Dogs Help Bacteria Thrive

We first learned about the microbiome In “The Secret Life of Germs,” a fascinating article in the New York Times Magazine. In that article back in 2013, Michael Pollan explored the subject of microbiome—the microbial species as he notes, “with whom I share this body.” The “gut” it seems is all the rage these days. Many writers like Pollan and Mary Roach (author of Gulp) are taking on the subject of bacterial life, many of which resides in our “guts,” and how influential they are to our good health and well-being. There is also a new fascinating book by Dr Robynne Chutkan, The Microbiome Solution, that will be featured in the next issue of Bark (winter 2015), along with an interview with the author.

But back in 2013, Pollan observed that “as a civilization, we’ve just spent the better part of a century doing our unwitting best to wreck the human-associated microbiota with a multifronted war on bacteria and a diet notably detrimental to its well-being.”

From antibiotics (both medicinally and from our foods) and anti-bacterial soaps to our obsession with ridding ourselves of germs and dirt—modern life is destroying our microbial ecosystems—with very harmful results.

It was pointed out that, "This may “predispose us to obesity and a whole range of chronic diseases, as well as some infections.” Also.

Some researchers believe that the alarming increase in autoimmune diseases in the West may owe to a disruption in the ancient relationship between our bodies and their “old friends” — the microbial symbionts with whom we coevolved.

When Pollan pressed the researchers about the best ways to ensure a rich and thriving diversity of microbiome, dogs rank high in their suggestions:

“Some spoke of relaxing the sanitary regime in their homes, encouraging their children to play outside in the dirt and with animals — deliberately increasing their exposure to the great patina.” …

“What about increasing our exposure to bacteria? “There’s a case for dirtying up your diet,” Sonnenburg told me. Yet advising people not to thoroughly wash their produce is probably unwise in a world of pesticide residues. “I view it as a cost-benefit analysis,” Sonnenburg wrote in an e-mail. “Increased exposure to environmental microbes likely decreases chance of many Western diseases, but increases pathogen exposure. Certainly the costs go up as scary antibiotic-resistant bacteria become more prevalent.” So wash your hands in situations when pathogens or toxic chemicals are likely present, but maybe not after petting your dog.”

This underscores the findings from a couple other studies that we also reported on. In these studies researchers looked specifically at how dogs contribute to making children healthier, especially related to respiratory aliments. In one study, conducted in Finland, they found that

Children with dogs at home were healthier overall, had fewer infectious respiratory problems, fewer ear infections and were less likely to require antibiotics. Researchers considered these results supportive of the theory that children who live with dogs during their early years have better resistance throughout childhood. They also found that the effect was greater if the dog spent fewer than six hours inside, possibly because the longer dogs are outdoors, the more dirt they bring inside with them.

And the other conducted by a study team at the University of California, San Francisco found that, “Exposing the gastrointestinal tract to pet dust and other microbes early in life prepares it to respond appropriately to a variety of invaders. But since our modern lifestyles involve living in immaculate houses, our immune systems often overreact instead.” Early childhood is a critical period for developing protection against allergies and asthma, and exposure to pets can help.

Dr. Chutkan also fully endorses the healthful benefits to living with a dog and getting a dog tops her list of "LIve Dirty Lifestyle Dos." Noting too that "children with pets have fewer infections and require fewer antibiotics."

There certainly are many reasons why we consider our relationship with dogs to be mutually beneficial—we provide them with love, mental and physical stimulation, shelter and food. And what research is discovering is that we are only beginning to uncover the extent of the benefits dogs bestow on us.