Paws for Thought: A Bio of the Biome

EDITOR’S NOTE: Dr. Janice Mitchell is a veterinarian with Island Animal Hospital and Little Current Veterinary Services, and a beekeeper too!

A Bio of the Biome

by Dr. Janice Mitchell

With a rise in the global use of hand sanitizers and household cleaners, I was inspired to write an article in the defence of germs, or as the scientists say, the microbiota. 

The microbiota is the sum of bacteria, fungi, viruses and parasites living in and on a given habitat or host and the microbiome is essentially the collective home of said organisms (ie. the gut microbiome or the skin microbiome). We mammals need our ‘bugs’ to be healthy and to support this fact, I will demonstrate some examples as they pertain to the field of veterinary medicine.

The gut microbiome in healthy adult humans typically contains greater than 1,000 species of bacteria. The average cat likely has more individual organisms within its gastrointestinal (GI) tract than there are people on the face of the earth. The complexity of the microbiome should be thought of as an adaptive, complex, integrated ecosystem—much like a tropical rain forest or the ocean. Individual bacteria should not be labelled as good or bad; rather, it’s the relationships between species and their interaction within the environment that determines the overall GI tract health and function.

So what does this collective bacterial population do for mammals? Or, if asked in another way, what happens when we don’t have a healthy microbiome? In a nutshell: illness. The classic examples include Clostridium Difficile colitis and ventilator-associated pneumonia following acute respiratory disease. Decreased diversity of the gut bacteria has been associated with inflammatory bowel disease, obesity and type 2 diabetes. In germ-free lab animals (ie. mice/poultry), there are reduced populations of immune cells and these animals exhibit major health deficits. Our biome, through its complex symbiotic relationships, not only keeps our guts healthy but other benefits reach beyond the GI tract and affect other organ systems such as skin, brain, kidney and lungs.

The microbiome is disrupted by a patient’s disease process but also we must accept that in large part the disruption of the microbiome in critical illness is iatrogenic—in other words, caused by medical interference. Antibiotic drugs are the primary insult to the microbiome. Other pharmacological disruptions include gastric acid suppression drugs (h2 blockers) and the placement of indwelling lines, catheters and tubes. It is now recognized that administration of drugs like morphine (an opiate) can select for nasty variations of certain bacterial organisms (ie. pseudomonas). The microbiome is definitely under attack.  

Enter the rise of the new mini superheroes—the pre- and probiotics.

Prebiotics are essentially nutrients that feed the bacteria in our gut to encourage their growth—a bacterial ‘boost’ superfood. These would include most dietary fibre sources—eat your greens and garlic! Probiotics are live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host. Think fermented foods such as yogurt, sauerkraut and kefir.

Exmaples of veterinary pre and probiotic choices. Activia yogurt courtesy of a staff member’s lunch.

In veterinary medicine, prebiotics and probiotics are being used to treat acute and chronic diarrheas. There has been substantial research provided by two reputable nutritional pet food companies, Hill’s and Purina, and there has been much anecdotal success using either their Gastrointestinal Biome Diet (a prebiotic food) or the probiotic powder, Fortiflora. Fortiflora has also been used to ameliorate and lessen the severity of respiratory viral illness in cats using shelter settings as research trial sites. As well, another strain of a Purina probiotic, Calming Care, has reduced signs of anxiety in dogs, and this supports the realization that the gut flora can affect mental health as well. Research from the University of Cork in Ireland also demonstrated this same fact with regards to humans and probiotics and mental health. Probiotics are also being used to ameliorate chronic kidney disease in dogs and cats. In dairy cattle, a process called transfaunation has helped to treat indigestion. This is a process whereby a broad spectrum of micro-organisms are transferred from the rumen of a healthy donor to a rumen of a sick recipient animal. The cow is a perfect example of a species that has a symbiotic relationship between its cells and the rumen’s microbiota. A healthy microbiome in a rumen means a healthy cow. 

On the same line, fecal transplantation is another venue being explored whereby a suspension of feces from a healthy individual is infused into the GI tract of another individual, such as in C. Difficile human cases. Research is even showing that our honeybees need pre- and probiotics to stay healthy and that a multi-floral diet is best (trivia fact: lactobacillus is the main bacteria in the honey bee gut).

By now, I hope you are having a bowl of yogurt mixed with some tasty fruit and ready to chase it down with some kefir. Maybe we all can now appreciate the advice given to us when our parents and grandparents say to ‘eat a peck of dirt.’ Happy gut health!