Both Disease Activity and HLA-B27 Status Are Associated With Gut Microbiome Dysbiosis in Spondyloarthritis Patients.

Objective: Gut microbiome dysbiosis has previously been reported in spondyloarthritis (SpA) patients and could be critically involved in the pathogenesis of this disorder. The objectives of this study were to further characterize the microbiota structure in SpA patients and to investigate the relationship between dysbiosis and disease activity in light of the putative influence of the genetic background.

Methods: Shotgun sequencing was performed on fecal DNA isolated from stool samples from 2 groups of adult volunteers: SpA patients (n = 102) and healthy controls (n = 63).

Faecal microbiota study reveals specific dysbiosis in spondyloarthritis.

Objective: Altered microbiota composition or dysbiosis is suspected to be implicated in the pathogenesis of chronic inflammatory diseases, such as spondyloarthritis (SpA) and rheumatoid arthritis (RA).

Methods: 16S ribosomal RNA gene sequencing was performed on faecal DNA isolated from stool samples in two consecutive cross-sectional cohorts, each comprising three groups of adult volunteers: SpA, RA and healthy controls (HCs). In the second study, HCs comprised a majority of aged-matched siblings of patients with known HLA-B27 status.

Gut microbiota richness promotes its stability upon increased dietary fibre intake in healthy adults.

Gut microbiota richness and stability are important parameters in host-microbe symbiosis. Diet modification, notably using dietary fibres, might be a way to restore a high richness and stability in the gut microbiota. In this work, during a 6-week nutritional trial, 19 healthy adults consumed a basal diet supplemented with 10 or 40 g dietary fibre per day for 5 days, followed by 15-day washout periods.

The detection of the methylated Wif-1 gene is more accurate than a fecal occult blood test for colorectal cancer screening.

Background: The clinical benefit of guaiac fecal occult blood tests (FOBT) is now well established for colorectal cancer screening. Growing evidence has demonstrated that epigenetic modifications and fecal microbiota changes, also known as dysbiosis, are associated with CRC pathogenesis and might be used as surrogate markers of CRC.

Patients And Methods: We performed a cross-sectional study that included all consecutive subjects that were referred (from 2003 to 2007) for screening colonoscopies.

Oil composition of high-fat diet affects metabolic inflammation differently in connection with endotoxin receptors in mice.

Low-grade inflammation observed in obesity is a risk factor for cardiovascular disease. Recent studies revealed that this would be linked to gut-derived endotoxemia during fat digestion in high-fat diets, but nothing is known about the effect of lipid composition. The study was designed to test the impact of oil composition of high-fat diets on endotoxin metabolism and inflammation in mice.

Microbial dysbiosis in colorectal cancer (CRC) patients.

Unlabelled: The composition of the human intestinal microbiota is linked to health status. The aim was to analyze the microbiota of normal and colon cancer patients in order to establish cancer-related dysbiosis.

Patients And Methods: Stool bacterial DNA was extracted prior to colonoscopy from 179 patients: 60 with colorectal cancer, and 119 with normal colonoscopy.

Differential adaptation of human gut microbiota to bariatric surgery-induced weight loss: links with metabolic and low-grade inflammation markers.

Objective: Obesity alters gut microbiota ecology and associates with low-grade inflammation in humans. Roux-en-Y gastric bypass (RYGB) surgery is one of the most efficient procedures for the treatment of morbid obesity resulting in drastic weight loss and improvement of metabolic and inflammatory status. We analyzed the impact of RYGB on the modifications of gut microbiota and examined links with adaptations associated with this procedure.

Highlighting new phylogenetic specificities of Crohn's disease microbiota.

Background: Recent studies suggest that gastrointestinal (GI) microbes play a part in the pathogenesis of Crohn's disease (CD).

Methods: Fecal samples were collected from 16 healthy individuals and 16 CD patients (age- and sex-matched). The DNA extracted from these samples were subjected to two different methods of microbiome analysis.

Towards the human intestinal microbiota phylogenetic core.

The paradox of a host specificity of the human faecal microbiota otherwise acknowledged as characterized by global functionalities conserved between humans led us to explore the existence of a phylogenetic core. We investigated the presence of a set of bacterial molecular species that would be altogether dominant and prevalent within the faecal microbiota of healthy humans. A total of 10 456 non-chimeric bacterial 16S rRNA sequences were obtained after cloning of PCR-amplified rDNA from 17 human faecal DNA samples.

