Gut microbiota and sirtuins in obesity-related inflammation and bowel dysfunction

Obesity is a chronic disease characterized by persistent low-grade inflammation with alterations in gut motility. Motor abnormalities suggest that obesity has effects on the enteric nervous system (ENS), which controls virtually all gut functions. Recent studies have revealed that the gut microbiota can affect obesity and increase inflammatory tone by modulating mucosal barrier function. Furthermore, the observation that inflammatory conditions influence the excitability of enteric neurons may add to the gut dysfunction in obesity. In this article, we discuss recent advances in understanding the role of gut microbiota and inflammation in the pathogenesis of obesity and obesity-related gastrointestinal dysfunction. The potential contribution of sirtuins in protecting or regulating the circuitry of the ENS under inflamed states is also considered

Microscreening toxicity system based on living magnetic yeast and gradient chips

There is an increasing demand for easy and cost-effective methods to screen the toxicological impact of the growing number of chemical mixtures being generated by industry. Such a screening method has been developed using viable, genetically modified green fluorescent protein (GFP) reporter yeast that was magnetically functionalised and held within a microfluidic device. The GFP reporter yeast was used to detect genotoxicity by monitoring the exposure of the cells to a well-known genotoxic chemical (methyl methane sulfonate, MMS). The cells were magnetised using biocompatible positively charged PAH-stabilised magnetic nanoparticles with diameters around 15 nm. Gradient mixing was utilised to simultaneously expose yeast to a range of concentrations of toxins, and the effective fluorescence emitted from the produced GFP was measured. The magnetically enhanced retention of the yeast cells, with their facile subsequent removal and reloading, allowed for very convenient and rapid toxicity screening of a wide range of chemicals. This is the first report showing magnetic yeast within microfluidic devices in a simple bioassay, with potential applications to other types of fluorescent reporter yeast in toxicological and biomedical research. The microfluidic chip offers a simple and low-cost screening test that can be automated to allow multiple uses (adapted to different cell types) of the device on a wide range of chemicals and concentrations