The study of prebiotic and probiotic effects on calcium metabolism and bone health is a rapidly growing area of investigation.^1,2 An increasing body of preclinical and clinical literature shows that both pre- and probiotics are essential for improving the intestinal absorption of calcium and other minerals, and that direct modulation of the quantity of bacteria present (i.e. through use of antibiotics) can affect measures of bone health and calcium metabolism.³

Prebiotics are critical components that can be used to modify the type of metabolites produced by the intestinal microbiota. The beneficial effect of prebiotics on the composition and activity of the gut microbiome also acts to preserve gut barrier integrity and decrease intestinal inflammation. Prebiotics benefit calcium absorption via a variety of mechanisms:⁴

• ↑ bacterial fermentation of prebiotics → ↑ SCFA → ↓ pH → ↑ mineral absorption via increased solubilisation → ↓ bone loss
• ↑ bacterial production of phytase enzyme → release of minerals bound by phytates → ↑ availability of minerals → ↓ bone loss
• ↑ immune modulatory action and antioxidant effects → ↓ osteoclast differentiation → ↓ bone loss
• ↓ pro-inflammatory cytokine levels → ↓ epithelial cell inflammation → ↑ calcium uptake → ↑ bone volume fraction

The increased production of bacteria-derived compounds and changes in the expression of cytokines and growth factors (as a result of gut microbiome alterations), results in several local and systemic responses of the immune, endocrine, vascular and nervous systems - all of which contribute to regulate bone cell differentiation and/or function.5 Ultimately, these signals can result in decreased osteoclast activity and/or increased osteoblast activity leading to enhanced bone density, structure and strength.³ 

Pre- and probiotics both play an important role in optimising bone health during periods of rapid growth and in life stages characterized with greater bone mineral loss and fracture risk, particularly post-menopausal women.3 It has been proposed that prebiotics are an effective method for increasing calcium absorption and bone mineral density among individuals with inadequate calcium intakes,¹ and that combining prebiotics sources with a probiotic increases the range of beneficial effects.⁶

These findings highlight the need for practitioners to consider the beneficial role of pre- and pro-biotics in supporting bone health via their action on the gastrointestinal tract and intestinal barrier function, for the maintenance of intestinal homeostasis and for the prevention of exaggerated immune responses that facilitate chronic inflammation.  Practitioners should therefore consider the following treatment approaches:

• Supplement with a multi-strain probiotic in combination with a prebiotic (i.e. inulin, Larch arabinogalactans, pectin, kiwi fruit) to prevent local gut inflammation and permeability promote a healthy gut microflora.2
• Consider bone nutrients and supplement at risk groups with a potent combination of evidence-based nutrients, including Vitamin K2, Calcium, Vitamin D3, and key cofactors including Magnesium, Manganese, Zinc and Boron to promote bone health where diet may be lacking.
• Encourage a Mediterranean-style diet rich in anti-inflammatory and nutrient dense fruits, vegetables, fish and olive oil to support gut health, improve BMD and reduce the risk of fractures.7-10
• Educate patients on diet and lifestyle habits that negatively affect the gut microflora, such as an increased intake of soft drinks, highly processed foods, cigarette smoking and excess alcohol consumption.

 

References

1. Whisner, C.M. and L.F. Castillo, Prebiotics, Bone and Mineral Metabolism. Calcif Tissue Int, 2018. 102(4): p. 443-479.
2. Schepper, J.D., et al., Probiotics in Gut-Bone Signaling. Advances In Experimental Medicine And Biology, 2017. 1033: p. 225-247.
3. McCabe, L., R.A. Britton, and N. Parameswaran, Prebiotic and Probiotic Regulation of Bone Health: Role of the Intestine and its Microbiome. Curr Osteoporos Rep, 2015. 13(6): p. 363-71.
4. Parvaneh, K., et al., Effect of probiotics supplementation on bone mineral content and bone mass density. Thescientificworldjournal, 2014. 2014: p. 595962-595962.
5. Ibáñez, L., et al., Gut microbiome and bone. Joint Bone Spine, 2019. 86(1): p. 43-47.
6. Roller, M., G. Rechkemmer, and B. Watzl, Prebiotic Inulin Enriched with Oligofructose in Combination with the Probiotics Lactobacillus rhamnosus and Bifidobacterium lactis Modulates Intestinal Immune Functions in Rats. J Nutr, 2004. 134: p. 153-156.
7. Rivas, A., et al., Mediterranean diet and bone mineral density in two age groups of women. Int J Food Sci Nutr, 2013. 64(2): p. 155-61.
8. Feart, C., et al., Adherence to a Mediterranean diet and risk of fractures in French older persons. Osteoporosis International, 2013. 24(12): p. 3031-41.
9. Benetou, V., et al., Mediterranean diet and incidence of hip fractures in a European cohort. Osteoporos Int, 2013. 24(5): p. 1587-98.
10. Perez, R. and R. Velasco, Adherence to Mediterranean diet and bone health. Nutr Hosp, 2014. 29(5): p. 989-96.