The Firmicutes/Bacteroidetes ratio of the human microbiota changes with age.

Background: In humans, the intestinal microbiota plays an important role in the maintenance of host health by providing energy, nutrients, and immunological protection. Applying current molecular methods is necessary to surmount the limitations of classical culturing techniques in order to obtain an accurate description of the microbiota composition.

Results: Here we report on the comparative assessment of human fecal microbiota from three age-groups: infants, adults and the elderly.

Estimation of pig fecal contamination in a river catchment by real-time PCR using two pig-specific Bacteroidales 16S rRNA genetic markers.

The microbiological quality of coastal or river water can be affected by fecal contamination from human or animal sources. To discriminate pig fecal pollution from other pollution, a library-independent microbial source tracking method targeting Bacteroidales host-specific 16S rRNA gene markers by real-time PCR was designed. Two pig-specific Bacteroidales markers (Pig-1-Bac and Pig-2-Bac) were designed using 16S rRNA gene Bacteroidales clone libraries from pig feces and slurry.

Comparative assessment of human and farm animal faecal microbiota using real-time quantitative PCR.

Pollution of the environment by human and animal faecal pollution affects the safety of shellfish, drinking water and recreational beaches. To pinpoint the origin of contaminations, it is essential to define the differences between human microbiota and that of farm animals. A strategy based on real-time quantitative PCR (qPCR) assays was therefore developed and applied to compare the composition of intestinal microbiota of these two groups.

Low counts of Faecalibacterium prausnitzii in colitis microbiota.

Background: The intestinal microbiota is suspected to play a role in colitis and particularly in inflammatory bowel disease (IBD) pathogenesis. The aim was to compare the fecal microbiota composition of patients with colitis to that of healthy subjects (HS).

Methods: fecal samples from 22 active Crohn's disease (A-CD) patients, 10 CD patients in remission (R-CD), 13 active ulcerative colitis (A-UC) patients, 4 UC patients in remission (R-UC), 8 infectious colitis (IC) patients, and 27 HS were analyzed by quantitative real-time polymerase chain reaction (PCR) targeting the 16S rRNA gene.

Faecalibacterium prausnitzii is an anti-inflammatory commensal bacterium identified by gut microbiota analysis of Crohn disease patients.

A decrease in the abundance and biodiversity of intestinal bacteria within the dominant phylum Firmicutes has been observed repeatedly in Crohn disease (CD) patients. In this study, we determined the composition of the mucosa-associated microbiota of CD patients at the time of surgical resection and 6 months later using FISH analysis. We found that a reduction of a major member of Firmicutes, Faecalibacterium prausnitzii, is associated with a higher risk of postoperative recurrence of ileal CD.

Fate and effects of Camembert cheese micro-organisms in the human colonic microbiota of healthy volunteers after regular Camembert consumption.

The objective of this study was to determine i) if Camembert cheese micro-organisms could be detected in fecal samples after regular consumption by human subjects and ii) the consequence of this consumption on global metabolic activities of the host colonic microbiota. An open human protocol was designed where 12 healthy volunteers were included: a 2-week period of fermented products exclusion followed by a 4-weeks Camembert ingestion period where 2x40 g/day of Camembert cheese was consumed. Stools were collected from the volunteers before consumption, twice during the ingestion period (2nd and 4th week) and once after a wash out period of 2 weeks.

Lactobacillus rhamnosus R11 consumed in a food supplement survived human digestive transit without modifying microbiota equilibrium as assessed by real-time polymerase chain reaction.

The aim of this study was to evaluate the survival of Lactobacillus rhamnosus R11 and Lactobacillus acidophilus R52 in the human digestive tract and their effects on the microbiota homeostasis. We designed an open human trial including 14 healthy volunteers. A 3-week exclusion period of fermented products was followed by a 12-day consumption period of 4 capsules daily containing 2 x 10(9)L.

Consumption of Camembert cheese stimulates commensal enterococci in healthy human intestinal microbiota.

Enterococci are natural inhabitants of the human gastrointestinal tract and the main Gram-positive and facultative anaerobic cocci recovered in human faeces. They are also present in a variety of fermented dairy and meat products, and some rare isolates are responsible for severe infections such as endocarditis and meningitis. The aim of the present study was to evaluate the effect of Camembert cheese consumption by healthy human volunteers on the faecal enterococcal population.

