A team of researchers found that exposure to an ambient temperature above 34°C increased bone strength and prevented the loss of bone density linked to osteoporosis. A phenomenon that would be linked to the composition of the intestinal microbiota.
- An ambient temperature above 34°C prevents osteoporosis by protecting bone strength and density.
- The microbiota plays an essential role: with heat, its composition changes, reducing the number of cells responsible for bone degradation.
Characterized by excessive fragility of the skeleton, due to a decrease in bone mass and the alteration of bone micro-architecture, osteoporosis affects 3 million people in France, including 30 to 40% of postmenopausal women.
While this age-related bone disease is currently incurable, many studies have focused in recent years on ways to prevent its onset. Among them, new work carried out by the University of Geneva (Switzerland). Published in the journal Cell Metabolismthey shed light on the role played by heat in preserving bone strength and density.
Stronger and denser bones
The study, conducted on mice, has in fact observed that exposure to ambient temperatures equal to or greater than 34° C not only increases bone strength, but also prevents loss of density. bone that characterizes osteoporosis.
The experiment was first performed on newborn mice placed at a temperature of 34°C. “We found that they had longer and stronger bones, which confirms that bone growth is affected by ambient temperature”explains Professor Mirko Trajkovski, who led the study.
It was then carried out on several groups of adult mice also placed in a warm environment. The scientists then observed that if the size of the bones remained unchanged, their strength and density were greatly improved. The researchers later repeated their experiment with mice after ovariectomy modeling postmenauposal osteoporosis. “The effect was very interesting, says Claire Chevalier, first author of the work. The simple fact of warming the living environment of our mice protected them from the bone loss typical of osteoporosis!”
A modification of the intestinal microbiota
How to explain this phenomenon ? For the authors of the study, this is linked to the modification of the composition of the intestinal microbiota. To verify this, they transplanted the microbiota of mice living in a 34°C environment into osteoporotic mice, including bone quality.
When it adapts to heat, the microbiota disrupts the synthesis and degradation of polyamines, molecules that are involved in aging, and in particular in bone health. “With heat, the synthesis of polyamines increases, while their degradation is reduced. Polyamines therefore affect the activity of osteoblasts (the cells that build bone) and reduce the number of osteoclasts (the cells that break down bone) With age and menopause, the balance between osteoclast and osteoblast activity is disruptedexplains Claire Chevalier. However, heat, by acting on polyamines, which we found to be partly regulated by the microbiota, can maintain the balance between these two groups of cells.”
Hope for new treatments
Researchers now hope that these discoveries will lead to the development of new treatments for osteoporosis. First objective: to identify the bacteria of the microbiota playing a role in the prevention of bone disease. “We still need to refine our analyses, but our relatively short-term goal would be to identify candidate bacteria and develop several ‘bacterial cocktails’ to treat metabolic and bone disorders, such as osteoporosis, but also to improve the insulin sensitivity, for example”conclude the authors.
.
