Landscape of the gut mycobiome dynamics during pregnancy and its relationship with host metabolism and pregnancy health.

OBJECTIVE: The remodelling of gut mycobiome (ie, fungi) during pregnancy and its potential influence on host metabolism and pregnancy health remains largely unexplored. Here, we aim to examine the characteristics of gut fungi in pregnant women, and reveal the associations between gut mycobiome, host metabolome and pregnancy health. DESIGN: Based on a prospective birth cohort in central China (2017 to 2020): Tongji-Huaxi-Shuangliu Birth Cohort, we included 4800 participants who had available ITS2 sequencing data, dietary information and clinical records during their pregnancy. Additionally, we established a subcohort of 1059 participants, which included 514 women who gave birth to preterm, low birthweight or macrosomia infants, as well as 545 randomly selected controls. In this subcohort, a total of 750, 748 and 709 participants had ITS2 sequencing data, 16S sequencing data and serum metabolome data available, respectively, across all trimesters. RESULTS: The composition of gut fungi changes dramatically from early to late pregnancy, exhibiting a greater degree of variability and individuality compared with changes observed in gut bacteria. The multiomics data provide a landscape of the networks among gut mycobiome, biological functionality, serum metabolites and pregnancy health, pinpointing the link between Mucor and adverse pregnancy outcomes. The prepregnancy overweight status is a key factor influencing both gut mycobiome compositional alteration and the pattern of metabolic remodelling during pregnancy. CONCLUSION: This study provides a landscape of gut mycobiome dynamics during pregnancy and its relationship with host metabolism and pregnancy health, which lays the foundation of the future gut mycobiome investigation for healthy pregnancy.

Bartonella choladocola sp. nov. and Bartonella apihabitans sp. nov., two novel species isolated from honey bee gut.

Bartonella is one of the noncore bacterial genera in the honey bee (Apis mellifera) gut. So far, only one species, Bartonella apis, has been described from the honey bee gut. Previous analyses based on the genomic information of isolates and metagenome-assembled genomes suggested the existence of multiple Bartonella species in the bee guts. Here, 10 strains were isolated and characterized from the gut of A. mellifera from Jilin Province, China. New isolates shared ＞95% 16S rRNA gene sequence similarity with other species of the genus Bartonella. Phylogenetic analysis revealed that new isolates clustered with other type strains of Bartonella, and the bee gut Bartonella could be classified into three clades. The in silico DDH and average nucleotide identity values between strains of different clusters from the honey bee gut are 29.1-32.5% and 87.6-89.3%, all below the recommended 70.0% and 95% cutoff points. Cells are Gram-staining-negative rods and can grow on the surface of Brain Heart Infusion agar plates supplemented with defibrinated sheep blood in an aerobic environment with 5% CO2 at 35-37 °C. Strains from different species varied in both phenotypic and chemotaxonomic characterizations. Comparative genomic analysis indicated that B. choladocola had unique sets of genes encoding invasin, representing the potential for this species to both live as a gut symbiont and also as an erythrocytic pathogen. Thus, we propose two novel species Bartonella choladocola sp. nov. whose type strain is W8125T(=JCM 35030T = ACCC 62057T), and Bartonella apihabitans sp. nov. whose type strain is W8097T(=JCM 35029T = ACCC 62056T).

Inflammatory bowel disease-associated Escherichia coli strain LF82 in the damage of gut and cognition of honeybees.

Patients with inflammatory bowel disease (IBD) are often accompanied with some cognitive impairment, but the mechanism is unclear. By orally exposing honeybees (Apis mellifera) to IBD-associated Escherichia coli LF82 (LF82), and non-pathogenic Escherichia coli MG1655 (MG1655) as the normal strain, we investigated whether and how LF82 induces enteritis-like manifestations and cognitive behavioral modifications in honeybees using multiparametric analysis. LF82 significantly increased gut permeability, impaired learning and memory ability in olfactory proboscis extension response conditioning, and shortened the lifespan of honeybees. Compared to MG1655, LF82 reduced the levels of tryptophan metabolism pathway substances in the honeybee gut. LF82 also upregulated genes involved in immune and apoptosis-related pathways and downregulated genes involved in G protein-coupled receptors in the honeybee brain. In conclusion, LF82 can induce enteritis-like manifestations and cognition impairment through gut metabolites and brain transcriptome alteration in honeybees. Honeybees can serve as a novel potential model to study the microbiota-gut-brain interaction in IBD condition.

Characterization of Bifidobacterium apousia sp. nov., Bifidobacterium choladohabitans sp. nov., and Bifidobacterium polysaccharolyticum sp. nov., three novel species of the genus Bifidobacterium from honey bee gut.

Bifidobacterium is one of the dominating bacterial genera in the honey bee gut, and they are the key degrader of diet polysaccharides for the host. Previous genomic analysis shows that they belong to separate phylogenetic clusters and exhibited different functional potentials in hemicellulose digestion. Here, three novel strains from the genus Bifidobacterium were isolated from the guts of the honey bee (Apis mellifera). Phylogenomic analysis showed that the isolates could be grouped into four phylogenetic clusters. The average nucleotide identity values between strains from different clusters are <95%, while strains in Cluster IV belong to the characterized species Bifidobacterium asteroides. Carbohydrate-active enzyme annotation confirmed that the metabolic capacity for carbohydrates varied between clusters of strains. Cells are Gram-positive rods; they grew both anaerobically and in a CO2-enriched atmosphere. All strains grew at a temperature range of 20-42 °C, with optimum growth at 35 °C. The pH range for growth was 5-9. Strains from different phylogenetic clusters varied in multiple phenotypic and chemotaxonomic characterizations. Thus, we propose three novel species Bifidobacterium apousia sp. nov. whose type strain is W8102T (=CGMCC 1.18893 T = JCM 34587 T), Bifidobacterium choladohabitans sp. nov., whose type strain is B14384H11T (=CGMCC 1.18892 T = JCM 34586 T), and Bifidobacterium polysaccharolyticum sp. nov. whose type strain is W8117T (=CGMCC 1.18894 T = JCM 34588 T).