A New Approach to Osteoarthritis
Osteoarthritis (OA) is a cause of disability in millions of people around the world, and is a common side effect of obesity. OA is believed to be exclusively due to an erosion of cartilage in the joints. The cartilage disappears over time due to the regular “wear and tear” that accompanies aging, or occurs faster due to overworking the joints (e.g. athletic endeavours), or, in the case of obesity, as a result of excess stress on the joints. However, that viewpoint is now changing, in part due to a new study on mice that came to some interesting conclusions.
Osteoarthritis in Mice
Researchers at the University of Rochester Medical Center began this study (April, 2018, Journal of Clinical Investigation) by feeding mice a high fat diet. Not “good” fat, but a diet based on “bad” fats, which they defined as similar to a Western “cheeseburger and milkshake” diet. After 12 weeks on this diet the mice were diabetic and obese, with nearly double the body fat of the control group, who were fed a healthy diet low in fat.
Upon examination, it was discovered that the colons of these unhealthy mice were full of pro-inflammatory bacteria, and were lacking in beneficial probiotic bacteria, especially Bifidobacteria. And, these changes in the gut microbiome of the mice subjects corresponded with symptoms indicating systemic inflammation.
In both groups of mice, controls and subjects, the researchers had induced osteoarthritis, with a tear in the meniscus, an injury known to cause OA. (Personally, I am appalled at these animal torture studies.) As a result of this specific injury the knees were, of course, also inflamed, but in the obese mice this induced OA progressed much faster than in the control group of lean mice. In the obese mice, nearly all of their cartilage disappeared within 3 months from the time of the meniscus tear.
Now this is where it gets interesting...
When the diets of obese mice were supplemented with a prebiotic (oligofructose) everything changed. The previous effects of obesity on gut bacteria, inflammation, and osteoarthritis were all prevented. In fact, the cartilage in the damaged knees of this group of obese mice (the ones given a prebiotic in their diet) was as healthy as the damaged knees of the lean mice controls.
Prebiotics, including oligofructose (which is a subgroup of inulin), are soluble fibers which cannot be digested, by either rodents or humans. But they do feed specific types of good bacteria, especially Bifidobacteria.
In this study, the prebiotic consumed by the mice served to feed Bifidobacteria, helping them to colonize to the point that pro-inflammatory bacteria were crowded out. In turn, this led to a decrease in systemic inflammation, and reduced the breakdown of cartilage in the knees of the mice.
The oligofructose supplement also improved insulin sensitivity in the fat mice, again due to increasing the production of Bifidobacteria, however it did not improve their body mass or body composition. In other words, it did not counteract the effect of a bad fat diet on their body weight. So, even though the obese mice given oligofructose did not lose any weight (and thus their knees still had to bear the extra load), their joints were much healthier than the previous test group (who did not receive the prebiotic). For the researchers this confirmed the idea that it is inflammation, not biomechanical issues, that cause joint degeneration and osteoarthritis.
According to the lead author of the study, this finding “reinforces the idea that osteoarthritis is another secondary complication of obesity -- just like diabetes, heart disease, and stroke, which all have inflammation as part of their cause. Perhaps, they all share a similar root, and the microbiome might be that common root." (Study)
But do not think that if you are not obese this does not apply to you. Many of us, obese or not, have disrupted gut flora due to years of bad food, certain pharmaceutical drugs, or repeated antibiotic use. Therefore, the lesson here about gut flora, inflammation, and cartilage erosion, can still apply for those in a normal weight category.
Herein Lies the Rub
Mice do not have Thalidomide babies, that is why that drug was given to pregnant women, causing much tragedy, and why rodent studies do not always translate to humans. So, while there are some common areas between mouse and human microbiomes, the bacteria that protected these mice from OA related to obesity differs from the bacteria that might help us.
Bifidobacterium is a category of beneficial bacteria that includes many subspecies including B. longum, B. infantis, B. bifidum, and B. brev, all of which are common to humans. However, the subspecies of Bifidobacterium that protected the mice in this study was B. pseudolongum which is one of the most prevalent species in mammals (especially in mice), but not in humans.
Humans have an abundance of Bifidobacteria in our gut when we are infants (except if we are not breastfed), but the amount decreases substantially after weaning, and continues to decrease as we age.
