Anaerotruncus massiliensis sp. nov., a succinate-producing bacterium isolated from human stool from an obese patient after bariatric surgery.

A new bacterium, strain AT3T, was isolated by microbial culturomics from a faecal sample from a Frenchman after bariatric surgery. The isolate exhibited 96.6% 16S ribosomal RNA gene nucleotide sequence similarity with Anaerotruncus colihominis strain WAL 14565T = CCUG 45055T = CIP 107754T. Phenotypic and genomic characteristics showed that the new strain represents a novel species, for which the name Anaerotruncus massiliensis sp. nov. is proposed. The type strain is strain AT3T = CSUR P2007T = DSM 100567T.

"Ruminococcus phoceensis," a new species identified from human stool from an obese patient before bariatric surgery.

We report here the main characteristics of a new bacterium species, "Ruminococcus phoceensis" strain AT10 (CSUR = P2086, DSM = 100837). This bacterium was isolated from the faeces of a 37-year-old woman from Marseille, France, with morbid obesity before bariatric surgery.

Butyricimonas phoceensis sp. nov., a new anaerobic species isolated from the human gut microbiota of a French morbidly obese patient.

Butyricimonas phoceensis strain AT9 (= CSUR 1981 = DSM 100664) was isolated from a stool sample from a morbidly obese French patient living in Marseille using the culturomics approach. The genome of this Gram-negative-staining, anaerobic and non-spore forming rod bacillus is 4 736 949 bp long and contains 3947 protein-coding genes. Genomic analysis identified 173 genes as ORFans (4.5%) and 1650 orthologous proteins (42%) not shared with the closest phylogenetic species, Butyricimonas virosa. Its major fatty acid was the branched acid iso-C15:0 (62.3%).

'Eisenbergiella massiliensis', a new species isolated from human stool collected after bariatric surgery.

We report the principal characteristics of 'Eisenbergiella massiliensis' sp. nov. strain AT11 (CSURP = P2120, DSM = 101499) that was isolated from a stool sample collected after bariatric surgery of a 56-year-old obese French woman.

Noncontiguous finished genome sequence and description of Paenibacillus ihumii sp. nov. strain AT5.

Paenibacillus ihumii sp. nov. strain AT5 (= CSUR 1981 = DSM 100664) is the type strain of P. ihumii. This bacterium was isolated from a stool sample from a morbidly obese French patient using the culturomics approach. The genome of this Gram-negative, facultative anaerobic, motile and spore-forming bacillus is 5 924 686 bp long. Genomic analysis identified 253 (5%) of 3812 genes as ORFans and at least 2599 (50.03%) of 5194 orthologous proteins not shared with the closest phylogenetic species.

Independent positive association of plasma ß-carotene concentrations with adiponectin among non-diabetic obese subjects.

PURPOSE: Many epidemiological studies find an inverse correlation between carotenoids intake or carotenoids plasma concentrations and body mass index (BMI), insulin resistance or metabolic syndrome in the general population. However, it is not clear whether these relationships occur in obese population. METHODS: We conducted a cross-sectional study in 108 obese non-diabetic patients. RESULTS: There was an inverse correlation between plasma levels of pro-vitamin A carotenoids (α-carotene, ß-carotene and ß-cryptoxanthin) and both BMI and insulin resistance (estimated by the HOMA-IR). No correlation between plasma concentrations of lycopene or lutein/zeaxanthin and BMI or insulin resistance was found. The inverse association between the three pro-vitamin A carotenoids and HOMA-IR disappeared after adjustment for BMI and waist circumference. Interestingly, we identified a positive association between concentrations of ß-carotene and adiponectin in plasma that was independent of sex, age, smoking status, BMI and waist circumference. To our knowledge, such association has never been described in obese patients. CONCLUSION: These results suggest the existence of a favourable effect of ß-carotene on insulin sensitivity in obese individuals that could involve a positive regulation of adiponectin, either directly or via its pro-vitamin A activity. The demonstration of the potential benefits of ß-carotene towards insulin sensitivity would open the way to dietary strategies to prevent metabolic syndrome.

Correlation between body mass index and gut concentrations of Lactobacillus reuteri, Bifidobacterium animalis, Methanobrevibacter smithii and Escherichia coli.

