IMPACTS ¡OF ¡FOOD ¡ON ¡ ¡ INTESTINAL ¡FUNCTION ¡& ¡HEALTH ¡ JULIE ¡DALZIEL, ¡ SENIOR ¡RESEARCH ¡SCIENTIST, ¡ FOOD ¡NUTRITION ¡GENOMICS ¡ AGRI-‑FOODS ¡& ¡HEALTH ¡ TOKYO, ¡12 ¡OCTOBER ¡2010 ¡
AGRESEARCH ¡ NZ’s largest Crown Research Institute • Wholly government-owned • 860 full-time equivalent staff (250 PhDs) Research and development funding • 45% revenue from competitive grants • 55% revenue from commercial contracts • Total annual revenue (08/09): NZ$ 148m • Small amount of direct Government funding Research and development scope • From “paddock to the plate” • Basic and applied research
OUR ¡FOCUS ¡ Raise productivity in the NZ pastoral sector in an environmentally sustainable manner. Introduce a range of biotechnologies and other technologies to NZ. Export our own biotechnologies and other technologies to the world.
AGRESEARCH ¡SITES: ¡ Ruakura ¡ (Hamilton) ¡ Grasslands ¡ (Palmerston ¡North) ¡ Wallaceville ¡ (Wellington) ¡ Lincoln ¡ (Christchurch) ¡ Invermay ¡ (Dunedin) ¡ AgResearch ¡Grasslands ¡ Palmerston ¡North ¡ + ¡several ¡farms ¡around ¡NZ ¡
AGRESEARCH ¡SCIENCE ¡STRUCTURE ¡ CEO Tom Richardson GM – Food & Textiles GM – Applied Biotechnologies GM – Agriculture & Environment Warren McNabb Jimmy Suttie Peter Benfell Biocontrol & Biosecurity Animal Improvement Agri-Foods & Health Agricultural Systems Animal Biosciences Rumen Nutrition & Bioinformatics, Climate, Land & Microbiology Mathematics & Statistics Environment Bio-based Products & Textiles Forage Improvement Animal Health Forage Biotechnology Greenhouse Gas Research Centre
NutriLon ¡ Meat ¡Science ¡ Food ¡Safety ¡ Chemistry ¡ Metabolism ¡ FuncLonal ¡(Epi) genomics ¡ PlaNorm ¡ Microbiology ¡ BioinformaLcs ¡ Proteomics ¡ MathemaLcs ¡ Metabolomics ¡ Modelling ¡ PlaNorm ¡ PlaNorm ¡ AgResearch’s Systems Food Nutrition Genomics Biology Platform Dairy Foods Food Microbiology & Safety Meat Science & Technology
DAIRY ¡FOODS ¡-‑ ¡PROTEIN ¡PURIFICATION ¡ Purification of proteins and milk fractions • lab-scale (mg to gram quantities) • pilot-scale (gram to kg) Anti-fungal, anti-viral, anti-bacterial e.g. nutraceutical food, crop protection, food preservative (Smolenski et al., 2007, J Proteome Res 6: 207-15) Immune-modulating e.g. nutraceutical food Enzymes for flavour development e.g. kokumi Mold growing on food and crop products
FOOD ¡NUTRITION ¡GENOMICS ¡TEAM ¡ Team Leader • Dr Nicole Roy Team composition • 12 scientists • 8 technicians • 11 PhD students Core capabilities • Functional genomics • Microbiology • Cell/tissue bioassays & electrophysiology • Animal models Core areas of research • Food, host and microbial interactions • Molecular Nutrition (nutritional genomics, epigenomics, metabolomics) • Neuromotor function and membrane physiology
The intestinal tract is a highly complex system – food/ microbe/mucosal interface >25,000 food components Human intestinal mucosa • Largest interface (barrier) between humans and the environment. • Critical for the balance between health and disease. Foods can affect: • Crucial to food utilisation; poor • probiotic bacterial growth function linked to diet-related • immune system balance diseases. • intestinal barrier function • intestinal motility
What is intestinal barrier function? Intestinal barrier separates intestinal lumen from underlying tissue and provides a protective interface between internal and external environment of body. Microbial ¡barrier ¡ (commensal ¡bacteria) ¡ Chemical ¡barrier ¡ (mucus ¡layer) ¡ Physical ¡barrier ¡ (the ¡epithelium) ¡ Immunological ¡ barrier ¡ (immune ¡cells ¡of ¡the ¡ lamina ¡propria) ¡ Muscle ¡layers ¡ ¡ (smooth ¡muscle ¡gut ¡wall) ¡ Hooper LV (2009) Nat Rev Microbiol. 7(5):367-74.
