Project description:Recent evidence suggests an important role of the gut microbiome in early life on immune cell entraining. Using two independent transgenic (Tg) lines of Alzheimer’s disease, we have demonstrated that life-long antibiotic (ABX)-perturbation of the gut microbiome is associated with reduced amyloid beta (Ab) plaque pathology and microglial phenotypes in male mice. Furthermore, fecal microbiota transfer (FMT) from age-matched APPPS1-21 Tg mice into long-term ABX-treated male APPPS1-21 mice partially restored amyloidosis and microgliosis, thus establishing causality. in the current studies, we planned to investigate the transcriptome profiles in APPPS1-21 mice treated with short-term abx (PND14-21) compared with vehicle treated groups in genotype-, sex- and time -dependent manner. Most importantly, we also investigated if fecal microbiota transplants from age-matched Tg male mice into short-term abx (PND14-21)-treated male mice restores brain transcriptomes to that of obsreved in vehicle-treated male mice at 9 weeks of age.
Project description:Microbial colonization of the human gastrointestinal tract plays an important role in establishing health and homeostasis. However, the time-dependent and related functional signatures of microbial and human proteins during early colonization of the gut have yet to be determined. Thus, we employed shotgun proteomics via nano-2D-LC-MS/MS to simultaneously monitor microbial and human proteins in fecal samples from a healthy preterm infant during early development. ). All MS/MS spectra were searched against a predicted protein database containing 25 microbial species along with the Human RefSeq2011 genome using the SEQUEST algorithm (Eng et al, 1994), and filtered with DTASelect version 1.9 (Tabb et al, 2002) at the peptide level with standard filters [SEQUEST Xcorrs of at least 1.8 (+1), 2.5 (+2) 3.5 (+3)] organizing identified peptides to their corresponding protein sequences. This study provides the first elucidation of coordinated human and microbial proteins in the infant gut during early development.
Project description:A metaproteomics analysis was conducted on the infant fecal microbiome to characterize global protein expression in 8 samples obtained from infants with a range of early-life experiences. Samples included breast-, formula- or mixed-fed, mode of delivery, and antibiotic treatment and one set of monozygotic twins. Although label-free mass spectrometry-based proteomics is routinely used for the identification and quantification of thousands of proteins in complex samples, the metaproteomic analysis of the gut microbiome presents particular technical challenges. Among them: the extreme complexity and dynamic range of member taxa/species, the need for matched, well-annotated metagenomics databases, and the high inter-protein sequence redundancy/similarity between related members. In this study, a metaproteomic approach was developed for assessment of the biological phenotype and functioning, as a complement to 16S rRNA sequencing analysis to identify constituent taxa. A sample preparation method was developed for recovery and lysis of bacterial cells, followed by trypsin digestion, and pre-fractionation using Strong Cation Exchange chromatography. Samples were then subjected to high performance LC-MS/MS. Data was searched against the Human Microbiome Project database, and a homology-based meta-clustering strategy was used to combine peptides from multiple species into representative proteins. Bacterial taxonomies were also identified, based on species-specific protein sequences, and protein metaclusters were assigned to pathways and functional groups. The results obtained demonstrate the applicability of this approach for performing qualitative comparisons of human fecal microbiome composition, physiology and metabolism, and also provided a more detailed assessment of microbial composition in comparison to 16S rRNA.
Project description:Background - Prepregnancy overweight and obesity promote deleterious health impacts on both mothers during pregnancy and the offspring. Significant changes in the maternal peripheral blood mononuclear cells (PBMCs) gene expression due to obesity are well-known. However, during pregnancy the impact of overweight on immune cell gene expression and its association with maternal and infant outcomes is not well explored. Methods – Blood samples were collected from healthy normal weight (NW, BMI 18.5-24.9) or overweight (OW, BMI 25-29.9) 2nd parity pregnant women at 12, 24 and 36 weeks of pregnancy. PBMCs were isolated from the blood and subjected to mRNA sequencing. Maternal and infant microbiota were analyzed by 16S rRNA gene sequencing. Integrative multi-omics data analysis was performed to evaluate the association of gene expression with maternal diet, gut microbiota, milk composition, and infant gut microbiota. Results - Gene expression analysis revealed that 453 genes were differentially expressed in the OW women compared to NW women at 12 weeks of pregnancy, out of which 354 were upregulated and 99 were downregulated. Several up-regulated genes in the OW group were enriched in inflammatory, chemokine-mediated signaling and regulation of interleukin-8 production-related pathways. At 36 weeks of pregnancy healthy eating index score was positively associated with several genes that include, DTD1, ELOC, GALNT8, ITGA6-AS1, KRT17P2, NPW, POT1-AS1 and RPL26. In addition, at 36 weeks of pregnancy, genes involved in adipocyte functions, such as NG2 and SMTNL1, were negatively correlated to human milk 2’FL and total fucosylated oligosaccharides content collected at 1 month postnatally. Furthermore, infant Akkermansia was positively associated with maternal PBMC anti-inflammatory genes that include CPS1 and RAB7B, at 12 and 36 weeks of pregnancy. Conclusions – These findings suggest that prepregnancy overweight impacts the immune cell gene expression profile, particularly at 12 weeks of pregnancy. Further, deciphering the complex association of PBMC’s gene expression levels with maternal gut microbiome and milk composition and infant gut microbiome may aid in developing strategies to mitigate obesity-mediated effects.
Project description:In a cohort consisting of 32 mother-infant dyads, we profiled the fecal metabolome at birth and at 3 and 6 months of infant age. Metagenomes from the same samples were also generated.