[Effects of calcium on the structure of intestinal microbiota in ovariectomized rats]

To study the effect of calcium content on bone mineral density and intestinal microbiota in ovariectomized rats.

A total of 30 Wistar rats were randomly divided into 3 groups, namely the sham operation group, the model group and the calcium carbonate supplement group. Postmenopausal osteoporosis rats were established by ovariectomy(OVX). After the first week of modeling, each group was intragastric separately. The calcium carbonate solution was given to the calcium carbonate supplement group, and the same amount of sterile water was given to the other two groups. The animals were executed at the end of the 12 weeks. Left femur was taken and bone mineral density(BMD) was detected by dual-energy X-ray absorptiometry. The total DNA of fecal samples was aseptically extracted and the Illumina Miseq platform was to carry out high-throughput sequencing.

Compared with the sham operation group, the body mass increment of rats in the model group was significantly increased, the level of BMD was significantly reduced(P<0. 05), the intestinal microbiota diversity was not significantly changed, the Firmicutes abundance was decreased, and the Bacteroidetes abundance was increased. Compared with the model group, the body mass increment of rats in the calcium carbonate supplementation group was significantly reduced and BMD was significantly increased(P<0. 05). There was no significant change in the intestinal microbiota diversity, Firmicutes were increased, and Bacteroidetes were decreased.

Calcium supplementation can improve bone mineral density and inhibit the increase of body mass during the experiment period, and its mechanism may be related to regulating the structure of intestinal microbiota.