Inflammation of the joint or arthritis can be presented in many different forms. The most common of them are osteoarthritis and rheumatoid arthritis, both are synonym with joint pain. Osteoarthritis, often referred to as the “wear and tear” arthritis, involves the slow degradation of cartilage. Situated between bones, cartilage act as a cushion and lubricant, allowing friction-free joint movements.
Obesity is believed to accelerate osteoarthritis as it exerts extra strain on the joints due to the excess body weight. But osteoarthritis occurs in both weight-bearing and non weight-bearing joints, indicating a more systemic cause. New research highlighted a more intriguing mechanism that links obesity to osteoarthritis: gut bacteria.
Gut bacteria and inflammation
The global epidemic of osteoarthritis is a reflection of the obesity epidemic, fueled by decrease physical activity and consumption of typical Western diet. 66% of all adults diagnosed with osteoarthritis are reported to be either overweight, obese, or have type 2 diabetic.
Besides the notion that joint overloading is the cause of accelerated osteoarthritis in obesity, research suggests that it is more likely linked to increases in systemic and local inflammation related to obesity.
Researchers from the University of Rochester Medical Center in New York explore the links between diet, obesity, gut bacteria, and osteoarthritis. The researchers fed a high-fat diet to the mice over a 12-week period, causing them to be diabetic and obese with double body fat percentage.
Assessment of their gut bacteria shows widespread pro-inflammatory bacteria and decline of healthy, probiotic bacteria. There is also a concurrent body-wide inflammation in the obese mice, including the knee joints.
The obese mice also develop osteoarthritis faster than in the control mice when cartilage damage is induced by the researchers. In fact, virtually all of the obese mice’s cartilage had gone within 12 weeks.
Good bacteria vs bad bacteria
There are approximately 100 trillion microorganisms within our gastrointestinal tract, 10 times the numbers of cells within our body! Besides other microbes, these essential bacteria are required for fermentation of undigested food components, especially carbohydrates/fibre, and to faecal bulk. Gut microbes also produce a large number of bioactive compounds that can influence health.
The composition of the gut microbiome is dependent on both intrinsic and extrinsic factors, primarily diet and plays a large role in digestion and shaping the immune system. The maintenance of beneficial gut bacteria helps to keep harmful bacteria at bay by competing for nutrients and sites of colonization. Shifts in the gut microbiome can cause the activation of inflammation in obesity.
The correlation between gut bacteria and joint pain is not limited to osteoarthritis only. Rheumatoid arthritis is also discovered to be potentially linked to gut bacteria. A particular bacterium, Prevotella copri, was found in 75% of people with new, untreated rheumatoid arthritis, but only 21% of those without the disease. Once treated with anti-rheumatoid arthritis drugs, the bacterium virtually disappeared. Only one person in ten still had Prevotella copri in their gastrointestinal tract after treatment.
Can we prevent the inflammation?
Interestingly, the inclusion of prebiotic called oligofructose in the osteoarthritis research shows a different outcome. It seems to promote the growth of healthy bacteria and produced a marked reduction in pro-inflammatory bacteria in the mice. Prebiotics (not probiotics) cannot be broken down by mouse or human guts but act as a fertilizer that helps many beneficial bacteria to thrive.
Importantly, it also reduced inflammation in the joints, and the knee cartilage of the obese mice was the same as that of the non-obese control mice. The joints remain healthy although the mice gain excess weight. This also shows that osteoarthritis is mainly due to inflammation induced by obesity, not merely due to weight exertion.
A healthy diet for a healthy joint
Although the research is still limited to animal, prebiotic and probiotic intake may benefit your gut flora and consequently prevent unhealthy development in your joint. Prebiotics are a special form of dietary fiber that nourishes the good bacteria in your gut. Probiotics are live bacteria that can be found in yoghurt and other fermented foods.
Probiotics intake may be beneficial in balancing the gut microbiome but it’s difficult to know which probiotic should you take. There are a whole host of bacterial species that we need and some are not even commercially available. Prebiotic intake seems to be a more sensible strategy as it supports the growth and development of many species of helpful gut bacteria.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: February 18, 2019 | Last Modified: December 1, 2019
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