There are microbes that normally occupy the eye, ear, mouth, skin, respiratory tract, the genital organs and the gastrointestinal tract. These microbial communities are collectively referred to as the microbiome. Of all the sites in the body, the gut microbiome is considered the most important, the most studied, and has emerged as a key modulator of host health and disease in recent years. 

 

The gut has the largest surface area of any body tissue; and its microbiome is an estimated trillion microbial cells in the GI tract, which is approximately 10 times more than the number of all host cells, and is considered to be a functional metabolic organ, which has in the past few years held up to modern scientific scrutiny regarding the gut microbiome. Before birth all mammals are thought to be sterile, however following birth, a steady symbiosis develops between the new born animal and its indigenous microbiota. Mammals are exposed at the time of birth to microbes via inoculation from the mother and the environment. 

 

The gut microbiota is a dynamic system that can undergo significant changes depending on diet, disease conditions, stress, pathogens and pharmaceutical drugs. This vast gut ecosystem interacts with the host by direct contact between the microbes it is composed of and the metabolites (chemicals/substances produced via bacterial metabolism) they produce. The symbiotic relationship between the gut microbiota and the host is thought to be controlled by these metabolites and have been shown to play a critical role in regulation of metabolic, neuroendocrine and immune functions. 

 

What is Dysbiosis?

Dysbiosis is characterized by changes in the microbial community in diseased states usually with a decrease in the relative proportion and or diversity of bacterial species or changes in the normal microbiota that that develop pathogenic features. 

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Dysbiosis can be measured using the Dysbiosis Index (DI) that is a validated quantitative PCR assay for canine fecal samples that measures the abundance of seven important bacterial taxa and summarizes the results as one single number.

 

Many factors (e.g. antibiotics, NSAIDS, poor diet, psychological and physical stress and other host factors) can induce dysbiosis in the gut microbiome. The major causes in humans and animals are generally the same, especially in regards to the consumption of poor or species inappropriate diets. Although the nature of dysbiosis varies according to the individual, as well as the pathologic condition, reductions in the "good gut bacteria" and increases in "bad gut bacteria" including pathogens like E. coli, Salmonella, Proteus, Klebsiella, and Shigella are common features of dysbiosis in humans and laboratory animals. Dysbiosis and mucosal inflammation are interrelated and multiple studies point to inflammation as either a cause of dysbiosis, a consequence of it, or both. 

 

Dysbiosis does not always involve pathogens, as a decrease or absence of important microbiota can cause problems without the presence of pathogens. Dysbiosis from acute or chronic GIT disease can impair the normal functioning of gut microbiota in maintaining host wellness, and can lead to deficient and or dysregulated production of metabolites from the microbiota and cause a wide range of local, systemic diseases or remote organ dysfunction and disease. Several studies have shown that dysbiosis is a major factor in diseases such as inflammatory bowel disease and chronic diarrhea in dogs and cats. In fact, cats with chronic enteritis/IBD showed patterns of dysbiosis similar to those in found people with IBD!

 

How is Dysbiosis Treated?

In veterinary medicine, fecal microbiota transplant (FMT) is the transplantation of normal microbial populations (depending on species) from a healthy animal to one with dysbiosis or altered gut microbiome. This can be done through capsules by mouth or by enema. Probiotics, Chinese herbal medications, and other supplements are also given to rebalance the microbiome in addition to FMT.

 

How Does Diet Affect the Microbiome?

The adage, “You are what you eat,” is certainly true of the intestinal microbiome. Several studies in different species have shown that diet composition directly affects the microbiome and results in different gut microbiome profiles. The gut microbiome of cats and dogs is increasingly recognized as a metabolically active organ that plays a crucial role in the health and well-being of animals. Many systemic and localized diseases, are associated with dysbiosis. All food consumed is in direct contact with the microbiome and serves as a substrate for the gut microbiome and plays a significant role in defining the composition and metabolism of the gut microbiome. The microbiome, in turn, facilitates the host’s nutrient digestion and the production of metabolites, (bacterially derived compounds) that have direct influence on animal health. Any dysfunction in the microbiome can result in a decline in overall wellness or the development of a variety of diseases both local and remote in the body. It has been shown that the microbiome of cats and dogs can be modified or shaped based on the diets they are fed. Dietary or food therapy is an essential part of a microbiome restoration treatment plan.

 

What Does Microbiome Restoration Therapy Treat?

The use of fecal transplants, herbal medicine, food therapy and other supplements has been shown to be clinically effective in the treatment of diarrhea secondary to antibiotic administration, chronic diarrhea, IBD, hemorrhagic gastroenteritis, asthma, chronic giardiasis and hookworm infection, immune deficiency conditions, diabetes, constipation, anorexia, food allergies, atopy and has been helpful in the control of diarrhea in dogs and cats with intestinal lymphoma. It has also shown efficacy for aggression behavior disorders.