Dr Peter Ellis
Diabetes & Nutritional Sciences Division
School of Medicine
King's College London
4.102 Franklin-Wilkins Building
150 Stamford Street
London SE1 9NH
Tel: +44 (0)20 7848 4238
Fax: +44 (0)20 7848 4171
Specific interest in the functionality of dietary polysaccharides (starch and non-starch polysaccharides or NSP) with respect to the bioavailability of nutrients and prevention and treatment of disease (e.g. diabetes, coronary heart disease, arthritis). Much of the work focuses on the rheological behaviour of water-soluble NSP in the gastrointestinal tract and also the properties of supramolecular structures (starch, plant cell walls), particularly in relation to the kinetics of nutrient absorption (e.g. glucose) and the so called 'glycaemic index'. A unique aspect of this work is the multi-disciplinary mechanistic approach to:
understanding the role of dietary polysaccharides in the prevention and treatment of disease (More specifically, this has involved investigating polysaccharide function in relation to gastrointestinal (GI) events, such as the physico-chemical processes that influence carbohydrate digestion and absorption. This is of considerable importance in evaluating the role of starch and non-starch polysaccharides ("dietary fibre") in the aetiology and treatment of disease, such as diabetes, hyperlipidaemia and cancer.
developing 'functional foods' with enhanced medical or nutritional benefits.
One major project has been to investigate the physico-chemical mechanisms underlying the effects of dietary non-starch polysaccharides (NSP) on glucose absorption and the secretion of insulin and hormones of the enteroinsular axis. An important part of this work has been the application of rheological methods to studies of the behaviour of biologically-active non-starch polysaccharides in vitro and in vivo (the latter using the pig as an animal model and ileostomy patients). A closely-linked project funded deals with other food-related factors that are likely to influence the rate and extent of starch digestion in the GI tract.
Collaborators: Dr Linda Morgan (University of Surrey), Prof Nick Read (University of Sheffield), Dr Janet Tomlin (Royal Hallamshire Hospital, Sheffield) and Dr Peter Wood (Agriculture Canada, Ottawa).
This work has been funded by the BBSRC, MAFF and Industry.
Studies of the characterisation of the structure and properties of new sources of NSP (e.g. molecular weight, solution rheology) from plant and microbial sources. We have recently shown that one of these, a xyloglucan extracted from a leguminous African plant food (Detarium senegalense Gmelin), has considerable promise in the treatment of diabetes and hyperlipidaemia. Its properties also indicate it has considerable commercial potential in the food, drugs and chemical industries. Other studies have focused on the hydration kinetics in vitro and in vivo of NSP and the effects of particulate material on the solution rheology of NSP, both of which are crucial aspects of the biological activity of these polymers.
Collaborators: Prof. Edwin Morris (Silsoe College), Prof. Ian Sutherland (University of Edinburgh).
This work has been funded by Industry.
One important application of the mechanistic and characterisation work described briefly above, is in the development and clinical testing of so-called "functional" foods for the dietary management of diabetes mellitus and hyperlipidaemia. This has involved carrying out acute and long-term clinical trials in diabetic and hyperlipidaemic individuals to test the efficacy of fibre-supplemented foods.
Collaborators: Dr Peter Frost (Central Middlesex Hospital, London) and Dr Peter Wood (Agriculture Canada, Ottawa).
This work has been funded by Industry and British Diabetic Association.
Other project include a study of the "nutritional status of fermented cereal foods in ancient Egyptian diet" in collaboration with Drs Delwen Samuel and Gordon Hill of the Institute of Archaeology, UCL. One aspect of this work is to study the physico-chemical properties of foods and food components in relation to their bioavailability and nutritional properties (Financial support from the Wellcome Trust).
Tahir, R., Ellis, P.R. and Butterworth, P.J. (2010) The relation of physical properties of native starch granules to the kinetics of amylolysis catalysed by porcine pancreatic a-amylase. Carbohydr. Polym. 81, 57-62.
Roder, N., Gerard C., Verel A., Bogracheva T.Y., Hedley C.L., Ellis P.R. and Butterworth P.J. (2009) Factors affecting the action of a-amylase on starch: Effects of water availability and the presence of sucrose. An enzymic and structural study. Food Chemistry 113, 471-478.
Wang, Q., Ellis, P.R. and Ross-Murphy, S.B. (2008) Dissolution kinetics of water soluble polymers – the guar gum paradigm. Carbohydr. Polym. 74, 519-526.
Mandalari, G., Faulks, R.M., Rich, G.T., Turco, V.L., Picout, D.R., Curto, R.B.L., Bisignano, G., Dugo, D., Dugo, G., Waldron, K.W., Ellis, P.R. and Wickham, M.J.S. (2008) ) Release of protein, lipid and vitamin E from almond seeds during digestion. J. Agric. Food Chem. 56, 3409-3416.
Berry, S.E.E., Tydeman, E.A., Lewis, H.B., Phalora, R., Rosborough, J., Picout, D.R. and Ellis, P.R. (2008) Manipulation of lipid bioaccessibility of almond seeds influences postprandial lipemia in healthy human subjects. Am. J. Clin. Nutr. 88, 922-929.
Wang, Q., Ellis, P.R. and Ross-Murphy, S.B. (2006) Dissolution kinetics of guar gum powders – III. Effect of particle size. Carbohydr. Polym 64, 239-246.
Ren, Y., Picout D.R. Ellis, P.R., Ross-Murphy S.B. and Reid, J.S.G. (2005) A novel xyloglucan from seeds of Afzelia africana Se. Pers.– extraction, characterisation and conformational properties. Carbohydr. Res. 340, 997-1005.
Ren, Y., Picout D.R. Ellis, P.R. and Ross-Murphy S.B. (2004) Solution properties of the xyloglucan polymer of Afzelia africana. Biomacromolecules 5, 2384-2391.