Endogenous Ethanol and Triglyceride Production by Gut Pichia kudriavzevii, Candida albicans and Candida glabrata Yeasts in Non-Alcoholic Steatohepatitis.

Nonalcoholic steatohepatitis (NASH) increases with fructose consumption and metabolic syndrome and has been recently linked with endogenous ethanol production, notably by high alcohol-producing Klebsiella pneumoniae (HiAlc Kpn). Candida yeasts are the main causes of auto-brewery syndromes but have been neglected in NASH. Here, the fecal ethanol and microbial content of 10 cases and 10 controls were compared. Ethanol was measured by gas chromatography-mass spectrometry. Species identification was performed by MALDI-TOF MS, and triglyceride production was assessed by a colorimetric enzymatic assay. The fecal ethanol concentration was four times higher in patients with NASH (median [interquartile range]: 0.13 [0.05-1.43] vs. 0.034 [0.008-0.57], p = 0.037). Yeasts were isolated from almost all cases but not from controls (9/10 vs. 0/10, p = 0.0001). Pichia kudriavzevii was the most frequent (four patients), while Candida glabrata, Candida albicans, and Galactomyces geotrichum were identified in two cases each. The concentration of ethanol produced by yeasts was 10 times higher than that produced by bacteria (median, 3.36 [0.49-5.60] vs. 0.32 [0.009-0.43], p = 0.0029). Using a 10% D-fructose restricted medium, we showed that NASH-associated yeasts transformed fructose in ethanol. Unexpectedly, yeasts isolated from NASH patients produced a substantial amount of triglycerides. Pichia kudriavzevii strains produced the maximal ethanol and triglyceride levels in vitro. Our preliminary human descriptive and in vitro experimental results suggest that yeasts have been neglected. In addition to K. pneumoniae, gut Pichia and Candida yeasts could be linked with NASH pathophysiology in a species- and strain-specific manner through fructose-dependent endogenous alcohol and triglyceride production.

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.

Collinsella vaginalis sp. nov. strain Marseille-P2666T, a new member of the Collinsella genus isolated from the genital tract of a patient suffering from bacterial vaginosis.

A strictly anaerobic, Gram-stain-positive, non motile and non-spore-forming rod-shaped bacterium, strain Marseille-P2666T, was isolated using the culturomics approach from a vaginal sample of a French patient suffering from bacterial vaginosis. Cells were saccharolytic and were negative for catalase, oxidase, urease, nitrate reduction, indole production, hydrolysis of aesculin and gelatin. Strain Marseille-P2666T exhibited 97.04 % 16S rRNA sequence similarity to Collinsella tanakaei type strain YIT 12063T, the phylogenetically closest species with standing in nomenclature. The major fatty acids were C18:1ω9 (38 %), C16 : 0 (24 %) and C18 : 0 (19 %). The G+C content of the genome sequence of strain Marseille-P2666T is 64.6 mol%. On the basis of its phenotypic, phylogenetic and genomic features, strain Marseille-P2666T (=CSUR 2666T=DSM103342T) was classified as type strain of a novel species within the genus Collinsella for which the name Collinsella vaginalis sp. nov. is proposed.

Genome sequence and description of Gracilibacillus timonensis sp. nov. strain Marseille-P2481T , a moderate halophilic bacterium isolated from the human gut microflora.

Microbial culturomics represents an ongoing revolution in the characterization of the human gut microbiota. By using three culture media containing high salt concentrations (10, 15, and 20% [w/v] NaCl), we attempted an exhaustive exploration of the halophilic microbial diversity of the human gut and isolated strain Marseille-P2481 (= CSUR P2481 =  DSM 103076), a new moderately halophilic bacterium. This bacterium is a Gram-positive, strictly aerobic, spore-forming rod that is motile by use of a flagellum and exhibits catalase, but not oxidase activity. Strain Marseille-P2481 was cultivated in media containing up to 20% (w/v) NaCl, with optimal growth being obtained at 37°C, pH 7.0-8.0, and 7.5% [w/v] NaCl). The major fatty acids were 12-methyl-tetradecanoic acid and hexadecanoic acid. Its draft genome is 4,548,390 bp long, composed of 11 scaffolds, with a G+C content of 39.8%. It contains 4,335 predicted genes (4,266 protein coding including 89 pseudogenes and 69 RNA genes). Strain Marseille-P2481 showed 96.57% 16S rRNA sequence similarity with Gracilibacillus alcaliphilus strain SG103T , the phylogenetically closest species with standing in nomenclature. On the basis of its specific features, strain Marseille-P2481T was classified as type strain of a new species within the genus Gracilibacillus for which the name Gracilibacillus timonensis sp. nov. is formally proposed.

Microbial Culturomics Application for Global Health: Noncontiguous Finished Genome Sequence and Description of Pseudomonas massiliensis Strain CB-1T sp. nov. in Brazil.

Culturomics is a new postgenomics field that explores the microbial diversity of the human gut coupled with taxono-genomic strategy. Culturomics, and the microbiome science more generally, are anticipated to transform global health diagnostics and inform the ways in which gut microbial diversity contributes to human health and disease, and by extension, to personalized medicine. Using culturomics, we report in this study the description of strain CB1T ( = CSUR P1334 = DSM 29075), a new species isolated from a stool specimen from a 37-year-old Brazilian woman. This description includes phenotypic characteristics and complete genome sequence and annotation. Strain CB1T is a gram-negative aerobic and motile bacillus, exhibits neither catalase nor oxidase activities, and presents a 98.3% 16S rRNA sequence similarity with Pseudomonas putida. The 4,723,534 bp long genome contains 4239 protein-coding genes and 74 RNA genes, including 15 rRNA genes (5 16S rRNA, 4 23S rRNA, and 6 5S rRNA) and 59 tRNA genes. Strain CB1T was named Pseudomonas massiliensis sp. nov. and classified into the family Pseudomonadaceae. This study demonstrates the usefulness of microbial culturomics in exploration of human microbiota in diverse geographies and offers new promise for incorporating new omics technologies for innovation in diagnostic medicine and global health.

Gut microbiome-based medical methodologies for early-stage disease prevention.

Recent advancements highlight the important role of gut microbiome in human health. However, a variety of endogenous and exogenous factors, such as genes, foods, drugs, environmental pollutions, oxidative stress, etc., may interfere with the gut microbiome in vivo and increase risks of digestive system diseases, cardiovascular diseases, neurological diseases, obesity, diabetes, cancers, and so on. Abundant discoveries listed in this work support that changes in the composition of the gut microbiome may be potentially used as sensitive early-stage diagnostic biomarkers and that the gut microbiome could be a promising therapeutic target for systemic prevention of multiple human diseases. Interestingly, the microbial culturomics revolution makes it possible to identify much more species and several new species in the gut microbiome. Several innovative articles published by Science and Nature in 2016 further put forward the feasibility of these perspectives, lay grounds for establishing standardized human gut microbiome compositions, and are particularly important for monitoring dysbiosis of the gut microbiome and for precisely reshaping a dysfunctional gut microbiome. Hypothetically, keeping and reconstructing an optimized gut microbiome would be essential to prevent the occurrence of various human diseases. Hence, these advancements have impressive clinical implications for predicting abnormal healthy status of human beings and for preventing the initiation of systemic disorders at an early stage.