Osteoporosis International.2015 Feb;26(2):589-99
Kefir improves bone mass and microarchitecture in an ovariectomized rat model of postmenopausal osteoporosis.
Chen HL, Tung YT, Chuang CH, Tu MY, Tsai TC, Chang SY, Chen CM.
Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, No. 250, Kuo Kuang Road, Taichung 402, Taiwan
SUMMARY: Kefir treatment in ovariectomized (OVX) rats could significantly decrease the levels of bone turnover markers and prevent OVX-inducedbone loss, deterioration of trabecular microarchitecture, and biomechanical dysfunction that may be due to increase intracellular calcium uptake through the TRPV6 calcium channel.
INTRODUCTION: Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to an increased fracture risk. The incidence of osteoporosis increases with age and occurs most frequently in postmenopausal women due to estrogen deficiency, as the balance between bone resorption and bone formation shifts towards increased levels of bone resorption. Among various methods of prevention and treatment for osteoporosis, an increase in calcium intake is the most commonly recommended preventive measure. Kefir is a fermented milk product made with kefir grains that degrade milk proteins into various peptides with health-promoting effects, including immunomodulating-, antithrombotic-, antimicrobial-, and calcium-absorption-enhancing bioactivities.
METHODS: The aim of this study is to investigate the effect of kefir on osteoporosis prophylaxis in an ovariectomized rat model. A total of 56 16-week-old female Sprague-Dawley (SD) rats were divided into 7 experimental groups: sham (normal), OVX/Mock, OVX/1X kefir (164 mg/kg BW/day), OVX/2X kefir (328 mg/kg BW/day), OVX/4X kefir (656 mg/kg BW/day), OVX/ALN (2.5 mg/kg BW/day), and OVX/REBONE (800 mg/kg BW/day). After 12-week treatment with kefir, the bone physiology in the OVX rat model was investigated. Accordingly, the aim of this study was to investigate the possible transport mechanism involved in calcium absorption using the Caco-2 human cell line.
RESULTS: A 12-week treatment with kefir on the OVX-induced osteoporosis model reduced the levels of C-terminal telopeptides of type I collagen (CTx), bone turnover markers, and trabecular separation (Tb. Sp.). Additionally, treatment with kefir increased trabecular bone mineral density (BMD), bone volume (BV/TV), trabecular thickness (Tb. Th), trabecular number (Tb. N), and the biomechanical properties (hardness and modulus) of the distal femur with a dose-dependent efficacy. In addition, in in vitro assay, we found that kefir increased intracellular calcium uptake in Caco-2 cell through TRPV6 calcium channels and not through L-type voltage-operated calcium channels.
CONCLUSION: The protective effect of kefir in the OVX rat model may occur through increasing intracellular calcium uptake through the TRPV6 calcium channel.
Related articles published in our research group:
- Chang YT, Chen CM, Tu MY, Chen HL, Chang SY, Tsai TC, Wang YT, and Hsiao HL. (2011) Effects of osteoporosis and nutrition supplements on structures and nanomechanical properties of bone tissue. J. Mechan. Behav. Biomed. Materi. 4: 1412-1420.
- Wang YT, Chang SY, Huang YC, Tsai TC, Chen CM, and Lim CT. (2013) Nanomechanics insights into the performance of healthy and osteoporotic bones. Nano Lett. 13(11): 5247-5254.
- Chen HL, Tung YT, Tsai CL, Lai CW, Tsai HC, Lin YL, Wang CH, and Chen CM. (2014) Kefir improves fatty liver syndrome through inhibited lipogenesis pathway in leptin-deficient ob/ob knockout mice. Int. J. Obesity 38(9): 1172-1179.
Related patents filed by our research group
- Chen CM, and Chen HL. 2015/3/10-2032/3/9. Milk-fermented product and use thereof. USA Patent, Application number: 14/327,231; Patent Number: US 8,974,840 B2.
- Chen CM, and Chen HL. 2012/11/20. Novel milk-fermented product and use thereof. Taiwan Patent, Application number: 101/124,838; pending.
- Chen CM, and Chen HL. 2014/3/12. Milk-fermented product for treating or preventing metabolic syndrome related disorders, composition the same and use thereof. Taiwan Patent, Application number: 103108814; pending.
Chuan-Mu Chen, Ph.D.,
Professor and Dean
Department of Life Sciences
Office of Research and Development
National Chung Hsing Unversity
250 Kuo Kuang Road, Taichung 402, Taiwan