Project description:HuMiChip was used to analyze human oral and gut microbiomes, showing significantly different functional gene profiles between oral and gut microbiome.
Project description:HuMiChip was used to analyze human oral and gut microbiomes, showing significantly different functional gene profiles between oral and gut microbiome. The results were used to demonstarte the usefulness of applying HuMiChip to human microbiome studies.
Project description:The migratory locust, Locusta migratoria, is a serious agricultural pest and important insect model to study insect digestion and feeding behavior. The gut is one of the primary interfaces between the insect and its environment. Nevertheless, knowledge on the gut transcriptome of L. migratoria is still very limited. With the development of two EST databases from L. migratoria (whole body and central nervous system (CNS)) and one EST database from Schistocerca gregaria (CNS), an abundance of transcript data was made available for locusts. In addition, the genome of Locusta was also recently published in an effort to create a better understanding of swarm formation and flight behavior (Wang et al., 2014). While the transcript composition of nervous tissue was relatively well studied after the development of the specific CNS-derived EST-databases from both L. migratoria and S. gregaria, little transcript profiling information is available for the digestive system at the moment. Locusts are, however, widely used as physiological model organisms regarding the regulation and control of feeding and digestion, and improved knowledge on the gut transcriptome could contribute significantly to a better understanding of their gut physiology. Therefore, we aimed to use the available sequence data to specifically identify gut-expressed transcripts in 5th larval locusts. By means of two independent self-self microarray hybridizations for two distinct tissues, the gut and the brain, a selection could be made of those ESTs that are present in the gut and/or the brain. Here, sequences that were found to be expressed in gut but not brain were further functionally annotated to shed new light on the complex physiology of the locust digestive system. Since the gut is the single most important organ in digestion, and both tissues are assumed to be involved in the regulation thereof, the resulting subset of sequences can also be valuable for further in-depth studies on the regulation of digestion. In addition, the method allowed us to rank the signal intensities, using them as a rough indicator to compare relative transcript abundance in the gut. Therefore, the data complement previously published transcript and genomic data, and provide a clear overview of the expressed portion of the genome in the gut. Taken together, the present data provide significant insight into locust larval gut physiology, and will be valuable for future studies on the insect gut. Self-self hybridisation of Cy5- and Cy3-labeled samples. One biological repeat per tissue type, i.e., brain and gut. Gut is a combination of foregut, midgut, gastric caeca and hindgut. Per tissue type, a pool was made from RNA from 3 pools of 5 locusts, and this for 3 different feeding conditions, resulting in samples derived from a total of 45 locust larvae. Feeding conditions were normally fed, fed with diet containing additional protease inhibitors (PIs), and starved locusts.
Project description:The diets of industrialized countries reflect the increasing use of processed foods, often with the inclusion of novel food additives. Xanthan gum is a complex polysaccharide with unique rheological properties that have established its use as a widespread stabilizer and thickening agent. Xanthan gum’s chemical structure is distinct from the host and dietary polysaccharides that are more commonly expected to transit the gastrointestinal tract, and little is known about its direct interaction with the gut microbiota, which plays a central role in digestion of other dietary fiber polysaccharides. Here, we show that the ability to digest xanthan gum is surprisingly common in industrialized human gut microbiomes and appears contingent on a single uncultured bacterium in the family Ruminococcaceae. Our data reveal that this primary degrader cleaves the xanthan gum backbone before processing the released oligosaccharides using additional enzymes. Surprisingly, some individuals harbor a Bacteroides intestinalis that is incapable of consuming polymeric xanthan gum but grows on oligosaccharide products generated by the Ruminococcaceae. Feeding xanthan gum to germfree mice colonized with a human microbiota containing the uncultured Ruminococcaceae supports the idea that this additive can drive expansion of this primary degrader along with exogenously introduced Bacteroides intestinalis. Our work demonstrates the existence of a potential xanthan gum food chain involving at least two members of different phyla of gut bacteria and provides an initial framework to understand how widespread consumption of a recently introduced food additive influences human microbiomes.
Project description:Although gut microbiomes are generally symbiotic or commensal, some of microbiomes become pathogenic under certain circumstances, which is one of key processes of pathogenesis. However, the factors involved in these complex gut-microbe interactions are largely unknown. Here we show that bacterial nucleoside catabolism using gut luminal uridine is required to boost inter-bacterial communications and gut pathogenesis in Drosophila. We found that uridine-derived uracil is required for DUOX-dependent ROS generation on the host side, whereas uridine-derived ribose induces quorum sensing and virulence gene expression on the bacterial side. Importantly, genetic ablation of bacterial nucleoside catabolism is sufficient to block the commensal-to-pathogen transition in vivo. Furthermore, we found that major commensal bacteria lack functional nucleoside catabolism, which is required to achieve gut-microbe symbiosis. The discovery of a novel role of bacterial nucleoside catabolism will greatly help to better understand the molecular mechanism of the commensal-to-pathogen transition in different contexts of host-microbe interactions.
2020-04-07 | GSE140194 | GEO
Project description:Wild pedigrees inform mutation rates and historic abundance in baleen whales
Project description:We systematically investigated the responses of five human gut microbiomes to 21 common sweeteners, using an approach combining high-throughput ex vivo microbiome culturing and metaproteomics to quantify functional changes in different taxa. Hierarchical clustering based on metaproteomic responses of individual microbiomes resulted in two clusters. The first cluster was composed of non-caloric artificial sweeteners (NAS) and two sugar alcohols with shorter carbon backbones (4-5 carbon atoms), and the second cluster was composed of sugar alcohols with longer carbon backbones. The metaproteomic functional responses of the second cluster were similar to the prebiotic fructooligosaccharides and kestose, indicating that these sugar alcohol-type sweeteners have potential prebiotic functions.