Effects of Long-Term Intervention with <i>Lactobacillus helveticus-</i>Fermented Milk on Bone Mineral Density and Bone Mineral Content in Growing Rats

<i>Background:</i><i>Lactobacillus helveticus-</i>fermented milk has been shown to increase calcium absorption compared to ordinary sour milk. In the present study the possible effect of <i>L. helveticus-</i>fermented milk on bone was studied in growing rats. <i>Methods:</i> Spontaneously hypertensive male rats, which develop an osteoporotic bone disorder with age, were randomized into 5 groups (n = 10) receiving milk fermented with <i>L. helveticus</i> 16H and, as reference drinks, milk fermented with <i>L. helveticus</i> and <i>Saccharomyces cerevisiae</i>, sour milk, skim milk or water, for 14 weeks. After the intervention bone mineral density and bone mineral content were measured by dual-energy X-ray absorptiometry. The femur weight, length and volume were measured before ashing. From the ashes the weight and mineral content were assessed. <i>Results:</i> As the body weight gain differed significantly between the groups, the results were related to the body weight. The <i>L. helveticus-</i>fermented milk intervention significantly increased the bone mineral density and bone mineral content compared to the sour milk, skim milk and water interventions. The mean values of the bone mineral density and bone mineral content were higher in the <i>L. helveticus-</i>fermented milk group compared to the <i>Saccharomyces-</i>fermented milk group but the difference was not statistically significant. <i>Conclusion:</i><i>L. helveticus-</i>fermented milk increases bone mineral density and bone mineral content in relation to body weight in the long-term feeding of growing rats. The mechanism of <i>L. helveticus</i> remains to be discovered.