PROBIOTICS MODULATE THE GUT-BONE-MICROBIOTA AXIS IN OVARIECTOMIZED MURINE MODEL

Kim S.
Korea University, South Korea

Introduction:
Osteoporosis is a significant health burden and “silent epidemic”, affecting millions of people worldwide. It has been reported that approximately 30 % of all postmenopausal women have osteoporosis in the United States and Europe. This disease is characterized by imbalance between bone formation and bone resorption, leading to an increased incidence of bone fragility and increased risk of bone fractures. The gastrointestinal tract has been initially demonstrated to affect bone metabolism and is frequently associated with the presence of inflammation. In addition, the gastrointestinal tract harbors a complex and largest microbial community, which can contribute to host health. More recently, a complex role of the gastrointestinal tract in the maintenance of bone health via “gut-bone-microbiota” axis has become a topic of intense research activity. Interestingly, the gut-microbiota composition is affected by factors, such as dietary, which can be potentially used as a means to manipulate an altered state in favour of bone health maintenance. Probiotics are defined as “living microorganisms, which when administered in adequate amounts confer health benefits on the host”. Probiotic strains, including Lactobacillus, are capable of restoring the composition of the gut microbiota, and introducing beneficial functions to gut microbiota community, leading to amelioration of gut inflammation and the other systemic disease phenotypes. Thus, probiotics may exert beneficial impact on bone health via gut-bone-microbiota axis.

Methods:
In this study, the potential ameliorating effects of Lactobacillus fermentum MF 27 and Lactobacillus casei 393 on gut-bone-microbiota axis was determined using ovariectomized rat model. Female Sprague-Dawley rats were ovariectomized, and orally treated with L. fermentum MF27 and/or L. casei 393 (109 CFU/mL/day) daily for 8 weeks. Intestine and liver were collected for biochemical and histopathological analysis. Meanwhile, faecal samples and bone (whole femora, cortical bone) were also collected for gut microbiota and bone turnover analyses, respectively.

Results:
Oral administration of  L. casei 393 significantly reduced body weight gain, serum levels of triglycerides, and cholesterol in the ovariectomized rats compared to the control. A reduction of expression of inflammatory markers in bone and intestine were also observed in the ovariectomized rats administered with L. fermentum MF 27. Meanwhile, qRT-PCR and micro-CT bone analysis further revealed that oral administration of these Lactobacillus strains modulate bone physiology and bone turnover by down-regulating osteoclastogenesis, and increasing bone mineral density in the ovariectomized rats. Fecal microbiota analysis also demonstrated that these Lactobacillus strains could modulate altered gut microbiota in the ovariectomized rats.

Discussion:
Hence, these results collectively demonstrate that oral administration of probiotics could modulate “gut-bone-microbiota” axis, thereby mitigating inflammation and improving bone health.

Keywords: Lactobacillus, Gut microbiota , Inflammation, Osteoporosis, Bone, Probiotics

Citation:
Kim S. (2016). Probiotics modulate the gut-bone-microbiota axis in ovariectomized murine model. Conference Proceedings of IPC2016. Paper presented at the International Scientific Conference on Probiotics and Prebiotics, Budapest (p. 36.). IPC2016

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