34 research outputs found

    The gut microbiota in multiple sclerosis varies with disease activity

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    BACKGROUND: Multiple sclerosis is a chronic immune-mediated disease of the brain and spinal cord resulting in physical and cognitive impairment in young adults. It is hypothesized that a disrupted bacterial and viral gut microbiota is a part of the pathogenesis mediating disease impact through an altered gut microbiota-brain axis. The aim of this study is to explore the characteristics of gut microbiota in multiple sclerosis and to associate it with disease variables, as the etiology of the disease remains only partially known. METHODS: Here, in a case-control setting involving 148 Danish cases with multiple sclerosis and 148 matched healthy control subjects, we performed shotgun sequencing of fecal microbial DNA and associated bacterial and viral microbiota findings with plasma cytokines, blood cell gene expression profiles, and disease activity. RESULTS: We found 61 bacterial species that were differentially abundant when comparing all multiple sclerosis cases with healthy controls, among which 31 species were enriched in cases. A cluster of inflammation markers composed of blood leukocytes, CRP, and blood cell gene expression of IL17A and IL6 was positively associated with a cluster of multiple sclerosis-related species. Bacterial species that were more abundant in cases with disease-active treatment-naĂŻve multiple sclerosis were positively linked to a group of plasma cytokines including IL-22, IL-17A, IFN-ÎČ, IL-33, and TNF-α. The bacterial species richness of treatment-naĂŻve multiple sclerosis cases was associated with number of relapses over a follow-up period of 2 years. However, in non-disease-active cases, we identified two bacterial species, Faecalibacterium prausnitzii and Gordonibacter urolithinfaciens, whose absolute abundance was enriched. These bacteria are known to produce anti-inflammatory metabolites including butyrate and urolithin. In addition, cases with multiple sclerosis had a higher viral species diversity and a higher abundance of Caudovirales bacteriophages. CONCLUSIONS: Considerable aberrations are present in the gut microbiota of patients with multiple sclerosis that are directly associated with blood biomarkers of inflammation, and in treatment-naĂŻve cases bacterial richness is positively associated with disease activity. Yet, the finding of two symbiotic bacterial species in non-disease-active cases that produce favorable immune-modulating compounds provides a rationale for testing these bacteria as adjunct therapeutics in future clinical trials

    Impairment of gut microbial biotin metabolism and host biotin status in severe obesity: effect of biotin and prebiotic supplementation on improved metabolism

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    Objectives Gut microbiota is a key component in obesity and type 2 diabetes, yet mechanisms and metabolites central to this interaction remain unclear. We examined the human gut microbiome\u27s functional composition in healthy metabolic state and the most severe states of obesity and type 2 diabetes within the MetaCardis cohort. We focused on the role of B vitamins and B7/B8 biotin for regulation of host metabolic state, as these vitamins influence both microbial function and host metabolism and inflammation. Design We performed metagenomic analyses in 1545 subjects from the MetaCardis cohorts and different murine experiments, including germ-free and antibiotic treated animals, faecal microbiota transfer, bariatric surgery and supplementation with biotin and prebiotics in mice. Results Severe obesity is associated with an absolute deficiency in bacterial biotin producers and transporters, whose abundances correlate with host metabolic and inflammatory phenotypes. We found suboptimal circulating biotin levels in severe obesity and altered expression of biotin-associated genes in human adipose tissue. In mice, the absence or depletion of gut microbiota by antibiotics confirmed the microbial contribution to host biotin levels. Bariatric surgery, which improves metabolism and inflammation, associates with increased bacterial biotin producers and improved host systemic biotin in humans and mice. Finally, supplementing high-fat diet-fed mice with fructo-oligosaccharides and biotin improves not only the microbiome diversity, but also the potential of bacterial production of biotin and B vitamins, while limiting weight gain and glycaemic deterioration. Conclusion Strategies combining biotin and prebiotic supplementation could help prevent the deterioration of metabolic states in severe obesity

    Imidazole propionate is increased in diabetes and associated with dietary patterns and altered microbial ecology

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    Microbiota-host-diet interactions contribute to the development of metabolic diseases. Imidazole propionate is a novel microbially produced metabolite from histidine, which impairs glucose metabolism. Here, we show that subjects with prediabetes and diabetes in the MetaCardis cohort from three European countries have elevated serum imidazole propionate levels. Furthermore, imidazole propionate levels were increased in subjects with low bacterial gene richness and Bacteroides 2 enterotype, which have previously been associated with obesity. The Bacteroides 2 enterotype was also associated with increased abundance of the genes involved in imidazole propionate biosynthesis from dietary histidine. Since patients and controls did not differ in their histidine dietary intake, the elevated levels of imidazole propionate in type 2 diabetes likely reflects altered microbial metabolism of histidine, rather than histidine intake per se. Thus the microbiota may contribute to type 2 diabetes by generating imidazole propionate that can modulate host inflammation and metabolism

    Imidazole propionate is increased in diabetes and associated with dietary patterns and altered microbial ecology

    Get PDF
    Microbiota-host-diet interactions contribute to the development of metabolic diseases. Imidazole propionate is a novel microbially produced metabolite from histidine, which impairs glucose metabolism. Here, we show that subjects with prediabetes and diabetes in the MetaCardis cohort from three European countries have elevated serum imidazole propionate levels. Furthermore, imidazole propionate levels were increased in subjects with low bacterial gene richness and Bacteroides 2 enterotype, which have previously been associated with obesity. The Bacteroides 2 enterotype was also associated with increased abundance of the genes involved in imidazole propionate biosynthesis from dietary histidine. Since patients and controls did not differ in their histidine dietary intake, the elevated levels of imidazole propionate in type 2 diabetes likely reflects altered microbial metabolism of histidine, rather than histidine intake per se. Thus the microbiota may contribute to type 2 diabetes by generating imidazole propionate that can modulate host inflammation and metabolism

    Rare pathogenic variants in WNK3 cause X-linked intellectual disability

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordData availability: All data are available upon request. The sequence variants in WNK3 (NM_004656.3) reported in the paper have been deposited in ClinVar database. Their respective accession numbers (SCV002107163 to SCV002107168) are indicated in Tables 1 and S1.Purpose WNK3 kinase (PRKWNK3) has been implicated in the development and function of the brain via its regulation of the cation-chloride cotransporters, but the role of WNK3 in human development is unknown. Method We ascertained exome or genome sequences of individuals with rare familial or sporadic forms of intellectual disability (ID). Results We identified a total of 6 different maternally-inherited, hemizygous, 3 loss-of-function or 3 pathogenic missense variants (p.Pro204Arg, p.Leu300Ser, p.Glu607Val) in WNK3 in 14 male individuals from 6 unrelated families. Affected individuals had identifier with variable presence of epilepsy and structural brain defects. WNK3 variants cosegregated with the disease in 3 different families with multiple affected individuals. This included 1 large family previously diagnosed with X-linked Prieto syndrome. WNK3 pathogenic missense variants localize to the catalytic domain and impede the inhibitory phosphorylation of the neuronal-specific chloride cotransporter KCC2 at threonine 1007, a site critically regulated during the development of synaptic inhibition. Conclusion Pathogenic WNK3 variants cause a rare form of human X-linked identifier with variable epilepsy and structural brain abnormalities and implicate impaired phospho-regulation of KCC2 as a pathogenic mechanism.Estonian Research CouncilNational Natural Science Foundation of ChinaRoyal SocietySouth Carolina Department of Disabilities and Special Needs (SCDDSN)National Institute of Neurological Disorders and Stroke (NINDS
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