Project description:Maternal secretor status is one of the determinants of human milk oligosaccharides (HMOs) composition, which in turn changes the gut microbiota composition of infants. To understand if this change in gut microbiota impacts immune cell composition, intestinal morphology and gene expression, day 21-old germ-free mice were transplanted with fecal microbiota from infants whose mothers were either secretors (SMM) or non-secretors (NSM) or from infants consuming dairy-based formula (MFM). For each group, one set of mice was supplemented with HMOs. HMO supplementation did not significantly impact the microbiota diversity however, SMM mice had higher abundance of genus Bacteroides, Bifidobacterium, and Blautia, whereas, in the NSM group, there were higher abundance of Akkermansia, Enterocloster, and Klebsiella. In MFM, gut microbiota was represented mainly by Parabacteroides, Ruminococcaceae_unclassified, and Clostrodium_sensu_stricto. In mesenteric lymph node, Foxp3+ T cells and innate lymphoid cells type 2 (ILC2) were increased in MFM mice supplemented with HMOs while in the spleen, they were increased in SMM+HMOs mice. Similarly, serum immunoglobulin A (IgA) was also elevated in MFM+HMOs group. Distinct global gene expression of the gut was observed in each microbiota group, which was enhanced with HMOs supplementation. Overall, our data shows that distinct infant gut microbiota due to maternal secretor status or consumption of dairy-based formula and HMO supplementation impacts immune cell composition, antibody response and intestinal gene expression in a mouse model.
Project description:Folic acid deficiency is common worldwide and is linked to intestinal flora imbalance. The intestinal microbial utilization of folic acid based on model animals faces the challenges of repeatability and individual variability. In this study, we built an in vitro fecal slurry culture model deficient in folic acid. We examined the effects of supplementation with different forms of folic acid (5-methyltetrahydrofolate and non-reduced folic acid) on the modulation of intestinal flora. 16S rDNA gene sequencing showed alpha diversity increased after folic acid supplementation compared to fermentation samples with folic acid deficiency. In the non-reduced folic acid (FA) group, the relative abundance of the Firmicutes phylum dropped to 56.7%, whereas in the 5-methyltetrahydrofolate (MTHF) supplementation group, it grew to 64.9%. Lactobacillus genera became more prevalent, reaching 22.8% and 30.8%, respectively. Additionally, Bifidobacterium and Pedioccus, two common probiotic bacteria, were in higher abundance. Short-chain fatty acids (SCFAs) analysis showed that supplementation with folic acid (non-reduced folic acid, 5-methyltetrahydrofolate) decreased acetic acid and increased the fermentation yield of isobutyric acid. The in vitro fecal slurry culture model developed in this study can be utilized as a human folic acid deficiency model for studying intestinal microbiota and demonstrated that both 5-methyltetrahydrofolate and non-reduced folic acid have effects on the regulation of intestinal microecology.
Project description:The prevalence of immune-mediated diseases such as allergies and autoimmune diseases is on the rise in the developed world. Microbial exposure is known to modulate the risk for these diseases. In order to explore differences in the gene expression patterns induced in utero in infants born in contrasting standards of living and hygiene, we collected umbilical cord blood RNA samples from full-term newborn infants born with normal vaginal delivery in Finland (modern society), Estonia (rapidly developing society) and the Republic of Karelia, Russia (poor economical conditions). Transcriptomic profiles were analyzed using whole genome microarrays including gender, gestational age, birth month and HLA allele genotype as confounding variables in the analysis. The data revealed that the whole blood transcriptome of Finnish and Estonian neonates differ from their Karelian counterparts. Samples from Karelian infants had an increase in transcripts associated with LPS induction and bacterial sepsis observed in 1-year-old infants in earlier studies. The results suggest exposure to toll like receptor (TLR) ligands and a more matured immune response in infants born in Petrozavodsk compared to the Finnish and Estonian infants. These results further support the concept of a conspicuous plasticity in the developing immune system: the environmental factors that play a role in the susceptibility/protection towards immune-mediated diseases begin to shape the neonatal immunity already in utero and direct the maturation of both the adaptive and the innate immune responses in accordance with the surrounding microbial milieu. Umbilical cord blood was drawn into Tempus Blood RNA tubes (Applied Biosystems) from children born between January and May 2010 at the maternity unit of Jorvi hospital (Espoo, Finland; n=48), maternity units of Tartu and PM-CM-5lva (Estonia; n=25), or two maternity departments in Petrozavodsk (capital of the Republic of Karelia, Russian Federation; n=40) according to the manufacturerM-BM-4s protocol and then stored in M-bM-^HM-^R70 M-BM-0C until analyzed. All newborn infants were full-term (>36 gestational weeks) and born vaginally. 113 cord blood RNA samples were analyzed with Affymetrix U219 gene array. Gender, pregnancy week, month of birth and HLA risk class were included as confounding factors in the analysis model.
