A research team from the University of Geneva (UNIGE), in Switzerland, has observed that exposure to warmer ambient temperatures (34 °C) may help prevent osteoporosis.
During the study carried out on mice, the team found that heat enhances the composition of gut microbiota. With heat, the synthesis of polyamines increases, which affects the activity of osteoblasts (the cells that build bones) and reduce the number of osteoclasts (the cells that degrade bones). The study was published in the Cell Metabolism journal.
In one experiment, the researchers placed newborn mice at a temperature of 34 °C in order to minimize the heat shock associated with their birth. They found that they had longer and stronger bones, confirming that bone growth is affected by ambient temperature.
By placing several groups of adult mice in a warm environment, the scientists observed that while bone size remained unchanged, bone strength and density were largely improved. They then repeated their experiment with mice after an ovariectomy, and found that heat protected them from osteoporosis that usually follows such a procedure, and could protect women from the osteoporosis that occurs after menopause.
The Geneva scientists wanted to understand the role of the microbiota in this effect, so they transplanted the microbiota of mice living in a 34° environment to osteoporotic mice, whose bone quality was rapidly improved.
"These findings suggest that the effects of warmth favors bone density and strength during adulthood through microbiota alterations," lead author Mirko Trajkovski wrote in a report published on the UNIGE website.
In order to be able to use this knowledge to develop therapeutic strategies, scientists must identify precisely the role of particular bacteria in particular diseases.
"We still need to identify candidate bacteria, and develop several 'bacterial cocktails' to treat metabolic and bone disorders, such as osteoporosis," Trajkovski concluded.