Track topics on Twitter Track topics that are important to you
Gut microbiota regulate metabolism of their human host. Some diseases are associated with variations in gut microbiota diversity and higher fracture risk. Intestinal bacteria synthesize or influence synthesis of factors modulating bone metabolism. The link between gut microbiota and bone was assessed mainly in experimental animal studies. Clinical data, e.g. on the role of gut microbiota in postmenopausal osteoporosis are scarce. The investigators will compare gut microbiota composition in four groups of women aged ≥60 recruited on the basis of bone mineral density (BMD) and personal history of fracture. the participants will have diagnostic exams: clinical tests, bone densitometry (body composition, vertebral fractures), high resolution peripheral QCT (bone strength estimated by microfinite element analysis, micro-FEA), biological sample collection. Gut microbiome profiling will be performed at the INRA MetaGenoPolis laboratory. The investigators will compare gut microbiota diversity according to BMD level and to the fracture status. The investigators will analyze interactions of the gut microbiota diversity with bone status (bone turnover rate, BMD, bone microarchitecture, bone strength estimated by micro-FEA), muscle mass and strength, inflammatory cytokines and micro-RNAs modulating their expression. This study will provide new data concerning the importance of gut microbiota for the fracture risk in older women. It will help to identify the main metabolic pathways underlying the observed associations.
Postmenopausal osteoporosis is a major public health problem in developed countries. Despite the progress, knowledge of its pathophysiological mechanisms and identification of women at high risk of fracture in the clinical practice are not satisfactory. Gut microbiota consist of trillions of commensal bacteria playing a major role in the regulation of metabolism of their human host. Some conditions (diabetes mellitus, obesity, liver cirrhosis, inflammatory bowel disease, end stage renal disease, depression, heavy drinking, heavy smoking) are associated with variations in gut microbiota diversity and higher risk of fracture. Intestinal bacteria synthesize or influence the synthesis of factors which modulate bone metabolism, e.g. lipopolysaccharide (present in the wall of Gram-negative bacteria), inflammatory cytokines (synthesized in the gut associated lymphoid tissue), serotonin (synthesized in the colon epithelium), short-chain fatty acids, estrogens (deconjugation of sulphates and glucuronides). Data on the association between gut microbiota and bone metabolism were obtained mainly in experimental animal studies. Clinical data are limited. Data on the possible role of gut microbiota in the pathophysiology of the postmenopausal osteoporosis are scarce.
The investigators will carry out a cross-sectional comparison of gut microbiota composition in four groups of women aged 60 and over recruited on the basis of their bone mineral density (BMD) and personal history of fragility fracture. The primary statistical analyses will be focused on the comparison of gut microbiota diversity according to BMD (in women with the same fracture status) and according to the fracture status (in women with similar BMD). The investigators will analyze interactions of the gut microbiota diversity, its metabolic activity and other metabolic factors on the one hand, with bone status on the other hand. The investigators will study the association of gut microbiota composition with bone turnover rate, BMD, bone microarchitecture, bone strength estimated by microfinite element analysis (micro-FEA) and with physical performance, muscle mass and strength. The investigators will assess the impact of microRNAs modulating the expression of inflammatory cytokines on the serum levels of these cytokines according to the pattern of gut microbiota diversity and their associations with the characteristics of bone status (e.g. bone microarchitecture). The investigators will analyze the association between serum serotonin, abundance of intestinal bacteria stimulating serotonin synthesis (some Clostridia species) in the colon and the characteristics of bone status.
This study will provide new data concerning the importance of gut microbiota for the fracture risk in older women. The main limitation of this study is its cross-sectional design but this is the first clinical study exploring this subject. It will help to identify the main metabolic pathways underlying the observed associations. These data will stimulate experimental studies to elucidate biological mechanisms underlying these associations. the results will provide indications for future clinical and experimental studies. In the long run, the results will lead up to future studies permitting to develop new biological markers of fracture risk in older women and new anti-osteoporotic medications.
Bone Loss, Age-related
bone densitometry, High resolution peripheral QCT, Collection of biological samples, questionnaires, clinical tests
Hopital E. Herriot
Institut National de la Santé Et de la Recherche Médicale, France
Published on BioPortfolio: 2020-02-16T17:40:49-0500
Based on the evidence that periostin is specifically involved in intra-cortical remodeling control, our working hypothesis is that assessment of its concentration in the serum would be hel...
Optimal surgical therapy (debridement in chronic osteomyelitis; device exchange in patients with chronic prosthetic joint infection (PJI)) could be sometimes non-feasible, especially in th...
Consitution Of A Biological Collection From Samples From The Gut Microbiote In Patients Having A Bone Or Joint Infection Treated By A Suppressive Subcutaneous Antibiotherapy With BetalactamineHabing A Bone Or Joint Infection Treated by A Suppressive Subcu
Optimal surgical therapy (debridement in chronic osteomyelitis; device exchange in patients with chronic prosthetic joint infection [PJI]) could be sometimes non-feasible, especially in th...
Patients with cystic fibrosis are at risk of developing low bone mineral density (BMD) potentially leading to pathological fractures at adult age. Recent data from our center and others ha...
Patients with Rheumatoid Arthritis (RA) suffer systemic and peripheral bone loss. In this study we aim to test the efficacy of in-label treatment with Baricitinib on the volumetric bone mi...
Subchondral bone plays an important role in the pathological mechanisms of knee osteoarthritis (OA). High-resolution peripheral quantitative computed tomography (HR-pQCT) is an imaging modality allowi...
High-resolution peripheral quantitative computed tomography (HR-pQCT) has enabled us to observe changes of bone microstructure during fracture healing. However, a method of analyzing the healing proce...
Nanometre-scale observation of specimens in water is indispensable in several scientific fields, such as biology, chemistry, materials science and nanotechnology. Scanning electron microscopy (SEM) ob...
Blood samples are the most common and important biological samples found at crime scenes, and distinguishing peripheral blood and menstrual blood samples is crucial for solving criminal cases. MicroRN...
The last two decades have seen growing recognition of the need to appropriately identify and treat children with osteoporotic fractures. This focus stems from important advances in our understanding o...
Type of microscopy used to study biological systems at high resolution.
The process of protecting various samples of biological material.
Development of a library collection, including the determination and coordination of selection policy, assessment of needs of users and potential users, collection use studies, collection evaluation, identification of collection needs, selection of materials, planning for resource sharing, collection maintenance and weeding, and budgeting.
Methods or procedures used to obtain samples of URINE.
Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.
Osteoporosis is a disease in which the bones become extremely porous, are subject to fracture, and heal slowly, occurring especially in women following menopause and often leading to curvature of the spine from vertebral collapse. Follow and track&n...
Arthritis Fibromyalgia Gout Lupus Rheumatic Rheumatology is the medical specialty concerned with the diagnosis and management of disease involving joints, tendons, muscles, ligaments and associated structures (Oxford Medical Diction...