Project description:Mandarin fish Siniperca chuatsi (Basilewsky) (Percichthyidae), as a demersal piscivore, has very specialized feeding habits, for as soon as they start feeding the fry of this fish feed solely on fry of other fish species. In rearing conditions, mandarin fish has been found to accept live prey fish only, and refuse dead prey fish or artificial diets, very little is currently known about the molecular mechanisms of multiple genes which cover different pathways influencing the specialized food habit, such as live prey. We performed transcriptome comparisons between dead prey fish feeders and nonfeeders in mandarin fish. The determination mechanisms of specialized food habit (live prey fish) in mandarin fish could provide some instructions for research of food habit in animals, including mammals.
Project description:Beneficial modulation of the gut microbiome has high-impact implications not only in humans, but also in livestock that sustain our current societal needs. In this context, we have engineered an acetylated galactoglucomannan (AcGGM) fibre from spruce trees to match unique enzymatic capabilities of Roseburia and Faecalibacterium species, both renowned butyrate-producing gut commensals. The accuracy of AcGGM was tested in an applied pig feeding trial, which resolved 355 metagenome-assembled genomes together with quantitative metaproteomes. In AcGGM-fed pigs, both target populations differentially expressed AcGGM-specific polysaccharide utilization loci, including novel, mannan-specific esterases that are critical to its deconstruction. We additionally observed a “butterfly effect”, whereby numerous metabolic changes and interdependent cross-feeding pathways were detected in neighboring non-mannolytic populations that produce short-chain fatty acids. Our findings show that intricate structural features and acetylation patterns of dietary fibre can be customized to specific bacterial populations, with the possibility to create greater modulatory effects at large.
Project description:Eating habits are closely related to the body's nutrient absorption and metabolic homeostasis. In order to better reveal the changes of intestinal epithelial cells under different dietary patterns, we examined the changes of gene expression profiles in jejunal epithelial cells of mice after 10 days of breakfast skipping feeding pattern by RNA sequencing.
Project description:Bifidobacteria are among the earliest colonizers of the human gut and are widely used as probiotics for their health-promoting properties. However, individual responses to probiotic supplementation may vary with strain type(s), microbiota composition, diet, or lifestyle conditions, highlighting the need for strain-level insight into bifidobacterial carbohydrate metabolism. Here, we systematically reconstructed 68 pathways involved in the utilization of mono-, di-, oligo-, and polysaccharides by analyzing the distribution of 589 curated metabolic functional roles (catabolic enzymes, transporters, transcriptional regulators) in 3083 non-redundant cultured Bifidobacterium isolates and metagenome-assembled genomes (MAGs) of human origin. Our analysis uncovered extensive inter- and intraspecies heterogeneity, including a distinct clade within the Bifidobacterium longum species capable of metabolizing starch. We also identified isolates of Bangladeshi origin that harbor unique gene clusters implicated in the breakdown of xyloglucan and human milk oligosaccharides. Thirty-eight predicted carbohydrate utilization phenotypes were experimentally validated in 30 geographically diverse Bifidobacterium isolates in vitro. Our large-scale genomic compendium expands the knowledge of bifidobacterial carbohydrate metabolism and can inform the rational design of probiotic and synbiotic formulations tailored to strain-specific nutrient preferences.