“During adulthood the levels decrease considerably but remain relatively stable; decreasing again in old age. Colonisation by bifidobacteria is believed to play pivotal roles in maintaining human health. It is associated with a range of beneficial health effects, involved in the maturation of the immune, digestive and metabolic systems and consequently protecting against the susceptibility to various diseases later in life.” (Source)
Thus, it is safe to assume that, while we might not benefit from the same Bifidobacteria that the mice benefited from, we very likely will benefit from elevating our own subspecies of this bacteria family. And, there is a good chance that symptoms of OA may be reduced as a result.
In food, Bifidobacterium are mostly found in yogurt, kefir, and in cheddar and gouda cheeses, but for those dairy intolerant using prebiotic fibers will do the job of elevating their levels quite well. However, those who have been on repeated bouts of antibiotics may wish to use a probiotic supplement that contains Bifidobacteria, in order to re-establish those colonies.
The prebiotic used in our mouse study was defined as oligofructose, which is another name for Fructo-oligosaccharides, often found included in probiotic products.
“Non-digestible oligosaccharides, typically obtained from complex carbohydrates or enzymatically produced from disaccharides, represent a group of glycans that include various prebiotics. Examples of this are fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS), which are among the best documented and most commonly used prebiotics on the European and Japanese markets.”
“The prebiotic effects of FOS, GOS, inulin and lactulose have been thoroughly assessed in human trials and many studies suggest that these carbohydrates are selective by increasing bifidobacterium numbers and decreasing the numbers of E. coli and enterococci (bad bacteria).” (Source) Now a quick look at each of these prebiotic options.
“Fructo-oligosaccharides (FOS) are made up of plant sugars linked in chains. They are taken from asparagus, Jerusalem artichokes, and soybeans, or produced in the laboratory. Fructo-oligosaccharides are used for constipation, traveler's diarrhea, and high cholesterol levels.” (Source)
“Galacto-oligosaccharides (GOS) are made up of plant sugars linked in chains. They are found naturally in dairy products, beans, and certain root vegetables.” (Source)
“Inulin is a starchy substance found in a wide variety of fruits, vegetables, and herbs, including wheat, onions, bananas, leeks, artichokes, and asparagus. The inulin that is used for medicine is most commonly obtained by soaking chicory roots in hot water. Inulin is commonly used by mouth for high blood fats, including cholesterol and triglycerides. It is also used for weight loss, constipation, diarrhea, and diabetes." (Source)
“Lactulose is a colonic acidifier that works by increasing stool water content and softening the stool. It is a man-made sugar solution.”
Lactulose is the most unnatural of these prebiotics, and the one most commonly recommended by doctors. The prebiotic fiber closest to food, and the one of these that I would most recommend, is inulin. (Though inulin appears to be unacceptable for those on a Low FODMAP diet, or those with SIBO.)
All of this reminds me of long ago when I was designing and writing about our first JointStart product, now called JointStart Original (then just called JointStart as it was the only version at the time).
Have a look at what I wrote at that time about Yucca, one of the ingredients in that formula (only found in JS Original): “Yucca – is rich in saponins and includes properties that decrease bacteria endotoxin absorption which can improve cartilage synthesis. Yucca has been shown in double blind studies to be effective in the management of arthritis. It was suggested that the effects were due to indirect effects on the gastrointestinal flora. Bacterial endotoxins have been shown to depress the biosynthesis of cartilage.”
So, this knowledge of bacterial toxins possibly being responsible for causing osteoarthritis has been around for a while. Of course, back then there was much less information on the microbiome, and how to maintain an ideal mix of good bacteria.
It is now clear that we maintain a healthy microbiome with a healthy diet (clearly avoiding bad fats), and consuming fermented foods, along with prebiotic foods or fibers.
Those with osteoarthritis may wish to consider using either our JointStart Original, or JointStart Supreme, which while it contains no Yucca, does contain more anti-inflammatory agents than the Original formula, and so offers more immediate pain relief. (Our JointStart Premium is designed for rheumatoid arthritis.)
And, of course, anyone looking to increase the good bacteria in their microbiome, including the Bifidobacterium, would be well advised to also use our LactoSpore product. Unlike probiotics, this spore-derived supplement functions as a prebiotic.