Obesity is one of the fastest growing medical issues across the western world and it is fast becoming one of the leading causes of mortality worldwide. At least one in thirteen annual deaths in the European Union are likely to be related to overweight. That is 337,000 deaths/year and Britain leads the E.U. table of deaths related to excess body weight. Half the adults in the U.K. are overweight and around one in four is obese. Obesity increases the risk of high blood pressure, heart disease and late onset diabetes with an estimated cost to the economy of £2 Billion/year. In general, women have a greater body mass index (BMI) distribution and higher obesity rate compared to men. Obesity is a condition associated with poverty and a poor diet in both the developed and developing nations. It is therefore particularly important that if treatment/prevention is delivered via diet that the foods should be affordable and acceptable e.g. bread, the vehicle we intend to trial. Because eating is a pleasurable experience and humans tend to over eat if food is available in excess, in particular high energy foods which are often rich in fat. Reducing fat metabolism and uptake is one approach to reducing weight gain. Therefore chemically synthesised inhibitors of the fat digesting enzymes, lipases are currently being used to treat obesity. At present the major lipase inhibitor available on prescription in the U.K. is orlistat (Xenical) which will reduce fat absorption by up to 30%. However side effects such as oily stools, flatulence and diarrhoea have meant reduced acceptability. Interestingly these side effects can be significantly reduced if the lipase inhibitor is taken with a dietary fibre supplement. Therefore a good solution would be a dietary fibre with lipase inhibitory activity. Alginate, a natural fibre from seaweed has these properties. We have demonstrated in our lab that alginates have a similar ability to inhibit lipase as orlistat. We therefore aim to screen a bank of alginates (over 20), some of which are already used in the food industry at low levels and other naturally occurring biopolymers to determine the best lipase inhibitor profile using a lab based colorimetric assay. Using the best inhibitors we will demonstrate their ability to inhibit lipase activity in conditions as close as possible to those in the gut, i.e. with other food components etc. The best candidate/s from the above studies will then be tested (delivered in bread in the first instance) in human volunteers. A group of healthy subjects will be used to determine acceptability of the biopolymer in the food vehicle and to determine the best balance between lipase inhibition and levels of biopolymer intake. Our preliminary studies showed no acceptability problems with alginate levels as high as 10% by weight in bread. Following the studies with the healthy subjects the biopolymer enriched foods will be tested to demonstrate calorific intake reduction in ileostomy patients. This study has the potential to provide evidence that normal foods supplemented with fibre biopolymers can be used to treat obesity/overweight and allow this to be translated by the food industry into the development of a range of other tasty and affordable food products. Such a range would have the potential to reduce calorific intake, as well as include the health benefits of dietary fibre.

Pepsins as biomarkers Intermittent reflux of gastric juice into the oesophagus and beyond is a normal physiological event. Consequently tissues such as the oesophagus, larynx, nasopharynx and airways must have mechanisms of mucosal protection in place. Currently attempts to measure reflux in humans use invasive diagnostic tools such as 24 hour pH monitoring or impedance measurement, both techniques involve placing a thin walled tube through the nostril into the oesophagus for a distance of about 45 cm. Therefore in order to determine reflux levels a biomarker needs to be identified and quantified. Pepsins, a major enzyme component of gastric juice (present at 0.2-1mg/ml) are such biomarkers. The aims of this project are two fold; (1) To define the normal levels of reflux and develop a simple assay system for pepsin that can be developed commercially. (2) To characterise tissue specific protection mechanisms. At present no commercial assay is available to measure pepsin in biological fluids and tissues and a central part of this study will be to develop such an assay with Prof Pearson at Newcastle University and Technostics, an SME based in Kingston upon Hull, East Yorkshire. To date there is little or no information in the literature to define the normal levels of reflux or the protective mechanisms present in these tissues. Mucus, bicarbonate, differential expression of carbonic anhydrase isoenzymes, stress proteins and cell adhesion molecules have all been implicated. In ICaMB at Newcastle University the student will use in vitro cell and explant culture techniques to investigate the effects of pepsin on mucosal integrity in the oesophagus, larynx, nasopharynx and the airways. Techniques employed will include immunohistochemistry, quantitative PCR, ELISA and multiplex techniques to measure mucins, carbonic anhydrase isoenzymes, epithelial stress proteins and cell adhesion molecules. While at Technostics the student will be trained in all aspects of commercial assay development including antibody design using computer programs to identify key epitopes within the pepsin protein; monoclonal antibody production; lateral flow dipstick technology. Assay development including assessing reproducibility, reliability and ease of use in the clinical setting will be carried out at both Technostics and Newcastle University. This will involve the student interacting with industrial and clinical colleagues. Thus the student will be exposed to a wide range of techniques in commercial and academic environments. This pepsin assay when fully developed and validated will identify reflux events by the appearance of pepsin in sputum expectorated by the subject and in a dip stick format could be used in the doctors surgery. It will also have applications in disease diagnosis and directing treatment management, where excessive reflux can lead to tissue damage in the aero-digestive tract. The need for such an assay is well demonstrated by the recent identification of health problems associated with reflux. We and others have demonstrated reflux of gastric juice is implicated in the development of several upper airway diseases e.g. rhinitis, sinusitis, otitis media with effusion, voice disorders, globus and laryngeal cancer and several lung diseases e.g. asthma and COPD. We have recently demonstrated a key role for reflux in lung transplant rejection. Consequently understanding the nature of the refluxate and how tissues defend themselves are critical questions. Also medical practise is crying out for a simple, easy to use diagnostic tool for reflux.