A gluten-free diet (GFD) is the most commonly adopted special diet worldwide. It is an effective treatment for coeliac disease and is also often followed by individuals to alleviate gastrointestinal ...complaints. It is known there is an important link between diet and the gut microbiome, but it is largely unknown how a switch to a GFD affects the human gut microbiome.
We studied changes in the gut microbiomes of 21 healthy volunteers who followed a GFD for four weeks. We collected nine stool samples from each participant: one at baseline, four during the GFD period, and four when they returned to their habitual diet (HD), making a total of 189 samples. We determined microbiome profiles using 16S rRNA sequencing and then processed the samples for taxonomic and imputed functional composition. Additionally, in all 189 samples, six gut health-related biomarkers were measured.
Inter-individual variation in the gut microbiota remained stable during this short-term GFD intervention. A number of taxon-specific differences were seen during the GFD: the most striking shift was seen for the family Veillonellaceae (class Clostridia), which was significantly reduced during the intervention (p = 2.81 × 10(-05)). Seven other taxa also showed significant changes; the majority of them are known to play a role in starch metabolism. We saw stronger differences in pathway activities: 21 predicted pathway activity scores showed significant association to the change in diet. We observed strong relations between the predicted activity of pathways and biomarker measurements.
A GFD changes the gut microbiome composition and alters the activity of microbial pathways.
Gut Microbiota and Risk of Developing Celiac Disease Cenit, Maria C; Codoñer-Franch, Pilar; Sanz, Yolanda
Journal of clinical gastroenterology,
2016-November/December, Letnik:
50 Suppl 2, Proceedings from the 8th Probiotics, Prebiotics & New Foods for Microbiota and Human Health meeting held in Rome, Italy on September 13–15, 2015, Številka:
Supplement 2
Journal Article
Recenzirano
Gut microbiota shapes the development of the mucosal immune system and may provide protection against immune-mediated diseases. Celiac disease (CD) is a chronic inflammatory condition triggered by ...dietary gluten proteins, recently associated with gut microbiota alterations in cross-sectional studies comparing patients and controls. Whether or not these differences are causally related to the disease has yet to be elucidated, but evaluation of specific bacteria isolated from CD patients in experimental models suggests that they can promote an adverse response to dietary gluten, whereas other commensal bacteria can be protective. Genetic and environmental factors associated with increased CD risk have also been linked to shifts in the gut microbiota composition in infants early in life. Epigenetic mechanisms also seem to play an important role in modulating gut microbiota composition and function and, theoretically, could also influence CD risk. Here, we review the current knowledge on how host genetics, environmental factors, and epigenetic modifications could modulate gut microbiota functionality and how this may influence CD risk. Greater understanding of the role of this triad in CD onset and pathogenesis will be valuable in designing proof-of concept interventions in the gut ecosystem, with a view to improving CD management.
It is increasingly evident that perturbations to the diversity and composition of the gut microbiota have significant consequences for the regulation of integrative physiological systems. There is ...growing interest in the potential contribution of microbiota-gut-brain signalling to cardiorespiratory control in health and disease.
In adult male rats, we sought to determine the cardiorespiratory effects of manipulation of the gut microbiota following a 4-week administration of a cocktail of antibiotics. We subsequently explored the effects of administration of faecal microbiota from pooled control (vehicle) rat faeces, given by gavage to vehicle- and antibiotic-treated rats.
Antibiotic intervention depressed the ventilatory response to hypercapnic stress in conscious animals, owing to a reduction in the respiratory frequency response to carbon dioxide. Baseline frequency, respiratory timing variability, and the expression of apnoeas and sighs were normal. Microbiota-depleted rats had decreased systolic blood pressure. Faecal microbiota transfer to vehicle- and antibiotic-treated animals also disrupted the gut microbiota composition, associated with depressed ventilatory responsiveness to hypercapnia. Chronic antibiotic intervention or faecal microbiota transfer both caused significant disruptions to brainstem monoamine neurochemistry, with increased homovanillic acid:dopamine ratio indicative of increased dopamine turnover, which correlated with the abundance of several bacteria of six different phyla.
Chronic antibiotic administration and faecal microbiota transfer disrupt gut microbiota, brainstem monoamine concentrations and the ventilatory response to hypercapnia. We suggest that aberrant microbiota-gut-brain axis signalling has a modulatory influence on respiratory behaviour during hypercapnic stress.
Department of Physiology and APC Microbiome Ireland, University College Cork, Ireland.
Abstract A recent meta-analysis of genome-wide association screens coupled to a replication exercise in a combined US/UK collection led to the identification of 4 single nucleotide polymorphisms ...(SNPs) in three gene loci, i.e. TNFRSF1A , CD6 and IRF8 , as novel risk factors for multiple sclerosis with genome-wide level of significance. In the present study, using a combined all-Spain collection of 2515 MS patients and 2942 healthy controls, we demonstrate significant association of rs17824933 in CD6 ( P CMH = 0.004; OR = 1.14; 95% CI 1.04–1.24) and of rs1860545 in TNFRSF1A ( P CMH = 0.001; OR = 1.15; 95% CI 1.06–1.25) with MS, while the low-frequency coding non-synonymous SNP rs4149584 in TNFRSF1A displayed a trend for association ( P CMH = 0.062; OR = 1.27; 95% CI 0.99–1.63). This data reinforce a generic role for CD6 and TNFRSF1A in susceptibility to MS, extending to populations of southern European ancestry.
