Project description:To investigate the intestinal ileum response to dietary tryptophan deficiency and the contribution of the intestinal microbiome in regulating these responses
Project description:Nutrition has a vital role in shaping the intestinal microbiome. The impact of nutrients and the consequences of enteral deprivation on the small intestinal mucosal microbiota, specifically in early life, has not been well described. Our aim was to study the impact of enteral deprivation on the small intestine mucosal microbiome and to search for factors that shape this interaction in early life. Host seem to be the most dominant factor in the structure of the early life mucosal microbial small intestine community. Under conditions of nutrient deprivation, there are specific changes in host proteomics. Further research is needed to better define and understand this host-microbe-nutrition interaction in the small intestine.
Project description:This clinical trial tests whether daily fiber supplementation will change the mucosal microbiome of the colon. The microbiome are microorganisms that live in the human gut. They serve a vital role in maintaining health. Certain microbial strains are associated with the growth of colon polyps, which eventually could go on to form colon cancer. Giving dietary fiber supplements may help prevent precancerous polyps from ever developing.
Project description:Mechanical bowel preparation for left-sided colorectal surgery remains standard in most cases. However, there are some discrepancies on how to prepare the bowl, while rectal enema and oral agents are both available methods.
The knowledge of intestinal microbiome role on surgical outcomes is increasing, since few recent reports linked microbiome composition to postoperative complications, such as anastomotic insufficiency. Although, it is not clear how the bowel preparation affects the gut microbiome. Therefore, different bowel preparation techniques impact on gut microbiome will be studied.
Project description:The small intestine is responsible for nutrient absorption and it is one of the most important interfaces between the environment and our body. During aging, changes in the structure of the epithelium lead to food malabsorption and reduced barrier function thus increasing disease risk in aging. The molecular drivers of these alterations remain poorly understood. Here, we compared the proteomes of small intestinal crypts from mice across different anatomical regions and age groups. We found that aging alters epithelial immune responses, metabolic networks and stem cell proliferation, and it is accompanied by a region-dependent skewing in the cellular composition of the intestinal epithelium. Of note, a short period of dietary restriction followed by re-feeding partially restores the epithelium to a youthful state by promoting the differentiation of intestinal stem cells (ISCs) towards the secretory lineage. Using in vitro and in vivo studies, we identify Hmgcs2 (3-hydroxy-3-methylglutaryl-CoA synthetase 2) – the rate limiting enzyme in the synthesis of ketone bodies – as a modulator of ISCs differentiation, which responds to dietary changes. This study provides an atlas of age-dependent proteome changes in defined regions of the intestinal epithelium and characterizes how young and old mice adapt to drastic changes of diet, such as dietary restriction and re-feeding.
Project description:Little is known about how interactions between diet, intestinal stem cells (ISCs) and immune cells impact the early steps of intestinal tumorigenesis. Here, we show that a high fat diet (HFD) reduces the expression of the major histocompatibility complex II (MHC-II) genes in intestinal epithelial cells including ISCs. This decline in epithelial MHC-II expression in a HFD correlates with reduced diversity of the intestinal microbiome and is recapitulated in antibiotic treated and germ-free mice on a control diet. Mechanistically, pattern recognition receptor (PRR) and IFN g signaling regulate epithelial MHC-II expression where genetic ablation of these signaling pathways dampen MHC-II epithelial expression. Interestingly, upon loss of the tumor suppressor gene Apc in a HFD, MHC-II- ISCs harbor greater in vivo tumor-initiating capacity than their MHC-II+ counterparts when transplanted into immune-component hosts but not immune-deficient hosts, thus implicating a role for epithelial MHC-II-mediated immune surveillance in suppressing tumorigenesis. Finally, ISC-specific genetic ablation of MHC-II in engineered Apc-mediated intestinal tumor models increases tumor burden in a cell autonomous manner. These findings highlight how a HFD perturbs a microbiome – stem cell – immune cell crosstalk in the intestine and contributes to tumor initiation through the dampening of MHC-II expression in pre-malignant ISCs.
Project description:With annually 2.56 million deaths worldwide, pneumonia is one of the leading causes of death. Most frequent causative pathogens are Streptococcus pneumoniae and influenza A virus. Lately, the interaction between pathogens, the host and its microbiome gained more attention. A healthy microbiome is known to enhance the immune response towards pathogens, however, our knowledge on how infections affect the microbiome is still scarce. In this study, a meta-omics approach was used to investigate the impact of S. pneumoniae and influenza A virus infection on structure and function of the respiratory and gastrointestinal microbiomes of mice. In particular, the taxonomic composition of the respiratory microbiome was less affected by bacterial colonization and viral infection compared to S. pneumoniae infection. Pneumococcal pneumonia led to reduction of bacterial families and lower diversity in the respiratory microbiome, whereas diversity/richness was unaffected following H1N1 infection. Within the gastrointestinal microbiome we found exclusive changes in structure and function depending on the pneumonia inducing pathogen. Exemplarily, increased abundance of Akkermansiaceae and Spirochaetaceae, as well as decreased amounts of Clostridiaceae in response to S. pneumoniae infection, while increased presence of Enterococcaceae and Staphylococcaceae was specific for viral-induced pneumonia. Investigation of the intestinal microbiomes functional composition revealed reduced expression of flagellin and rubrerythrin and increased levels of ATPase during pneumococcal infection, while increased amounts of acetyl-CoA acetyltransferase and, enoyl-CoA transferase were unique after H1N1 infection. The identification of specific taxonomical and functional profiles during infection with a respective pathogen could deliver new insights in the role of the microbiome during disease and be beneficial for discrimination of pneumococcal- or viral-induced pneumonia.
Project description:With annually 2.56 million deaths worldwide, pneumonia is one of the leading causes of death. Most frequent causative pathogens are Streptococcus pneumoniae and influenza A virus. Lately, the interaction between pathogens, the host and its microbiome gained more attention. A healthy microbiome is known to enhance the immune response towards pathogens, however, our knowledge on how infections affect the microbiome is still scarce. In this study, a meta-omics approach was used to investigate the impact of S. pneumoniae and influenza A virus infection on structure and function of the respiratory and gastrointestinal microbiomes of mice. In particular, the taxonomic composition of the respiratory microbiome was less affected by bacterial colonization and viral infection compared to S. pneumoniae infection. Pneumococcal pneumonia led to reduction of bacterial families and lower diversity in the respiratory microbiome, whereas diversity/richness was unaffected following H1N1 infection. Within the gastrointestinal microbiome we found exclusive changes in structure and function depending on the pneumonia inducing pathogen. Exemplarily, increased abundance of Akkermansiaceae and Spirochaetaceae, as well as decreased amounts of Clostridiaceae in response to S. pneumoniae infection, while increased presence of Enterococcaceae and Staphylococcaceae was specific for viral-induced pneumonia. Investigation of the intestinal microbiomes functional composition revealed reduced expression of flagellin and rubrerythrin and increased levels of ATPase during pneumococcal infection, while increased amounts of acetyl-CoA acetyltransferase and, enoyl-CoA transferase were unique after H1N1 infection. The identification of specific taxonomical and functional profiles during infection with a respective pathogen could deliver new insights in the role of the microbiome during disease and be beneficial for discrimination of pneumococcal- or viral-induced pneumonia.