Project description:Complex oligosaccharides found in human milk play a vital role in gut microbiome development for the human infant. Bovine milk oligosaccharides (BMO) have similar structures with those derived from human milk, but have not been well studied for their effects on the healthy adult human gut microbiome. Healthy human subjects consumed BMO over two-week periods at two different doses and provided fecal samples. Metatranscriptomics of fecal samples was conducted to determine microbial and host gene expression in response to the supplement. Fecal samples were also analyzed by mass spectrometry to determine levels of undigested BMO. No changes were observed in microbiome activity across all participants. Repeated sampling enabled subject-specific analyses: four of six participants had minor, yet statistically significant, changes in microbial activity. No significant change was observed in the gene expression of host cells in stool. Levels of BMO excreted in feces after supplementation were not significantly different from placebo and were not correlated with dosage or expressed microbial enzyme levels. Collectively, these data suggest that BMO is fully digested in the human gastrointestinal tract prior to stool collection. Participants’ gut microbiomes remained stable but varied between individuals. Additionally, the unaltered host transcriptome provides further evidence for the safety of BMO as a dietary supplement or food ingredient.
Project description:We used 16S V3/V4 region amplification to evaluate the composition of bacteria species in mouse fecal pellets after vehicle or ABX treatment and before and after fecal matter transplant.
Project description:Mammalian feces can be collected non-invasively during field research and provides valuable information on the ecology and evolution of the host individuals. Undigested food objects, genome/metagenome, steroid hormones, and stable isotopes obtained from fecal samples provide evidence on diet, host/symbiont genetics, and physiological status of the individuals. However, proteins in mammalian feces have hardly been studied, which hampers the molecular investigations into the behavior and physiology of the host individuals. Here, we apply mass spectrometry-based proteomics to fecal samples (n = 10) that were collected from infant, juvenile, and adult captive Japanese macaques (Macaca fuscata) to describe the proteomes of the host, food, and intestinal microbes. The results show that fecal proteomics is a useful method to investigate dietary changes along with breastfeeding and weaning, to reveal the organ/tissue and taxonomy of dietary items, and to estimate physiological status inside intestinal tracts. These types of insights are difficult or impossible to obtain through other molecular approaches. Most mammalian species are facing extinction risk and there is an urgent need to obtain knowledge on their ecology and evolution for better conservation strategy. The fecal proteomics framework we present here is easily applicable to wild settings and other mammalian species, and provides direct evidence of their behavior and physiology.
Project description:The aim of this study was to test the hypothesis that replenishing the microbiota with a fecal microbiota transplant (FMT) can rescue a host from an advanced stage of sepsis. We developed a clinically-relevant mouse model of lethal polymicrobial gut-derived sepsis in mice using a 4-member pathogen community (Candida albicans, Klebsiella oxytoca, Serratia marcescens, Enterococcus faecalis) isolated from a critically ill patient. In order to mimic pre-operative surgical patient condition mice were exposed to food restriction and antibiotics. Approximately 18 hours prior to surgery food was removed from the cages and the mice were allowed only tap water. Each mouse received an intramuscular Cefoxitin injection 30 minutes prior to the incision at a concentration of 25 mg/kg into the left thigh. Mice were then subjected to a midline laparotomy, 30% hepatectomy of the left lateral lobe of the liver and a direct cecal inoculation of 200 µL of the four pathogen community. On postoperative day one, the mice were administered rectal enema. Mice were given either 1 ml of fecal microbiota transplant (FMT) or an autoclaved control (AC). This was again repeated on postoperative day two. Mice were then followed for mortality. Chow was restored to the cages on postoperative day two, approximately 45 hours after the operation. The injection of fecal microbiota transplant by enema significantly protected mice survival, reversed the composition of gut microflora and down-regulated the host inflammatory response. The cecum, left lobe of the liver, and spleen were isolated from mice for microarray processing with three or more replicates for six expermental conditions: non-treated control, SAHC POD1, SAHC.AC POD2, SAHC.FMT POD2, SAHC.AC POD7, SAHC.FMT POD7
Project description:We compared dsDNA- and cssDNA-mediated whole transcriptome response in cultured primary T cells. T cells were electroporated with the same amount (1 µg) of dsDNA or cssDNA, GFP mRNA or vehicle (H2O). 24 hours post treatment, cell pellets were collected for transcriptome analysis by RNA sequencing.
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:We used 16S V3/V4 region amplification to evaluate the composition of bacteria species in mouse fecal pellets. Fecel pellets were collected from young-adult (12 weeks old) wild type C57Bl/6 mice and aged (72 weeks old) wild type C57Bl/6 mice after 21 days of vehicle or antibiotics treatment (to induce gut microbiota depletion). In one sequencing round, we sequenced a total of 12 different fecal samples (3 young control, 3 aged control, 3 young depleted gut microbiota (ABX) and 3 aged depleted gut microbiota (ABX)). Amplicons were indexed using the Nextera XT Index Kit and pooled into a library for Illumina sequencing.