Short-Term Effects of Kefir-Fermented Milk Consumption on Bone Mineral Density and Bone Metabolism in a Randomized Clinical Trial of Osteoporotic Patients

Abstract

Milk products are good sources of calcium that may reduce bone resorption and help prevent bone loss as well as promote bone remodeling and increase bone formation. Kefir is a product made by kefir grains that degrade milk proteins into various peptides with health-promoting effects, including antithrombotic, antimicrobial and calcium-absorption enhancing bioactivities. In a controlled, parallel, double-blind intervention study over 6 months, we investigated the effects of kefir-fermented milk (1,600 mg) supplemented with calcium bicarbonate (CaCO3, 1,500 mg) and bone metabolism in 40 osteoporosis patients, and compared them with CaCO3 alone without kefir supplements. Bone turnover markers were measured in fasting blood samples collected before therapy and at 1, 3, and 6 months. Bone mineral density (BMD) values at the spine, total hip, and hip femoral neck were assessed by dual-energy x-ray absorptiometry (DXA) at baseline and at 6 months. Among patients treated with kefir-fermented milk, the relationships between baseline turnover and 6 months changes in DXA-determined BMD were significantly improved. The serum β C-terminal telopeptide of type I collagen (β-CTX) in those with T-scores > -1 patients significantly decreased after three months treatment. The formation marker serum osteocalcin (OC) turned from negative to positive after 6 months, representing the effect of kefir treatment. Serum parathyroid hormone (PTH) increased significantly after treatment with kefir, but decreased significantly in the control group. PTH may promote bone remodeling after treatment with kefir for 6 months. In this pilot study, we concluded that kefir-fermented milk therapy was associated with short-term changes in turnover and greater 6-month increases in hip BMD among osteoporotic patients. Trial Registration: ClinicalTrials.gov NCT02361372

Probiotics in Gut-Bone Signaling

“…Another study, that saw an effect on bone density, involved the treatment of osteoporotic males (64–67 years of age) with Kefir fermented milk for 6 months. The group found a 5% increase in femoral neck bone mineral density measured by DEXA [67]. This study supports a benefit of probiotics on bone health, but it is important to recognize that only 24 subjects were studied and the contribution of calcium in the Kefir was not separated from the effects of the probiotic bacteria.…”

Probiotics for human use

“…) and short‐term improvements in bone health markers in osteoporosis patients by kefir (Tu et al . ).…”

“…Still, even if fermentation-associated microbes are just passing through, there is emerging evidence that they can nonetheless influence the normal microbiota, communicate with the host immune system and exert other positive effects (reviewed in Marco et al 2017). Outcomes of recent clinical trials include improvements in blood pressure in hypertensive adults by fermented milk (Beltran-Barrientos et al 2018), reduction of infectious disease among children by fermented rice or milk (Nocerino et al 2017) and short-term improvements in bone health markers in osteoporosis patients by kefir (Tu et al 2015).…”

Effects of Probiotics, Prebiotics, and Synbiotics on Calcium Homeostasis and Bone Health With Aging: A Systematic Review

“…The numbers of participants were similar and were divided randomly into the intervention group and the control group, among which seven studies were designed as double‐blind trials, and three studies were used cross‐control experiments. The studies met the inclusion were performed in six countries, including America (Holloway et al, ), Japan (Takimoto et al, ), Sweden (Nilsson, Sundh, Backhed, & Lorentzon, ), Taiwan (Tu et al, ), India (Gohel et al, ), and Iran (Asemi et al, ; Farhangi et al, ; Jafarnejad et al, ).…”

“…Two of the four studies reported BMD was included owing to T score report, and the other two studies were excluded from meta‐analysis because of the relative alteration of reported BMD between baseline and end point (Nilsson et al, ; Takimoto et al, ). Finally, six studies were preserved for meta‐analysis (Asemi et al, ; Farhangi et al, ; Gohel et al, ; Holloway et al, ; Jafarnejad et al, ; Tu et al, ). Further details about the included studies were shown in Table S2.…”