aggravate it. 

The symptoms of Crohn’s disease include:

• Abdominal pain
• Diarrhoea 
• Weight loss
• Rectal bleeding
• Fever
• Abnormal skin tags
• Loss of appetite

However, you will need to be diagnosed by a doctor. Crohn’s disease is a lifelong condition that cannot be cured. But there are ways to manage the symptoms such as taking antibiotics to treat infections or corticosteroids to reduce inflammation. 

How can your dog protect you from Crohn’s disease?

A study, published in Digestive Disease Week, has linked growing up with a dog, or in a large family, with some protection against developing Crohn’s disease. Children between the ages of 2 and 4 years who lived with a dog were 37% less likely to have Crohn’s disease later in life. The study followed just over 4200 participants, who were first-degree relatives of people diagnosed with Crohn’s disease, over an average of 5.6 years. 

The researchers collected urine, blood, stool samples and surveys about environmental exposure from the participants throughout the 5.6 years. They analyzed the size of the family the participants lived with, whether they had cats or dogs, the number of bathrooms in the house, whether they lived on a farm and whether they drank unpasteurised milk and water from a well. The surveys were filled out at the specific ages that the participant was exposed to these environmental factors.

During the time of the study, 86 of the participants developed Crohn’s disease. So how did having a dog protect the others? 

Trusting your gut

The study seemed to support the ‘hygiene hypothesis’ which suggests that the immune system needs to be exposed to enough environmental microbes in early life. This is so that it can learn to self-regulate at optimal levels. 

To cross-check their findings, the researchers compared the gut microbiomes of those who lived with dogs and those that didn’t. 

Children that were exposed to dogs, especially between the ages of 5 and 15, were linked with having a healthy gut. They had a good gut permeability – i.e. their gut lining absorbed water and nutrients into the bloodstream well – and a balance between microbes and immune response. This exposure is said to be what helps with protecting against Crohn’s disease because it boosts the strength of the immune system. 

The researchers also considered another prospective factor which was that dog owners generally spend more time outdoors or live in more green spaces. And this is thought to also expose them to enough microbes to protect against Crohn’s disease. 

Another prospective factor that the researchers found was living with three or more family members. This is possibly also because of the exposure which helps boost the functioning of the immune system.

The takeaway

Crohn’s disease affects around half a million Americans. If you needed another reason, or a little more convincing, to get a dog, this should be it. However, the researchers do agree that the study needs to be replicated and validated to see if the same results will be applicable to other populations. This could include people who never had a dog before and then compare any changes in their gut microbiome after they get one. 

The study may encourage doctors to ask more detailed questions so that they can determine if their patients are at higher risk for Crohn’s disease.