Quantitative effects of an intronic retroviral insertion on the transcription of the tyrosinase gene in recessive white chickens.

Recently, we reported the complete association of a retroviral insertion in intron 4 of the tyrosinase gene and the recessive white mutation (c) in chickens. The mutant allele carrying the retroviral insertion produced, in skin samples of 10-week-old chickens, aberrant tyrosinase transcripts that did not contain exon 5. In the present study, we performed serial molecular and statistical analyses on embryos and 10-week-old chickens to characterize the quantitative effect of the retroviral insertion on the expression pattern of tyrosinase in different tissues (skin and retina).

Effects of orally administered Lactobacillus casei DN-114 001 on the composition or activities of the dominant faecal microbiota in healthy humans.

The composition and activities of the faecal microbiota in twelve healthy subjects analysed in a single open study were monitored before (1-week baseline step), during (10 d supplementation step) and after (10 d follow-up step) the ingestion of a fermented milk containing Lactobacillus casei DN-114 001. Fluorescent in situ hybridisation with group-specific DNA probes, real-time PCR using L. paracasei group-specific primers and temporal temperature gradient gel electrophoresis (TTGE) using group-specific primers were carried out, together with bacterial enzyme activity and metabolite analyses to monitor the structure and activities of the faecal microbiota.

1H nuclear magnetic resonance spectroscopy-based studies of the metabolism of food-borne carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline by human intestinal microbiota.

2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) is a mutagenic/carcinogenic compound formed from meat and fish during cooking. Following ingestion, IQ is metabolized mainly by liver xenobiotic-metabolizing enzymes, but intestinal bacteria may also contribute to its biotransformation. The aim of this study was to investigate the metabolism of IQ by the human intestinal microbiota.

Differential activities of four Lactobacillus casei promoters during bacterial transit through the gastrointestinal tracts of human-microbiota-associated mice.

In a previous study using fusion of the deregulated lactose promoter lacTp* and reporter genes, we suggested that Lactobacillus casei could initiate de novo protein synthesis during intestinal transit. In order to confirm this finding and extend it to other promoters, we adopted a reverse transcriptase quantitative PCR (RT-QPCR) approach combined with a transcriptional fusion system consisting of luciferase genes under the control of four promoters (ccpA, dlt, ldh, and lacT*) from L. casei DN-114 001.

Molecular quantification of lactic acid bacteria in fermented milk products using real-time quantitative PCR.

Real-time quantitative PCR assays were developed for the absolute quantification of lactic acid bacteria (LAB) (Streptococcus thermophilus, Lactobacillus delbrueckii, L. casei, L. paracasei, L.

Docosahexaenoic acid membrane content and mRNA expression of acyl-CoA oxidase and of peroxisome proliferator-activated receptor-delta are modulated in Y79 retinoblastoma cells differently by low and high doses of alpha-linolenic acid.

The mRNA expression levels of acyl-CoA oxidase (AOX), a key enzyme in very-long-chain fatty acid peroxisomal oxidation, and of peroxisome proliferator-activated receptor-delta (PPAR-delta), a nuclear receptor possibly involved in the gene regulation of brain lipid metabolism, were determined in human Y79 retinoblastoma cells by using real-time quantitative polymerase chain reaction. Cells were dosed with alpha-linolenic acid (18:3n-3), the essential metabolic precursor of the n-3 polyunsaturated fatty acid series that normally gives rise through terminal peroxisomal oxidation to the synthesis of membrane docosahexaenoic acid (22:6n-3, or DHA). The AOX and PPAR-delta relative expression levels increased 2.

A 11.7-kb deletion triggers intersexuality and polledness in goats.

Mammalian sex determination is governed by the presence of the sex determining region Y gene (SRY) on the Y chromosome. Familial cases of SRY-negative XX sex reversal are rare in humans, often hampering the discovery of new sex-determining genes. The mouse model is also insufficient to correctly apprehend the sex-determination cascade, as the human pathway is much more sensitive to gene dosage.

Fine mapping suggests that the goat Polled Intersex Syndrome and the human Blepharophimosis Ptosis Epicanthus Syndrome map to a 100-kb homologous region.

To clone the goat Polled Intersex Syndrome (PIS) gene(s), a chromosome walk was performed from six entry points at 1q43. This enabled 91 BACs to be recovered from a recently constructed goat BAC library. Six BAC contigs of goat chromosome 1q43 (ICC1-ICC6) were thus constructed covering altogether 4.