Association between Dysbiosis in the Gut Microbiota of Primary Osteoporosis Patients and Bone Loss

Unveiling the Gut-Disc Axis: How Microbiome Dysbiosis Accelerates Intervertebral Disc Degeneration

The gut microbiome (GM), often referred to as the second genome of the human body, plays a crucial role in various metabolic processes and mediates the development of numerous diseases. Intervertebral disc degeneration (IDD) is an age-related degenerative spinal disease characterized by the loss of disc height, hydration, and integrity, leading to pain and reduced mobility. Although the pathogenesis of IDD is not fully understood, recent studies suggest that dysbiosis of the gut microbiome may accelerate the progression of IDD through multiple mechanisms. This article begins by discussing the potential relationship between GM dysbiosis and human diseases, followed by a comprehensive review of the regulatory mechanisms of GM in skeletal diseases within the gut-disc axis framework. Furthermore, it explores three potential pathways through which GM dysbiosis may mediate the development of IDD: immunomodulation, bacterial translocation and colonization, and the decomposition and absorption of intestinal metabolites. These pathways can disrupt disc cell homeostasis and promote degenerative changes. Finally, this paper summarizes for the first time the potential therapeutic approaches for delaying IDD by targeting the gut-disc axis, providing new insights into the pathogenesis and regenerative repair strategies for IDD.

Characterization of Intestinal Flora in Osteoporosis Patients Based on 16S rDNA Sequencing

Aim

This study investigated differences in gut flora between osteoporosis (OP) patients and healthy individuals using 16S rDNA sequencing. The correlation between differential flora abundance and bone mineral density (BMD) was analyzed, and key flora and potential mechanisms associated with OP were explored.

Methods

Forty-three OP patients and twenty-four healthy volunteers were recruited. Gender, age, height, weight, and BMD data were collected. DNA from fecal samples was extracted for 16S rDNA sequencing. The Kruskal-Wallis test assessed differences in gut flora composition, while LEfSe analysis identified significant flora. Spearman correlation analysis examined the relationship between differential flora and BMD, and PICRUSt predicted pathways involved in OP.

Results

Significant differences in microbial composition were found between the two groups. Klebsiella, Escherichia-Shigella, and Akkermansia were biomarkers in OP patients, with Faecalibacterium in the healthy group. Akkermansia abundance negatively correlated with lumbar BMD, while Klebsiella and Escherichia-Shigella negatively correlated with femoral neck and hip BMD. Faecalibacterium showed a positive correlation with BMD. Functional predictions indicated differences in metabolism-related pathways between the groups.

Conclusion

Gut flora differed significantly between OP patients and healthy individuals. Akkermansia, Klebsiella, and Escherichia-Shigella could serve as diagnostic biomarkers for OP, highlighting the potential of gut flora in OP diagnosis and treatment.

Oral Propolis Nanoemulsions Modulate Gut Microbiota to Balance Bone Remodeling for Enhanced Osteoporosis Therapy

The discovery of the bone-gut axis linking bone metabolism to gut microbiota (GM) dysbiosis has revolutionized our understanding of managing degenerative skeletal diseases. Targeting GM regulation has emerged as a promising approach to osteoporosis treatment. Herein, we develop propolis nanoemulsions (PNEs) with enhanced gastrointestinal stability and oral bioavailability for GM-based osteoporosis therapy. Orally administered PNEs exhibit superior antiosteoporosis efficacy in an ovariectomized (OVX) mouse model by modulating the GM structure and metabolites and restoring the intestinal barrier function. Multiomics analysis reveals that a reduction in Streptococcus abundance and an increase in the GM metabolite l-arginine are key factors in osteoporosis management. These changes suppress osteoclast activity and enhance osteoblast function, leading to balanced bone remodeling and, thus, significant antiosteoporotic effects via the gut-bone axis. Our results deepen insights into the intricate relationship between GM and bone remodeling, suggesting a promising strategy that maintains the homeostasis of the GM structure and metabolite for osteoporosis treatment.

The correlation between traditional Chinese medicine constitution and primary osteoporosis: A systematic review and meta-analysis

BACKGROUND

In recent years, as societal awareness of the risks associated with primary osteoporosis (POP) has deepened, numerous studies have explored the relationship between POP and Traditional Chinese Medicine (TCM) constitution types. To further clarify the TCM constitution types closely associated with POP and provide evidence-based medical support for the prevention and treatment of osteoporosis from a TCM perspective, we have employed evidence-based methods to investigate the relationship between POP and TCM constitution types.

METHODS

We conducted a comprehensive search of observational studies on the relationship between POP and TCM constitutional types in databases, including PubMed, Embase, MEDLINE, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wanfang, and Chinese Scientific Journal Database (VIP), up to October 2023.

RESULTS

After literature selection, data extraction, and bias assessment, 29 studies were included in the meta-analysis, comprising 20 cross-sectional studies and 9 case-control studies. Using R software (version 4.2.3), we analyzed the distribution of TCM constitutional types in POP patients and compared the TCM constitutional types between POP patients and healthy individuals. The meta-analysis results revealed that in POP patients, Yang-deficiency constitution accounted for 22.7% (95% CI: 19.8-25.8%), Yin-deficiency constitution accounted for 15.8% (95% CI: 13.0-18.6%), and Qi-deficiency constitution accounted for 14.1% (95% CI: 12.2-16.0%). The proportions of the three mentioned TCM constitutions all exceed that of the Balanced constitution, with the balanced constitution accounting for 12.3% (95% CI: 7.4-18.1%). The proportions of Yang-deficiency, Yin-deficiency, and Qi-deficiency constitutions were higher in POP patients compared to healthy individuals, with odds ratios (OR) of 2.36 (95% CI: 1.43-3.89), 1.69 (95% CI: 1.36-2.04), and 1.80 (95% CI: 1.23-2.64), respectively, while the Balanced type was lower in POP patients with an OR of 0.16 (95% CI: 0.11-0.23) compared to healthy individuals.

