The benefits of pet ownership are undeniable. The four-legged members of our families provide companionship, help children learn responsibility and bring much-needed love and joy into our everyday lives. Your furry friend may be doing one more favor, however, by promoting good digestive health for all of the (human) members of your family.

That's right: owning a dog can actually support stronger gut health. This boost in digestive health can potentially lead to incredible improvements in your family's overall health, from alleviating mom's chronic fatigue to helping dad shed those last few pounds to lowering the risk of the children developing common autoimmune diseases such as allergies and asthma. How exactly does Rover do all of this?

Understanding Your Gut Microbiome and the Hygiene Hypothesis

To appreciate the positive role that your dog can play in your family's gut health, you first need to understand the way that your digestive tract functions and the aspects of modern living that have the potential to negatively affect this function.

The foundation of your digestive health lies with your gut microbiome, consisting of trillions of microorganisms. These tiny creatures that make up the gut microbiome play an important role in helping your body carry out key functions, from aiding in digestion of certain foods to taking part in your immune system's barrier function. A balanced microbiome plays a vital role in your digestive tract and beyond; however, an unbalanced microbial population in your gut can cause a wide range of negative health side effects including inflammatory bowel disease, obesity and even cancer.1

What causes this potentially damaging imbalance in your gut's bacterial population? While factors such as antibiotic use, stress and poor dietary habits can all contribute to an unbalanced gut microbiome, one aspect of modern living plays a particularly large role in creating this imbalance: indoor environments that are too clean. In short, our collective efforts to get rid of "bad" bacteria from our homes and offices through the use of disinfectants and constant cleaning has also removed the beneficial bacteria from these environments. Because our gut microbiome is populated by the microorganisms that we come into contact with on a daily basis, spending most of your time in an overly clean indoor space can cause a dramatic imbalance in your gut's microbial population over the long term.

While adults face negative health effects from surrounding themselves with too-clean "indoor microbiomes," children who grow up in such environments never have the chance to fully develop their gut microbiome and thus their immune system. The resulting effects are so prevalent in developed countries that researchers have even given it a name: the "hygiene hypothesis."2 This theory asserts that the rise in autoimmune diseases such as allergies, asthma and type 1 diabetes seen in developed countries over the past several decades is caused by a lack of exposure to bacteria in early childhood. In short, when children are prevented from coming into contact with bacteria while their immune systems are developing, their bodies are more likely to overreact to all microorganisms later in life--and this overreaction leads to a variety of illnesses.

How Rover Can Help Bring Balance to Your Home's "Indoor Microbiome"

If overly-clean indoor environments and unbalanced "indoor microbiomes" are the cause of so many health issues, your dog may be able to provide the solution just by being himself. Dogs are naturally inclined to roll in the dirt outdoors, investigate garbage bins and other germ-laden places, and play with other dogs who are themselves carriers of a wide range of microorganisms. Then they come back indoors, where they introduce all of these microscopic creatures into your previously clean home.

The thought of what your dog tracts in on his paws and fur might make you feel a bit squeamish, but fight the urge to bathe him twice daily. These natural tendencies of our furry friends help increase the microbial diversity in the home. Indeed, one group of researchers found that owning a dog increased the levels of approximately 56 classes of bacteria in the average indoor environment.3 This broader range of microorganisms that a dog exposes your family to can help balance your family's gut microbiomes as well as that of your home--and the resulting health benefits can be incredible.

For example, one Swedish study revealed that children who grow up in dog-owning households are 15 percent less likely to develop asthma than children who are raised in pet-free homes.4 In general, researchers are increasingly finding that children who have their immune system's stimulated by exposure to animal microorganisms within their first three months are less likely to have over-sensitive immune systems later in life. Additional studies have shown that exposure to furry pets in early infancy has a positive impact on a child's gut microbial balance, reducing the incidence of allergies and the chances of becoming overweight in later years.5

Of course, not all of the microorganisms that your dog tracts in your house are harmless or beneficial. Certain animal-borne microbes can cause serious infections, from leptospirosis to salmonella. Thankfully, the solution to this is easy; simply washing your hands regularly is enough protection as you and your family continue enjoy the gut health benefits of dog ownership.

1 Zhang Y, Li S, Gan R, Zhou T, Xu D, Li H. Impacts of Gut Bacteria on Human Health and Diseases. Int J Mol Sci. 16(4): 7493–7519. 2015.

2 H Okada, C Kuhn, H Feillet, J-F Bach. The ‘hygiene hypothesis’ for autoimmune and allergic diseases: an update. Clin Exp Immunol. 160(1): 1–9. 2010.

3 Barberán A, Dunn R, Reich B, Pacifici K, Laber E, Menninger H, Morton J, Henley J, Leff J, Miller S, Fierer N. The ecology of microscopic life in household dust. Proc. R. Soc. B 282: 20151139. 2015.

4 Fall T, Lundholm C; KÖrtqvist, A. Early Exposure to Dogs and Farm Animals and the Risk of Childhood Asthma. JAMA Pediatr. 169(11):e153219. 2015.

5 Tun H, Konya T, Takaro T, Brook J, Chari R, Field C, Guttman D, Becker A, Mandhane P, Turvey S, Subbarao P, Sears M, Scott J, Kozyrskyj A. Exposure to household furry pets influences the gut microbiota of infants at 3–4 months following various birth scenarios. Microbiome 5:40. 2017.