BACKGROUND: Genus and species level analysis is the best way to characterize alterations in the human gut microbiota that are associated with obesity, because the clustering of obese and lean microbiotas increases with the taxonomic depth of the analysis. Bifidobacterium genus members have been associated with a lean status, whereas different Lactobacillus species are associated both with a lean and an obese status. OBJECTIVES AND METHODS: We analyzed the fecal concentrations of Bacteroidetes, Firmicutes, Methanobrevibacter smithii, the genus Lactobacillus, five other Lactobacillus species previously linked with lean or obese populations, Escherichia coli and Bifidobacterium animalis in 263 individuals, including 134 obese, 38 overweight, 76 lean and 15 anorexic subjects to test for the correlation between bacterial concentration and body mass index (BMI). Of these subjects, 137 were used in our previous study. FINDINGS: Firmicutes were found in >98.5%, Bacteroidetes in 67%, M. smithii in 64%, E. coli in 51%, Lactobacillus species between 17 and 25% and B. animalis in 11% of individuals. The fecal concentration of Lactobacillus reuteri was positively correlated with BMI (coefficient=0.85; 95% confidence interval (CI) 0.12-0.58; P=0.02) in agreement with what was reported for Lactobacillus sakei. As reported, B. animalis (coefficient=-0.84; 95% CI -1.61 to -0.07; P=0.03) and M. smithii (coefficient=-0.43, 95% CI -0.90 to 0.05; P=0.08) were negatively associated with the BMI. Unexpectedly, E. coli was found here for the first time to negatively correlate with the BMI (coefficient=-1.05; 95% CI -1.60 to -0.50; P<0.001). CONCLUSION: Our findings confirm the specificity of the obese microbiota and emphasize the correlation between the concentration of certain Lactobacillus species and obesity.

Microbial culturomics: paradigm shift in the human gut microbiome study.

Comprehensive determination of the microbial composition of the gut microbiota and the relationships with health and disease are major challenges in the 21st century. Metagenomic analysis of the human gut microbiota detects mostly uncultured bacteria. We studied stools from two lean Africans and one obese European, using 212 different culture conditions (microbial culturomics), and tested the colonies by using mass spectrometry and 16S rRNA amplification and sequencing. In parallel, we analysed the same three samples by pyrosequencing 16S rRNA amplicons targeting the V6 region. The 32 500 colonies obtained by culturomics have yielded 340 species of bacteria from seven phyla and 117 genera, including two species from rare phyla (Deinococcus-Thermus and Synergistetes, five fungi, and a giant virus (Senegalvirus). The microbiome identified by culturomics included 174 species never described previously in the human gut, including 31 new species and genera for which the genomes were sequenced, generating c. 10 000 new unknown genes (ORFans), which will help in future molecular studies. Among these, the new species Microvirga massiliensis has the largest bacterial genome so far obtained from a human, and Senegalvirus is the largest virus reported in the human gut. Concurrent metagenomic analysis of the same samples produced 698 phylotypes, including 282 known species, 51 of which overlapped with the microbiome identified by culturomics. Thus, culturomics complements metagenomics by overcoming the depth bias inherent in metagenomic approaches.

Obesity-associated gut microbiota is enriched in Lactobacillus reuteri and depleted in Bifidobacterium animalis and Methanobrevibacter smithii.

BACKGROUND: Obesity is associated with increased health risk and has been associated with alterations in bacterial gut microbiota, with mainly a reduction in Bacteroidetes, but few data exist at the genus and species level. It has been reported that the Lactobacillus and Bifidobacterium genus representatives may have a critical role in weight regulation as an anti-obesity effect in experimental models and humans, or as a growth-promoter effect in agriculture depending on the strains. OBJECTIVES AND METHODS: To confirm reported gut alterations and test whether Lactobacillus or Bifidobacterium species found in the human gut are associated with obesity or lean status, we analyzed the stools of 68 obese and 47 controls targeting Firmicutes, Bacteroidetes, Methanobrevibacter smithii, Lactococcus lactis, Bifidobacterium animalis and seven species of Lactobacillus by quantitative PCR (qPCR) and culture on a Lactobacillus-selective medium. FINDINGS: In qPCR, B. animalis (odds ratio (OR)=0.63; 95% confidence interval (CI) 0.39-1.01; P=0.056) and M. smithii (OR=0.76; 95% CI 0.59-0.97; P=0.03) were associated with normal weight whereas Lactobacillus reuteri (OR=1.79; 95% CI 1.03-3.10; P=0.04) was associated with obesity. CONCLUSION: The gut microbiota associated with human obesity is depleted in M. smithii. Some Bifidobacterium or Lactobacillus species were associated with normal weight (B. animalis) while others (L. reuteri) were associated with obesity. Therefore, gut microbiota composition at the species level is related to body weight and obesity, which might be of relevance for further studies and the management of obesity. These results must be considered cautiously because it is the first study to date that links specific species of Lactobacillus with obesity in humans.

Specific adipocytokines profiles in patients with hyperactive and/or binge/purge form of anorexia nervosa.