Background: It is increasingly evident that perturbations to the diversity and composition of the gut microbiota have significant consequences for the regulation of integrative physiological systems. ...There is growing interest in the potential contribution of microbiota-gut-brain signalling to cardiorespiratory control in health and disease. Methods: In adult male rats, we sought to determine the cardiorespiratory effects of manipulation of the gut microbiota following a 4-week administration of a cocktail of antibiotics. We subsequently explored the effects of administration of faecal microbiota from pooled control (vehicle) rat faeces, given by gavage to vehicle- and antibiotic-treated rats. Findings: Antibiotic intervention depressed the ventilatory response to hypercapnic stress in conscious animals, owing to a reduction in the respiratory frequency response to carbon dioxide. Baseline frequency, respiratory timing variability, and the expression of apnoeas and sighs were normal. Microbiota-depleted rats had decreased systolic blood pressure. Faecal microbiota transfer to vehicle- and antibiotic-treated animals also disrupted the gut microbiota composition, associated with depressed ventilatory responsiveness to hypercapnia. Chronic antibiotic intervention or faecal microbiota transfer both caused significant disruptions to brainstem monoamine neurochemistry, with increased homovanillic acid:dopamine ratio indicative of increased dopamine turnover, which correlated with the abundance of several bacteria of six different phyla. Interpretation: Chronic antibiotic administration and faecal microbiota transfer disrupt gut microbiota, brainstem monoamine concentrations and the ventilatory response to hypercapnia. We suggest that aberrant microbiota-gut-brain axis signalling has a modulatory influence on respiratory behaviour during hypercapnic stress. Fund: Department of Physiology and APC Microbiome Ireland, University College Cork, Ireland. Keywords: Antibiotics, Faecal microbiota transfer, Breathing, Hypercapnia, Cardiovascular, Vagus, Neurochemistry, Intestinal permeability, Microbiota
Multiple sclerosis (MS) is a multifactorial disease with a genetic basis. The strongest associations with the disease lie in the Human Leukocyte Antigen (HLA) region. However, except for the ...DRB1*15:01 allele, the main risk factor associated to MS so far, no consistent effect has been described for any other variant. One example is HLA-DRB1*03:01, with a heterogeneous effect across populations and studies. We postulate that those discrepancies could be due to differences in the diverse haplotypes bearing that allele. Thus, we aimed at studying the association of DRB1*03:01 with MS susceptibility considering this allele globally and stratified by haplotypes. We also evaluated the association with the presence of oligoclonal IgM bands against myelin lipids (OCMB) in cerebrospinal fluid.
Genotyping of HLA-B, -DRB1 and -DQA1 was performed in 1068 MS patients and 624 ethnically matched healthy controls. One hundred and thirty-nine MS patients were classified according to the presence (M+, 58 patients)/absence (M-, 81 patients) of OCMB. Comparisons between groups (MS patients vs. controls and M+ vs. M-) were performed with the chi-square test or the Fisher exact test.
Association of DRB1*03:01 with MS susceptibility was observed but with different haplotypic contribution, being the ancestral haplotype (AH) 18.2 the one causing the highest risk. Comparisons between M+, M- and controls showed that the AH 18.2 was affecting only M+ individuals, conferring a risk similar to that caused by DRB1*15:01.
The diverse DRB1*03:01-containing haplotypes contribute with different risk to MS susceptibility. The AH 18.2 causes the highest risk and affects only to individuals showing OCMB.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Systemic sclerosis (SSc) is a genetically complex autoimmune disease; the genetic component has not been fully defined. Interleukin 6 (IL-6) plays a crucial role in immunity and fibrosis, both key ...aspects of SSc. We investigated the influence of IL6 gene in the susceptibility and phenotype expression of SSc.
We performed a large metaanalysis including a total of 2749 cases and 3189 controls from 6 white populations (Germany, The Netherlands, Norway, Spain, Sweden, and United Kingdom). Three IL6 single-nucleotide polymorphisms (SNP; rs2069827, rs1800795, and rs2069840) were selected by SNP tagging and genotyped using TaqMan(®) allele discrimination technology.
Individual SNP metaanalysis showed no evidence of association of the 3 IL6 genetic variants with the global disease. Phenotype analyses revealed a significant association between the minor allele of rs2069840 and the limited cutaneous SSc clinical form (Bonferroni p = 0.036, OR 1.14, 95% CI 1.04-1.25). A trend of association between the minor allele of the rs1800795 and the diffuse cutaneous SSc clinical form was also evident (Bonferroni p = 0.072, OR 0.86, 95% CI 0.77-0.96). In the IL6 allelic combination analyses, the GGC allelic combination rs2069827-rs1800795-rs2069840 showed an association with overall SSc (Bonferroni p = 0.016, OR 1.13, 95% CI 1.04-1.23).
Our results suggest that the IL6 gene may influence the development of SSc and its progression.
PDF
