Writing in the Journal of Internal Medicine, the team think the findings pave the way in preventing fractures among the elderly in an approach designed to pre-empt bone breakages and avoid painful rehabilitative processes.
“Today there are effective medications administered to treat osteoporosis,” said Mattias Lorentzon, chief physician and professor of geriatrics at Sahlgrenska Academy, University of Gothenburg.
“Because bone fragility is rarely detected before the first fracture, there is a pressing need for preventive treatments."
The team’s work with the probiotic—a powder containing the bacteria Lactobacillus reuteri 6475—further confirms previous efforts showing the role the bacteria plays in bone density gains although this has only been observed in mice.
L. reuteri 6475 is a microbe indigenous to the human gastro-intestinal tract with a number of benefits to the host including anti-inflammatory properties.
Inflammation leads to accelerated bone loss due to stimulation of the cells that nibble at and break down bone, which are responsible for bone resorption.
Study details
The randomised, double-blind, placebo-controlled trial, sponsored by Swedish biotechnology company BioGaia AB, set out to investigate the effect of probiotic supplementation on the human skeleton.
At the start of the trial, the bone mineral density (BMD) at the spine, hip or femoral neck were measured and recorded in ninety elderly women, aged 76 years old on average.
These women were asked to take either the study product—a freeze-dried formulation of BioGaia AB’s L. reuteri 6475 in doses of 5x109 colony-forming units (CFU) mixed with maltodextrin powder.
The formulation was taken twice daily, every day for 12 months, yielding a total daily dose of 1x1010 CFU/day. The placebo product consisted of maltodextrin powder only.
"When we finished the study after a year, we measured the women's bone loss in their lower legs with a CT scan and compared it with the measurements we made when the study began,” said Anna Nilsson, study researcher and chief physician and associate professor at Sahlgrenska Academy, University of Gothenburg.
“The women who received the powder with active bacteria had lost only half as much bone in the skeleton compared with those who received inactive powders.
"Another positive outcome from the study was that the treatment was well tolerated and did not produce more side effects than those experienced by women who received the placebo."
A non-pharmaceutical approach?
The team believe the results could provide a proof of concept to the current first-line osteoporosis approach such as bisphosphonates.
While the drug results in much larger effects on bone density, than the observations with L. reuteri 6475, prolonged bisphosphonate treatment of more than 3-5 years is not recommended for patients with low to moderate fracture risk.
"Older women are the group in society most at risk of osteoporosis and fractures,” said Lorentzon.
“Treatment with probiotics can be an effective and safe way to prevent the onset of osteoporosis in many older people in the future."
Despite the potential shown, the team suggested the higher proportion of prevalent fractures in the placebo group at baseline could indicate poorer bone health and perhaps greater bone loss in this group, which could have affected the trial results.
“It cannot be ruled out that the proportion of e.g. vitamin D deficiency was higher in the placebo arm than in the control arm, which could have resulted in augmented bone loss in the placebo arm,” the paper concluded.
“However, arguing against this hypothesis is the fact that there were no baseline differences in bone turnover markers, which would likely be affected by vitamin D deficiency.”
Source: Journal of Internal Medicine
Published online ahead of print: DOI: 10.1111/joim.12805
“Lactobacillus reuteri reduces bone loss in older women with low bone mineral density - a randomized, placebo-controlled, double-blind, clinical trial.”
Authors: Anna G. Nilsson, Daniel Sundh, Fredrik Bäckhed, Mattias Lorentzon