Project description:Symbiotic bacteria inhabiting the distal human gut have evolved under intense pressure to utilize complex carbohydrates, predominantly plant cell wall glycans abundant in our diets. These substrates are recalcitrant to depolymerization by digestive enzymes encoded in the human genome, but are efficiently targeted by some of the ~103-104 bacterial species that inhabit this niche. These species augment our comparatively narrow carbohydrate digestive capacity by unlocking otherwise unusable sugars and fermenting them into host-absorbable forms, such as short-chain fatty acids. We used phenotype profiling, whole-genome transcriptional analysis and molecular genetic approaches to investigate complex glycan utilization by two fully sequenced and closely related human gut symbionts: Bacteroides thetaiotaomicron and Bacteroides ovatus. Together these species target all of the common glycosidic linkages found in the plant cell wall, as well as host polysaccharides, but each species exhibits a unique ‘glycan niche’: in vitro B. thetaiotaomicron targets plant cell wall pectins in addition to linkages contained in host N- and O-glycans; B. ovatus uniquely targets hemicellulosic polysaccharides along with several pectins, but is deficient in host glycan utilization. Bacteroides ovatus bacteria were grown either in vitro on defined complex glycan sources, or in vivo in the intestinal tract of gnotobiotic mice fed variable diets. Increased in vitro gene expression was used to indicate the genes required for metabolism of complex glycans and compared to in vivo transcriptional activity to determine expression in the mouse gut.
Project description:Allogeneic hematopoietic stem cell transplantation remains the most efficacious treatment for many hematological malignancies. However, its therapeutic potential is affected by the most prominent side effect graft versus host disease. Despite advances in the treatment of graft versus host disease in recent years, morbidity and mortality remains high, which requires the development of new treatment approaches. We therefore implemented mouse models to assess potential treatment options for graft versus host disease. In in vivo experiments, we had observed a protective effect of LCN2 on graft versus host disease of the gastrointestinal tract. We also observed higher numbers of anti-inflammatory macrophages in the intestinal tissues of these animals. Therefore, we aimed to determine potentially regulated genes in these cells by using an in vitro approach of LCN2-treated macrophages.
Project description:RATIONALE: Beclomethasone may be an effective treatment for graft-versus-host disease.
PURPOSE: Phase I/II trial to study the effectiveness of beclomethasone in treating patients who have graft-versus-host disease of the esophagus, stomach, small intestine, or colon.
| 2005776 | ecrin-mdr-crc
Project description:Mucus-degrating Bacteroides link carbapenem antibiotics to aggravated graft-versus-host-disease
| PRJNA858489 | ENA
Project description:Mucus-degrating Bacteroides link carbapenem antibiotics to aggravated graft-versus-host-disease,
Project description:The effect of tauroursodeoxycholic acid on the development of acute graft-versus-host disease was tested in a murine allogeneic stem cell transplantation model. TUDCA was shown to reduce acute GVHD by reducing intestinal antigen presentation and following apoptosis and increasing the viability of intestinal epithelial cells.
Project description:Symbiotic bacteria inhabiting the distal human gut have evolved under intense pressure to utilize complex carbohydrates, predominantly plant cell wall glycans abundant in our diets. These substrates are recalcitrant to depolymerization by digestive enzymes encoded in the human genome, but are efficiently targeted by some of the ~103-104 bacterial species that inhabit this niche. These species augment our comparatively narrow carbohydrate digestive capacity by unlocking otherwise unusable sugars and fermenting them into host-absorbable forms, such as short-chain fatty acids. We used phenotype profiling, whole-genome transcriptional analysis and molecular genetic approaches to investigate complex glycan utilization by two fully sequenced and closely related human gut symbionts: Bacteroides thetaiotaomicron and Bacteroides ovatus. Together these species target all of the common glycosidic linkages found in the plant cell wall, as well as host polysaccharides, but each species exhibits a unique ‘glycan niche’: in vitro B. thetaiotaomicron targets plant cell wall pectins in addition to linkages contained in host N- and O-glycans; B. ovatus uniquely targets hemicellulosic polysaccharides along with several pectins, but is deficient in host glycan utilization. Growth of Bacteroides thetaiotaomicron in vitro in minimal medium plus different purified complex glycans. Observation of increased gene expression was used to determine genes that are involved in metabolism of each glycan. Two biological replicates each.