Olsenella timonensis sp. nov., a new bacteria species isolated from the human gut microbiota

Gut Microbiota Composition in the First and Third Trimester of Pregnancy among Malay Women is Associated with Body Mass Index: A Pilot Study

Background

This study has analysed the pattern of gut microbiota during the first and third trimesters among pregnant Malay women.

Methods

This was a pilot prospective observational study involving 12 pregnant Malay women without any endocrine disorders and on neither antibiotics nor probiotics. Demographic details and anthropometric measurements were obtained, and the faecal 16S ribosomal ribonucleic acid (rRNA) metagenome microbiota of the first and third trimesters (T1 and T3) were analysed. Univariate and multivariate statistics, partial least squares discriminant analysis (PLSDA) and Kendall rank correlation testing were used to identify key genera and associations with pregnancy trimester and body mass index (BMI).

Results

The most abundant phyla were Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria, with significant differences in composition at the genus level demonstrated between T1 and T3. Sequencing showed a statistically significant difference in beta diversity between normal and abnormal BMI at all taxonomic ranks (R ² = 0.60; Q ² = 0.23) and genus levels (R ² = 0.57; Q ² = 0.37). The relative abundances of Akkermansia (P < 0.05; false discovery rate [FDR] < 0.05), Olsenella (P < 0.05; FDR < 0.05) and Oscillospira (P < 0.05; FDR < 0.05) were found to be significantly higher in normal BMI cases by 2.4, 3.4 and 3.1 times, respectively.

Conclusion

Three genera (Akkermansia, Olsenella and Oscillospira) were correlated with normal BMI during pregnancy. All three could be promising biotherapeutic targets in body weight regulation during pregnancy, subsequently reducing complications associated with higher BMI.

New human-associated species of the family Atopobiaceae and proposal to reclassify members of the genus Olsenella

Five novel bacterial strains, Marseille-P1476^T (=CSURP1476^T=DSM 100642^T), Marseille-P3256^T (=CSURP3256^T=CECT 9977^T), Marseille-P2936^T (=CSURP2936^T=DSM 103159^T), Marseille-P2912^T (=CSURP2912^T=DSM 103345^T) and Marseille-P3197^T (=CSURP3197^T=CCUG 71847^T), were isolated from various human specimens. These five strains were not identified at the species level by matrix-assisted laser desorption/ionization time of flight mass spectrometry. Following 16S rRNA gene sequence comparisons with the GenBank database, the highest nucleotide sequence similarities of all studied strains were obtained to members of the paraphyletic genus Olsenella. A polyphasic taxono-genomic strategy (16S rRNA gene-based and core genome-based phylogeny, genomic comparison, phenotypic and biochemical characteristics) enabled us to better classify these strains and reclassify Olsenella species. Among the studied strains, Marseille-P1476^T, Marseille-P2936^T and Marseille-P3197^T belonged to new species of the genus Olsenella for which we propose the names Olsenella massiliensis sp. nov., Olsenella phocaeensis sp. nov. and Olsenella urininfantis sp. nov., respectively. Strains Marseille-P2912^T and Marseille-P3256^T belonged to a new genus for which the names Thermophilibacter provencensis gen. nov., sp. nov. and Thermophilibacter mediterraneus gen. nov., sp. nov. are proposed, respectively. We also propose the creation of the genera Parafannyhessea gen. nov., Tractidigestivibacter gen. nov. and Paratractidigestivibacter gen. nov. and the reclassification of Olsenella umbonata as Parafannyhessea umbonata comb. nov., Olsenella scatoligenes as Tractidigestivibacter scatoligenes comb. nov., and Olsenella faecalis as Paratractidigestivibacter faecalis comb. nov.