Effects of Lactobacillus acidophilus and L. reuteri on bone mass and gut microbiota in ovariectomized mice

Abstract

Lactobacillus acidophilus (LA) and L. reuteri (LR) are widely used as food additives or medications in our daily lives. In OVX mice, LA and LR have been proven to inhibit bone loss. This study set out to find out how L. acidophilus and L. reuteri affected the bone mass of OVX mice and the mechanisms that underlie such effects. Fifty C57BL/6J female mice aged 6 weeks were subjected to five different treatments: sham surgery (sham), OVX surgery (OVX), OVX+LR (OVX and L. reuteri fed), OVX+LA (OVX and L. acidophilus fed), OVX+LR+LA (OVX and both L. reuteri and L. acidophilus co-fed), respectively. OVX mice were reared in groups until 16 weeks of age. Serum samples were collected, and IL-1β, IL-6, TNF-α, and OCN levels were determined by ELISA. Bilateral femur thin-layer scanning was performed utilizing a micro-CT scanner. The scanning area was the entire femur. The sample data for bone density were produced via 3D multi-model software after the scanning procedure. To examine the microbial composition and characteristics, Illumina high-throughput sequencing was performed on mice feces. Following probiotic feeding, OVX mice showed an increase in trabecular number and thickness, bone volume fraction, and a reduction in trabecular separation. Blood levels of IL-1β, IL-6, and TNF-α substantially dropped. The observed Chao1 and ACE indexes increased significantly. Changes in intestinal microorganisms occurred in all groups of mice. The change of the index in the gut microbes may indicate that the bone mass of OVX mice is changing. In OVX mice, Lactobacillus acidophilus shares the same role as L. reuteri in preventing bone loss. There are precise principles governing the changes in gut microbial diversity, the richness of certain bacteria, and inflammatory factors in bone metabolism following the administration of Lactobacillus acidophilus or/and L. reuteri.