Polysaccharide production and degradation by bacteria in food and gastrointestinal systems

点击翻译按钮获取中文摘要

The long-term aim of this research is to understand the dynamics of microbial communities in food and the gastrointestinal tract through the modulation of polysaccharide production and degradation. The first theme will investigate the biosynthetic mechanisms determining the molecular mass of exopolysaccharides (EPS) with the aim of manipulating EPS size distribution for testing in food and gut ecosystems. The effect of environmental conditions on gene expression will be examined using comparative transcriptomics. This will help determine the optimal conditions necessary for EPS biosynthesis in food processes, while suggesting how EPS production may change through the digestive system. Gene editing will help show how protein phosphorylation regulates protein function. In the second theme, interactions between probiotics and foodborne pathogens in the gut ecosystem will be investigated. This work will provide experimentally testable hypotheses about pathogen exclusion and gut microbiome community stability in the third theme. In this theme, the fitness of potential probiotic strains and food pathogens for competition or cooperation in the gastrointestinal tract will be assessed using the Simulator of the Human Intestinal Microbial Ecosystem. Selective enrichment using fibre substrates of discrete molecular mass will facilitate the evaluation of strains and prebiotic combinations. Furthermore, the role of EPS production by probiotics and food pathogens in colonisation of the mucosal interface will be explored. Understanding gene function and regulation in probiotic and lactic acid bacteria is essential for improving the selection of yogurt and cheese starter microorganisms, as well as for food safety and developing functional foods that have a beneficial impact on human health. The significance of this research is understanding how food structure and composition impact digestion from a microbial ecology perspective. Diet plays a crucial role in microbial community composition and activity, so comprehension of how food formulation impacts this ecosystem will help to improve food quality. With this knowledge, more effective targeting of prebiotic ingredients will be possible for attaining the desired impact on the metabolic activity of gut microbiota and preventing foodborne infections. Fostering expertise to predict responses to specific foods, depending on microbiota composition, has the potential to open up the prospect of personalised dietary approaches. This research can lead to the production of novel foods, functional foods and supplements, as well as a better understanding of gut microbe community regulation through food. For industry, the results can be applied to developing innovative ways to add value to dairy processing co-products such as whey, which will contribute to reducing food waste.