How your pets alter your immune system

Living with animals may greatly impact our immunity. It could reduce the risk of allergies, eczema, and autoimmune conditions.

The Amish have a unique lifestyle since emigrating from Central Europe to North America in the 18th century. They still practice dairy cattle farming and use horse-drawn transportation, just like their ancestors.

Hollywood scriptwriters, documentary makers, and sociologists have long been fascinated by the Amish. Recently, medical researchers have also taken an interest in their way of life. The Amish seem to defy a concerning modern trend: rising rates of immune-related conditions like asthma and allergies.

While these conditions have increased since the 1960s, they are not as common among the Amish. This difference offers insights into how our immune systems work and how animals affect them.

To understand why the Amish have lower rates of certain immune conditions, scientists studied an Amish community in Indiana in 2012. They also examined another farming group called the Hutterites in South Dakota. Blood samples were taken from 30 children in both communities for detailed analysis.

Both groups share many similarities. The Hutterites also live off the land and follow a low-processed food diet. However, their asthma and childhood allergy rates are four to six times higher than those of the Amish.

One key difference is that Hutterites fully embrace industrialized farming technologies while the Amish do not. As a result, Amish children grow up close to animals and their microbes.

Fergus Shanahan, a professor at University College Cork in Ireland, notes this distinction. Aerial drone photos show that Amish families live on farms with animals nearby. In contrast, Hutterite communities often live miles away from farms.

In 2016, researchers published a landmark study showing that Amish children have lower allergy risks due to their environment's influence on their immune systems. The study found that Amish children had more finely tuned regulatory T cells than Hutterite children. These cells help control unusual immune responses.

Researchers also analyzed dust samples from homes of both groups for bacteria signs. They discovered that Amish children were exposed to more microbes likely from living with animals.

Similar findings emerged globally among other scientists studying children's health on farms. For example, kids growing up near Alpine cows showed protection against asthma and eczema. Other research indicated that having pets during early childhood reduces allergy risk by about 13-14%.

Jack Gilbert from UC San Diego emphasizes this point during his lectures on farm exposure benefits for immunity development.

Since the initial study on the Amish was published, interest has grown regarding animal interactions' protective effects during childhood. Some even wonder if pets could act as "probiotics."

When we live with animals, microbes from their fur can temporarily transfer to our skin. This suggests our microbiome might be influenced by pet microbes—collections of microorganisms living on our skin and gut where many immune cells reside.

Nasia Safdar at the University of Wisconsin is exploring this idea further through potential studies involving pet owners' fecal samples over time.

However, some experts doubt whether non-human animal microbes can integrate into human microbiomes long-term. Gilbert argues there’s no evidence supporting this claim; dog bacteria don’t persistently accumulate in humans’ bodies.

Despite differing opinions on microbial transfer between pets and owners, Safdar believes it's worth investigating further for potential health benefits.

Gilbert proposes another theory: humans evolved alongside domesticated species like dogs and cows over millennia. Our immune systems may recognize familiar microbial signals without permanent residence within us.

Studies show people living with pets develop similar gut microbiomes over time due to shared environments—pets may facilitate microbial exchanges between owners while stimulating each other's immune systems too.

Research continues suggesting that living with pets throughout life can benefit our immunity significantly.

Inspired by studies on the Amish and Hutterites, Shanahan researched Irish travelers who often live closely with various animals like dogs or horses.

He sequenced their gut microbiomes compared to modern Irish populations as well as indigenous groups worldwide resembling hunter-gatherer lifestyles.

Shanahan found Irish travelers’ microbiomes resembled those of indigenous peoples more than settled Irish individuals.

This ancient microbiome may explain low autoimmune disease rates among Irish travelers despite facing other health challenges related to poverty.

Researchers now explore ways reintroducing animals into lives could improve overall health across generations.

For instance, studies at Arizona University examine whether rehoming unwanted dogs helps older adults' physical or mental well-being through enhanced immunity.

Italian researchers created educational farms allowing pet-less children regular interaction with horses; results showed improved gut microbiome profiles afterward.

Gilbert believes exposing kids to diverse bacteria types stimulates better immune management without colonization by animal-specific bacteria.

Having pets encourages outdoor activities like walking which exposes individuals further beneficial environmental microbes according to Liam O'Mahoney at APC Microbiome Ireland.

Owning a dog increases chances for walks in parks where additional useful microbes thrive around us!