CONCLUSION

The evidence suggests that the Yang-deficiency constitution, Yin-deficiency constitution, and Qi-deficiency constitution are the predominant TCM constitutional types in POP patients. Furthermore, Yang-deficiency constitution, Yin-deficiency constitution, and Qi-deficiency constitution may serve as potential risk factors for POP, while the Balanced constitution may act as a protective factor.

Prediction of Osteoporotic Hip Fracture Outcome: Comparative Accuracy of 27 Immune-Inflammatory-Metabolic Markers and Related Conceptual Issues

Objectives: This study, based on the concept of immuno-inflammatory-metabolic (IIM) dysregulation, investigated and compared the prognostic impact of 27 indices at admission for prediction of postoperative myocardial injury (PMI) and/or hospital death in hip fracture (HF) patients. Methods: In consecutive HF patient (n = 1273, mean age 82.9 ± 8.7 years, 73.5% females) demographics, medical history, laboratory parameters, and outcomes were recorded prospectively. Multiple logistic regression and receiver-operating characteristic analyses (the area under the curve, AUC) were used to establish the predictive role for each biomarker. Results: Among 27 IIM biomarkers, 10 indices were significantly associated with development of PMI and 16 were indicative of a fatal outcome; in the subset of patients aged >80 years with ischaemic heart disease (IHD, the highest risk group: 90.2% of all deaths), the corresponding figures were 26 and 20. In the latter group, the five strongest preoperative predictors for PMI were anaemia (AUC 0.7879), monocyte/eosinophil ratio > 13.0 (AUC 0.7814), neutrophil/lymphocyte ratio > 7.5 (AUC 0.7784), eosinophil count < 1.1 × 109/L (AUC 0.7780), and neutrophil/albumin × 10 > 2.4 (AUC 0.7732); additionally, sensitivity was 83.1-75.4% and specificity was 82.1-75.0%. The highest predictors of in-hospital death were platelet/lymphocyte ratio > 280.0 (AUC 0.8390), lymphocyte/monocyte ratio < 1.1 (AUC 0.8375), albumin < 33 g/L (AUC 0.7889), red cell distribution width > 14.5% (AUC 0.7739), and anaemia (AUC 0.7604), sensitivity 88.2% and above, and specificity 85.1-79.3%. Internal validation confirmed the predictive value of the models. Conclusions: Comparison of 27 IIM indices in HF patients identified several simple, widely available, and inexpensive parameters highly predictive for PMI and/or in-hospital death. The applicability of IIM biomarkers to diagnose and predict risks for chronic diseases, including OP/OF, in the preclinical stages is discussed.

Associations between special diet and incidence risk of osteoporosis: a Mendelian randomization study

Introduction

Osteoporosis is a prevalent challenge in clinical orthopedics, affecting a significant percentage of individuals aged 50 and above. The goal of this study was to comprehensively understand the relationships between a specialized dietary regimen and the risk of developing osteoporosis.

Methods

This study employed extensive genome-wide association study (GWAS) summary statistics derived from the UK Biobank. It encompassed 8 kinds of special diets and 7 datasets pertaining to osteoporosis and associated symptoms. The principal analytical approach employed was the inverse-variance weighted method. Additionally, sensitivity analysis was employed to elucidate the diverse multiplicity patterns observed in the final model.

Results

Our results showed that there is significant evidence that a gluten-free diet is associated with osteoporosis [odds ratio (OR): 1.080, 95% confidence interval (CI): 1.048-1.112, p = 4.23E-07)]. Furthermore, there exists a suggestive link between the three distinct dietary approaches and osteoporosis [(OR: 0.949, 95%CI: 0.929-0.970, p = 3.00E-06) for comprehensive consumption; (OR: 1.053, 95%CI: 1.018-1.089, p = 2.23E-03) for abstaining from wheat consumption; (OR: 1.036, 95%CI: 1.005-1.068, p = 1.97E-02) for abstaining from sugar consumption]. No additional correlation between the special dietary regimens and osteoporosis has been observed.

Conclusion

Our research has uncovered a notable correlation between a gluten-free diet and the occurrence of osteoporosis. Furthermore, it exerts a promoting influence on the onset of osteoporosis, which stands in direct contradiction to the therapeutic principles for Celiac Disease's complications. As such, a novel association among these three elements is postulated.

Diets intervene osteoporosis via gut-bone axis

Osteoporosis is a systemic skeletal disease that seriously endangers the health of middle-aged and older adults. Recently, with the continuous deepening of research, an increasing number of studies have revealed gut microbiota as a potential target for osteoporosis, and the research concept of the gut-bone axis has gradually emerged. Additionally, the intake of dietary nutrients and the adoption of dietary patterns may affect the gut microbiota, and alterations in the gut microbiota might also influence the metabolic status of the host, thus adjusting bone metabolism. Based on the gut-bone axis, dietary intake can also participate in the modulation of bone metabolism by altering abundance, diversity, and composition of gut microbiota. Herein, combined with emerging literatures and relevant studies, this review is aimed to summarize the impacts of different dietary components and patterns on osteoporosis by acting on gut microbiota, as well as underlying mechanisms and proper dietary recommendations.