Probiotic supplements prevented bone loss in a postmenopausal mouse model, researchers reported. This finding suggests that probiotics may be a therapeutic strategy for postmenopausal osteoporosis, according to a study published April 25, 2016 in the Journal of Clinical Investigation.
For this study, the researchers removed the ovaries in female mice to replicate the estrogen depletion that occurs with menopause in women. The loss of estrogen in the mice increased gut permeability, activated pro-inflammatory immune cells, and boosted the production of bone-loss cytokines in the intestine, the researchers found. At 1 month after ovary removal, these mice had lost half of their bone density.
When the researchers fed estrogen-deficient mice probiotic supplements, the probiotics reduced gut permeability and tightened gut barrier integrity, dampened inflammation, and completely protected against bone loss.
“Our findings highlight the role that intestinal microbes play in modulating gut permeability and inflammation in the context of sex steroid depletion,” said senior author and endocrinologist Roberto Pacifici, MD, Professor of Medicine in the Department of Medicine at Emory University, in Atlanta, GA.
“We think there are direct implications for the treatment of osteoporosis that should be tested clinically,” he added.
The type of bacteria was important. The researchers treated the mice twice a week with Lactobacillus rhamnosus GG (LGG), a bacteria found in some yogurts, or with VSL#3, a commercially available supplement of 8 strains of probiotic bacteria. In a group of mice whose ovaries weren’t removed, probiotic treatment actually led to an increase in bone density.
By contrast, giving the mice a nonprobiotic strain of E. coli or a mutant strain of LGG did not show a protective effect.