OBJECTIVE: The aim of our study was to determine whether eating behaviors and/or physical activity level may explain contradicting results in adipocytokines levels in anorexia nervosa (AN). SUBJECTS/METHODS: Fasting levels of circulating adipocytokines (adiponectin, resistin and leptin), insulin, glucose, C-reactive protein, cytokines (tumor necrosis factor-alpha and interleukin (IL)-1beta), body composition and resting energy expenditure were measured in 24 women AN patients and 14 women controls. These parameters were compared according to AN subtypes: 15 patients with restrictive (R-AN) form versus 9 patients with binge/purge (BP-AN) form; 15 patients with hyperactive (H-AN) form versus 9 patients with nonhyperactive (NH-AN) form. RESULTS: BP-AN patients had significantly higher serum adiponectin levels compared with R-AN patients (P<0.05), and H-AN patients had higher serum leptin and lower serum resistin levels compared with NH-AN patients (P<0.05 for both). CONCLUSIONS: Our study shows specific adipocytokines profiles depending on the subtype of AN: restrictive versus binge/purge and hyperactive versus Nonhyperactive forms. We suggest that these biological signatures could interfere with the outcome of the disease.

Parallel increase of plasma apoproteins C-II and C-III in Type 2 diabetic patients.

AIMS: To determine plasma levels of apoprotein (apo) C-II and apoprotein C-III in Type 2 diabetic patients and to examine the clinical and biological factors that are associated with elevated apoC concentrations. METHODS: We measured apoC-II and apoC-III in total plasma and in non-high-density lipoprotein fractions by an immunoturbidimetric assay in 88 Caucasian Type 2 diabetic patients and in 138 healthy control subjects. RESULTS: Plasma levels of both apoC-II and apoC-III were increased in Type 2 diabetic patients. The clinical conditions associated with an increase of plasma apoC-II and apoC-III were abdominal obesity, body mass index, poor glycaemic control and lack of insulin treatment. However, when multivariate analysis was used, plasma apoCs levels correlated with triglyceride levels only. The apoC-III/apoC-II ratio was similar in the Type 2 diabetic and control subjects. CONCLUSIONS: Our study shows the parallel increase of apoC-II and C-III in Type 2 diabetic patients. This parallel increase is related to hypertriglyceridaemia only.

A novel mutation (E333D) in the thyroid hormone beta receptor causing resistance to thyroid hormone syndrome.

Resistance to thyroid hormone (RTH) is an inherited syndrome characterized by elevated serum thyroid hormones (TH), failure to suppress pituitary thyroid stimulating hormone (TSH) secretion, and variable peripheral tissue responsiveness to TH. The disorder is associated with diverse mutations in the thyroid hormone beta receptor (TRbeta). Here, we report a novel natural RTH mutation (E333D) located in the large carboxy-terminal ligand binding domain of TRbeta. The mutation was identified in a 22-year-old French woman coming to medical attention because of an increasing overweight. Biochemical tests showed elevated free thyroxine (T4: 20.8 pg/ml (normal, 8.5-18)) and triiodothyronine (T3: 5.7 pg/ml (normal, 1.4-4)) in the serum, together with an inappropriately nonsuppressed TSH level of 4.7 mU/ml (normal, 0.4-4). Her father and her brother's serum tests also showed biochemical abnormalities consistent with RTH. Direct sequencing of the TRbeta gene revealed a heterozygous transition 1284A>C in exon 9 resulting in substitution of glutamic acid 333 by aspartic acid residue (E333D). Further functional analyses of the novel TRbeta mutant were conducted. We found that the E333D mutation neither significantly affected the affinity of the receptor for T3 nor modified heterodimer formation with retinoid X receptor (RXR) when bound to DNA. However, in transient transfection assays, the E333D TRbeta mutant exhibited impaired transcriptional regulation on two distinct positively regulated thyroid response elements (F2- and DR4-TREs) as well as on the negatively regulated human TSHalpha promoter. Moreover, a dominant inhibition of the wild-type TRbeta counterpart transactivation function was observed on both a positive (F2-TRE) and a negative (TSHalpha) promoter. These results strongly suggest that the E333D TRbeta mutation is responsible for the RTH phenotype in the proposita's family.

Low-level arsenite activates the transcription of genes involved in adipose differentiation.

In this study we analyzed gene expression in 3T3-F442A pre-adipocyte cells that differentiate in the presence of micro-molar arsenate concentration. Two concentrations of arsenite (As2O3, 0.25 micromol/L and 0.5 micromol/L) were applied for three days with and without insulin (170 nmol/L) and gene expressions were evaluated by quantitative RT-PCR. The genes included genes of oxidative-stress responses: heme-oxygenase-1 (HO1) and the hypoxia inducible factor 1a (HIF1alpha), genes of cell-cycle: c-jun and Kruppel like factor 5 (KLF5), and genes that play important roles in adipose determination: a peroxisome proliferator-activated receptor (PPARgamma) and a CCAAT/ enhancer binding protein (C/EBPalpha). Arsenite induced the expression of HO1, HIF1alpha, KLF5, PPARgamma and C/EBPalpha. These results suggest that under condition of oxidative stress arsenite induces genes that are required for adipose differentiation.