ABSTRACT
BACKGROUND/OBJECTIVES: High salt intake has been linked to several diseases including obesity and an increased risk of death; however, fecal salinity and the ability of salt to alter the gut microbiota, which was recently identified as an instrumental factor for health and disease, remains poorly explored. METHODS/SUBJECTS: We analyzed the fecal samples of 1326 human individuals for salinity by refractometry, 572 for gut microbiota by culturomics, and 164 by 16S rRNA-targeted metagenomics. Geographical origin, age, gender, and obesity were tested as predictors of fecal salinity and halophilic diversity. All halophilic isolates were characterized by taxonogenomics and their genome sequenced. RESULTS: Fecal salinity was associated with obesity independently of geographical origin, gender, and age. The first 2 human-associated halophilic archaeal members were isolated along with 64 distinct halophilic species, including 21 new species and 41 known in the environment but not in humans. No halophiles grow in less than 1.5% salinity. Above this threshold, the richness of the halophilic microbiota was correlated with fecal salinity (r = 0.58, p < 0.0001). 16S metagenomics linked high fecal salinity to decreased diversity (linear regression, p < .035) and a depletion in anti-obesity Akkermansia muciniphila and Bifidobacterium, specifically B. longum and B. adolescentis. Genomics analysis suggested that halophilic microbes are not only transient passengers but may be residents of the human gut. CONCLUSIONS: High salt levels are associated with alteration of the gut microbial ecosystem and halophilic microbiota, as discovered during this study. Further studies should clarify if the gut microbiota alterations associated with high salt levels and the human halophilic microbiota could be causally related to human disease, such as obesity.
Subject(s)
Feces/microbiology , Gastrointestinal Microbiome/genetics , Inflammation/microbiology , Obesity/microbiology , Sodium Chloride, Dietary/adverse effects , Adult , Case-Control Studies , Female , Global Health , Humans , Inflammation/etiology , Inflammation/physiopathology , Male , Obesity/etiology , Obesity/physiopathology , RNA, Ribosomal, 16S/genetics , RefractometryABSTRACT
Bacillus salis strain ES3T (= CSUR P1478 = DSM 100598) is the type strain of B. salis sp. nov. It is an aerobic, Gram-positive, moderately halophilic, motile and spore-forming bacterium. It was isolated from commercial table salt as part of a broad culturomics study aiming to maximize the culture conditions for the in-depth exploration of halophilic bacteria in salty food. Here we describe the phenotypic characteristics of this isolate, its complete genome sequence and annotation, together with a comparison with closely related bacteria. Phylogenetic analysis based on 16S rRNA gene sequences indicated 97.5% similarity with Bacillus aquimaris, the closest species. The 8 329 771 bp long genome (one chromosome, no plasmids) exhibits a G+C content of 39.19%. It is composed of 18 scaffolds with 29 contigs. Of the 8303 predicted genes, 8109 were protein-coding genes and 194 were RNAs. A total of 5778 genes (71.25%) were assigned a putative function.
ABSTRACT
We report the isolation of three bacterial strains that could not be identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry screening. 'Gracilibacillus phocaeensis' sp. nov., 'Sediminibacillus massiliensis' sp. nov. and 'Virgibacillus ndiopensis' sp. nov. are halophilic species isolated from salty human stools by culturomics.
ABSTRACT
We report the main characteristics of 'Bacillus dakarensis' P3515T sp. nov., 'Bacillus sinesaloumensis' P3516T sp. nov., 'Gracilibacillus timonensis' P2481T sp. nov., 'Halobacillus massiliensis' P3554T sp. nov., 'Lentibacillus massiliensis' P3089T sp. nov., 'Oceanobacillus senegalensis' P3587T sp. nov., 'Oceanobacillus timonensis' P3532T sp. nov., 'Virgibacillus dakarensis' P3469T sp. nov. and 'Virgibacillus marseillensis' P3610T sp. nov., that were isolated in 2016 from salty stool samples (≥1.7% NaCl) from healthy Senegalese living at Dielmo and N'diop, two villages in Senegal.
ABSTRACT
We report here the main characteristics of 'Halomonas massiliensis' strain Marseille-P2426(T) (CSUR P2426), a new species of the Halomonas genus that was isolated from the stool sample of a healthy 24-year-old Senegalese man.
ABSTRACT
We propose the main phenotypic characteristics and the complete genome sequence and annotation of Planococcus massiliensis strain ES2(T) (= CSUR P1103 = DSM 28915), the type strain of P. massiliensis sp. nov., isolated from a faeces sample collected from a healthy Senegalese man. It is an aerobic, Gram-positive, moderately halophilic, motile and rod-shaped bacterium. The 3 357 017 bp long genome exhibits a G+C content of 46.0% and contains 3357 protein-coding genes and 48 RNA genes.