The 100 trillion bacteria in your gut, collectively known as the gut microbiome, could be the culprit behind the arthritis and joint pain that affects those who are obese or overweight.
A recent study published by the Journal of Clinical Investigation gives insight into this mechanism.
Osteoarthritis is the greatest cause of disability in the United States today. Affecting over 31 million people, osteoarthritis is a common side effect of being obese or overweight. Osteoarthritis, often referred to as "wear and tear" arthritis, in people who are overweight and obese was long assumed to be a consequence of extra stress on the joint, which in the long term caused them to break down. Recent research from the University of Rochester Medical Center provides evidence that the bacteria that make up our microbiome—which is controlled directly by our diet—could be the key driving force behind osteoarthritis.
Researchers found that overweight and obese mice had more harmful bacteria in their guts compared to lean mice. This harmful bacteria caused inflammation throughout the entire body and was leading to rapid joint deterioration. The obese mice were then given a prebiotic supplement, and although it did not help them shed weight, it completely reversed other symptoms and made the guts and joints of obese mice indistinguishable from lean mice.
What a Standard High Fat American Diet Can Do
The research team then fed the mice a diet that was similar to a standard, American diet consisting of high fat foods—think cheeseburgers, french fries and milkshakes. In just 12 weeks on this diet, the mice became obese and diabetic nearly doubling their body fat percentage compared to mice fed a low fat, healthy diet. The small and large intestine of these mice were completely filled with pro-inflammatory bacteria and were entirely lacking the beneficial probiotic bacteria that helps keep our GI tract healthy. This means the rats that were fed the unhealthy, high-fat diet had negative changes in their gut microbiomes that resulted in signs of body-wide inflammation, including in their knees.
Researchers then induced a meniscal tear—a common injury in athletes that is known to progress into osteoarthritis. The osteoarthritis progressed much quicker in the obese mice, with nearly all of their cartilage disappearing within 12 weeks of the tear, compared to the lean mice.
“Cartilage is both a cushion and lubricant, supporting friction-free joint movements,” said Michael Zuscik—the lead researcher. “When you lose that, it’s bone on bone, rock on rock. It’s the end of the line and you have to replace the whole joint. Preventing that from happening is what we, as osteoarthritis researchers, strive to do—to keep that cartilage.”
As research continued, researchers were surprised to find that the effects of obesity on osteoarthritis, gut bacteria, and inflammation was completely prevented when the high fat diet of obese mice was supplemented with a common prebiotic, called oligofructose. The knee cartilage of the obese mice who took the oligofructose supplement was indistinguishable from that of the lean mice.
Prebiotics like oligofructose are hard for rodents and humans to digest, however, our GI tract has good bacteria—such as bifidobacteria— that thrives on these prebiotics. These beneficial bacteria eat prebiotics, and they replicate to take over the pro-inflammatory bacteria. This, in turn, decreases systemic inflammation and slows down cartilage breakdown in the mice’s osteoarthritic knees. These prebiotics even helped to improve the diabetes in the obese mice. The results conclude that reducing inflammation was enough to protect joint cartilage from degeneration and supports the idea that inflammation—not biomechanical forces—drive osteoarthritis and joint degeneration.
At Total Body Health, we use the latest testing that allows us to check the balance of good and bad bacteria in your gut. By addressing the levels of unhealthy bacteria, we are able to help you reduce your overall inflammation and help to protect your joints in the long term. If you or someone you know struggles with arthritis symptoms, or gut symptoms in general, schedule a free 10-minute consult to see how functional medicine can benefit you!