Project description:The rate of cesarean delivery (CD) in China has risen sharply and the high rate was reported to be associated with increased risk of disease in the offspring. However, there is little research on the molecular mechanism of critical pathways and gene signatures involved in the neonatal immunity of cesarean-born infants. This study was undertaken to identify unique gene signatures which was involved in the neonatal immunity of cesarean-born infants through large-scale RNA-sequencing. Genes differentially expressed in cesarean-born infants were identified and further validated through quantitative real-time PCR (RT-qPCR). Moreover, we employed weighted gene co-expression network analysis (WGCNA) to identify highly connected genes that were correlated with neonatal inflammation. In total, 73 differentially expressed genes (DEGs) were identified between cesarean-born infants and normal vagina childbirth. The results obtained by secondary validation indicated that GATM, MIF, IFI27, IL1B, CA1, and EPHB1 were significantly upregulated in phenotype CD, while CYP2A6 and DLK1 were significantly down regulated. Further, functional and pathway enrichment analysis reveals perturbation of several DEGs involved in signaling pathways pertaining to immunoregulation, inflammation, apoptosis, and nervous development. Additionally, HLA-DOB popped out as a core gene in the process of inflammation, which might indicate the risk of cesarean-born infants for inflammatory disease. Notably, our study for the first time has documented gene signatures PIK3CA, PTPRC, SOS1, IL6ST, and MALT1, which were found to be involved in neonatal inflammation. Taken together, the full expression repertoire including the differentially expressed gene sets and core differentially co-expressed genes should provide an excellent resource for identifying potential biomarkers of cesarean-born infants with inflammation, and formulating new hypotheses for physiological functions and the discovery of novel therapeutic targets for inflammatory disease.
Project description:The prevalence of immune-mediated diseases such as allergies and autoimmune diseases is on the rise in the developed world. Microbial exposure is known to modulate the risk for these diseases. In order to explore differences in the gene expression patterns induced in utero in infants born in contrasting standards of living and hygiene, we collected umbilical cord blood RNA samples from full-term newborn infants born with normal vaginal delivery in Finland (modern society), Estonia (rapidly developing society) and the Republic of Karelia, Russia (poor economical conditions). Transcriptomic profiles were analyzed using whole genome microarrays including gender, gestational age, birth month and HLA allele genotype as confounding variables in the analysis. The data revealed that the whole blood transcriptome of Finnish and Estonian neonates differ from their Karelian counterparts. Samples from Karelian infants had an increase in transcripts associated with LPS induction and bacterial sepsis observed in 1-year-old infants in earlier studies. The results suggest exposure to toll like receptor (TLR) ligands and a more matured immune response in infants born in Petrozavodsk compared to the Finnish and Estonian infants. These results further support the concept of a conspicuous plasticity in the developing immune system: the environmental factors that play a role in the susceptibility/protection towards immune-mediated diseases begin to shape the neonatal immunity already in utero and direct the maturation of both the adaptive and the innate immune responses in accordance with the surrounding microbial milieu. These 15 rehybridized samples were only utilized in the batch correction and excluded from any further analysis steps. Umbilical cord blood was drawn into Tempus Blood RNA tubes (Applied Biosystems) from children born at the maternity unit of Jorvi hospital (Espoo, Finland; n=4), maternity units of Tartu and PM-CM-5lva (Estonia; n=4), or two maternity departments in Petrozavodsk (capital of the Republic of Karelia, Russian Federation; n=7) according to the manufacturerM-BM-4s protocol and then stored in -70 M-BM-0C until analyzed.