The dual role of the gut bacteria in dogs with arthritis.
Do dogs with arthritis have a different microbial profile than healthy dogs?
Yes. Dogs with arthritis have higher levels of Megamonas and significantly lower levels of Paraprevotellaceae, Porphyromonadaceae, and Mogibacteriaceae.
Joint pain/arthritis is caused by chronic low-grade systemic inflammation, when dysbiosis happens to the gut bacteria, the whole host (dog) suffers from metabolic and inflammatory diseases including the onset of joint disease.
The gut profile of dogs with joint pain/arthritis.
There is an increase in Megamonas, offering protection to the dog against the inflammatory symptoms of arthritis by fermenting glucose (from fibre) into anti-inflammatory acetate and propionate.
Anti-inflammatory Properties of Acetate and Propionate.
Acetate and Propionate are both SCFAs produced by the gut bacteria in the microbial population of the gut. Both inhibit the release of TNFα caused by the overproduction of LPS. Lipopolysaccharides (LPS) are the outer membrane components of gram-negative bacteria. Does LPS cause inflammation?
Lipopolysaccharide (LPS) is the major component of Gram-negative bacteria cell walls and can cause an acute inflammatory response by triggering the release of a raft of inflammatory cytokines that activate an immune response.
Dogs with arthritis are therefore relying on their microbes to produce SCFAs with immunomodulatory capacities known to positively influence joint health.
Though it’s not all good news as the lower levels of paraprevotellaceae reduce the ability of the body to break down protein and carbohydrates.
Low levels of Porphyromonadaceae, indicate poor metabolism and they also produce chemicals that protect the gut wall and crypt integrity by stimulating the production of stem cells.
Low levels of Mogibacteriaceae are the most prevalent feature of autoimmune disease compared with healthy controls.
What can be done?
Using soil as a beneficial probiotic.
One of the best probiotics for helping to increase levels of the low beneficial bacteria is with ‘good earth’ microbes.
Dogs seem to have a natural affinity to the soil, using the Petbiome database which consists of the microbial analysis of the gut microbiome, we also analyse soil samples for horse owners, concerned about the impact on the health of their grazing animals. When comparing the soil microbes to the content of the dog microbiome it became apparent that the dog shares around 30% of its microbes with the soil.
For soil to be of benefit to the health of the dog it must contain low/no agrichemical pollutants such as glyphosate, have low levels of pathogenic gut bacteria and a good level of alpha and beta diversity.
The best soil microbes to aid arthritis are to be found in the soil of a mixed herb garden, herbs secrete compounds to feed microbes and in exchange encourage the plants to capture essential nutrients and antioxidants.
A half teaspoon of good soil can be added to the dog's daily food ration.
Using polyphenol compounds as a prebiotic
Another way to improve the percentage of gut bacteria that produce acetate and propionate is to add a 3g dose of plants containing polyphenols.
The highest levels of polyphenols are found in the bark of trees, where they protect the tree against disease. Tree polyphenol molecules are too large to pass over the gut wall membrane and remain in the gut where they influence the microbial population of the gut, and promote the production of propionate and acetate.
The best for dogs with arthritis are acacia catechu and smilax (a woody vine)
Polyphenols are themselves anti-inflammatory, the strongest pain-relieving plants are those with red or black fruits such as blackberries, wild blueberries, sloes, and hawthorn. These polyphenols are called proanthocyanidins the highest are found in the fruit and young bark.
Glycosides (polyphenols from hedera, meadow sweet, cloudberry, heather and rose bay willow bay herb) are extracted by microbial action in the large and small intestine and are rapidly absorbed by the cells of the gut wall, where they are used to reduce inflammatory cytokines.
Polyphenols are anti- microbial and will help to reduce the LPS produced by gram-negative bacteria that trigger the onset of arthritis, the best anti-microbial compounds for dogs are also found in acacia catechu and smilax.
Cintio, M., Scarsella, E., Sgorlon, S., Sandri, M., & Stefanon, B. (2020). Gut microbiome of healthy and arthritic dogs. Veterinary Sciences, 7(3), 92.