According to newly published study, microbes found in the guts of wild wolves may be the key to treating a debilitating gastrointestinal (GI) condition commonly found in domestic dogs. The study, titled “Phenotypic and Draft Genome Sequence Analyses of a Paenibacillus sp. Isolated from the Gastrointestinal Tract of a North American Gray Wolf (Canis lupus)” was published recently in the journal Applied Microbiology.

The study co-authors — scientists at Oregon State University-Cascades and Oregon State’s Carlson College of Veterinary Medicine — report the existence of a novel strain of bacteria (Paenibacillus) with characteristics of a probiotic, that may prevent inflammatory bowel disease (IBD) in dogs. IBD is a chronic disorder in which dogs have symptoms that include vomiting, lack of appetite, weight loss, a “rumbling stomach,” gassiness, and abdominal discomfort.

At present there is no known cure for this ongoing dysbiosis of the gastrointestinal tract, and there are limited options for treatment,” study co-author Bruce Seal of OSU-Cascades’ biology program said in a news release. “Underlying causes of the condition include an animal’s genetics, environmental factors, the immunological state of the GI tract and, maybe most importantly, an altered gut microbiome.

According to the news release of the study, this research “is an important step toward a dietary supplement or food additive capable of steering the composition of a dog’s gut microbiome back toward that of the wolf, with which it has common ancestry.”

Dogs were the first domesticated animal. The modern dog diet, high in carbohydrates, does not reflect a wolf’s diet — for example, starches in processed dog food are resistant to digestion, and that can have a negative impact on the microbial community in a dog’s GI tract and in turn its gastric physiology.

For their study, the researchers collected GI material from a wolf who died the previous day after being struck by a car. Through preliminary genetic analysis, they were able to isolate 20 different gut bacteria with potential probiotic properties, and then performed whole genome sequencing on a novel Paenibacillus strain. Paenibacillus “encodes enzymes that can digest complex carbohydrates such as starches,” according to the study. It also has gene systems expressing antimicrobials.

Non-toxic, spore-forming bacteria promote anti-inflammatory immune responses in the gut and inhibit pathogen growth. Taking everything into account, this bacterial isolate could be a potential useful probiotic for domestic dogs.

Also, its genome encodes antimicrobials such as a bacteriocin system and chitinase that contribute to its ability to eliminate pathogenic bacteria and fungi. Finally, the bacterium’s genome encodes enzyme genes such as alpha-amylase, cellulase, lipases and pectin lyase indicating it can breakdown nondigestible carbohydrates such as various complex carbohydrates and lipids adding to increased energy for the host.

The research team plans to perform whole genome sequencing on 4 or 5 other bacterial species of the 20 they isolated.
There are two important takeaways from the above information. Number one, the researchers mention “a dietary supplement or food additive capable of steering the composition of a dog’s gut microbiome back toward that of the wolf, with which it has common ancestry.” This is an admission, which we almost never see outside a small group of fresh pet food advocates, that the current state of the gut microbiome of most dogs is less than optimal because it has evolved away from the microbiome of wolves.

Number two, the study co-authors state that the diet of today’s pet dogs (which is often, ultraprocessed kibble), is “high in carbohydrates” and therefore “does not reflect a wolf’s diet.” Further “starches in processed dog food are resistant to digestion,” which can negatively affect the gut microbiome and gastric physiology.

Although digestive supplements can help improve your dog’s digestion of high carb diets, the preference is to simply feed dogs a continually diversified, nutritionally optimal, species-specific, fresh food diet after weaning and for a lifetime. In another recent article, a study published in 2023 looked at links between what puppies are fed and the incidence of chronic enteropathy (CE) later in life. Chronic enteropathy is a form of IBD characterized by inflammation in the GI tract.

The study was based on longitudinal data and a food frequency questionnaire designed to gather information about early life diets. Results revealed significant associations between what puppies are fed and their risk for CE as adults.

The Study says Specifically:
Feeding a non- or minimally processed meat-based diet from age 2 months to 18 months was associated with a decreased incidence of CE; this diet included raw red meat, organ meats, fish, eggs, tripe, bones and cartilage, vegetables, berries, fruits, and fat supplements in the form of fish and vegetable oils and animal fat.

Feeding an ultraprocessed, carbohydrate-based diet, specifically kibble, during the same period increased the potential for development of CE later in life.

The study authors found that feeding a non-processed meat-based diet and giving the dog human low salt meal leftovers and appropriate table scraps during puppyhood and adolescence were protective against chronic enteropathy later in life.
The study results revealed that specific food items fed to puppies and adolescent dogs play a protective role against CE, specifically, raw bones and cartilage (the protective effect of which increases with higher feeding frequencies), and berries. The researchers discovered that eating human meal leftovers and table scraps in early life had a significantly protective effect on the incidence of future GI illness. Table scraps included cooked potato, non-sour milk products, cooked poultry and fish and processed meat.

The study highlighted the role of the intestinal microbiome in canine chronic enteropathy, and the fact that offering puppies a non-processed, meat-based diet may encourage development of a balanced GI microbiome, contributing to intestinal homeostasis (a condition of optimal functioning).

The biodiversity hypothesis, which holds that more microbial exposures in early life promote a healthier immune system, was supported by these study results. The study results provide evidence that minimally processed diets during puppyhood and adolescence may help lessen the risk of CE later in life.

The Best Way to Nourish Your Dog’s Microbiome
While there are many environmental and lifestyle factors that influence your dog’s gut health, the diet you feed has a direct effect on the microbial diversity of the microbiome and is the single most important factor in preventing illness and maintaining wellness.

If you haven’t already, I recommend transitioning your pet away from “fast food” (kibble), and instead, feed a nutritionally optimal, species-specific diet, which means human-grade food containing unadulterated, high-quality animal protein, moisture, healthy fats and fiber, with low to no starch content. If you must feed highly refined foods for financial reasons, adding in as much fresh food, in the form of treats and toppers, is important and can be very beneficial even if it’s only 25% of what they eat.

A variety of nutritionally complete raw or gently cooked homemade diets is the top choice for pets, but only for those pet parents who are committed to doing it right. If you don’t want to deal with balancing diets at home, choosing to feed a pre-balanced, commercially available fresh food is a good alternative.