CELL ¡& ¡TISSUE ¡BIOASSAYS ¡ Techniques to measure changes in cell and tissue function in response to food/pharmaceuticals and therefore predict human health outcomes and detect unwanted gastrointestinal side effects. Intestinal muscle assay Fluorescence-based cellular assay Intestinal permeability assay Patch-clamping
NEUROMOTOR ¡FUNCTION ¡ Longitudinal Circular muscle muscle Interneuron motor neuron motor neuron ANAL ORAL Interneuron Network of neurons INTESTINAL ¡SMOOTH ¡MUSCLE ¡ Intestinal contraction is determined by circular and longitudinal muscle layers and affected by neuronal inputs
INTESTINAL ¡MUSCLE ¡ASSAY ¡ Measures effects of intestinal contents on smooth muscle contractility Control Test condition Contraction force Control Time Provides information on whether intestinal contractility is affected.
FLUORESCENCE-BASED CELLULAR ASSAY ¡ Indirectly measure changes in membrane permeability by detecting changes in membrane potential or intracellular calcium. Provides general information on whether receptor/ion channel mechanisms are affected Permeability measured across the cell membrane (fluoresense, patch-clamp), apical between cells, or both (TEER). Cl K Cl K K K 3N 3N a a AT AT P P Na 2K Na 2K K K 2Cl 2Cl basolateral
TRANS-EPITHELIAL ELECTRICAL RESISTANCE ASSAY (TEER) ¡ bacteria TEER measures changes in tight junction added resistance across an epithelial Caco-2 cell monolayer using an ohmmeter Example shows a control, a bacterial strain that decreases epithelial resistance (strain 2), and another that increases resistance (strain 1). Control Strain 1 Strain 2 The results indicate improved (increased resistance) or weakened (decreased resistance) epithelial barrier function by bacteria (food ingredients could also be used).
ION ¡CHANNELS ¡IN ¡THE ¡CELL ¡MEMBRANE ¡ cellular permeability cellular excitability muscle contraction, neuronal ion and water firing and neurotransmitter absorption/secretion release faecal moisture intestinal motility faecal consistency (diarrhoea/constipation) - microbial balance - enteric nervous system - immune system
ELECTROPHYSIOLOGY ¡ Patch-clamping of cells to directly measure ionic currents across cell membranes as ion channels open and close. Express protein Identify cell Record current
ELECTROPHYSIOLOGY ¡ Patch-clamp data example of an inhibitory effect measured for a K+ ion channel control test condition recovery Dose response Provides specific information on how relationship receptor/ion channel mechanisms are affected. Dalziel et al . 2005, Toxicology Letters 155: 421-6.
RELEVANT ¡PUBLICATIONS ¡
COLLABORATORS ¡ NZ: Auckland University, Liggins (Auckland), Plant & Food Research, Otago University (Dunedin), Massey University Riddet Institute (Palmerston North). International: A/Prof Andrea Meredith, University of Maryland – K+ channel knockout mice Prof Shunyi Zhu, Chinese Academy of Sciences – K+ channel inhibitors Dr Yue-kun Ju, University of Sydney – Cardiac ion channels Prof Richard Aldrich, University of Texas – Ion channel research Prof Kikuji Itoh, Tokyo University – Germ-free rodents. Prof Jeremy Wells, Wageningen University – Intestinal barrier function. Prof Ian Rowland, Reading University – Molecular nutrition/cancer. Prof Jonathan Powell, Cambridge University – Nanoparticles.
COLLABORATIVE ¡OPPORTUNITIES ¡ Protein purification Test effects of food ingredients on intestinal function, including motility and effects on receptors and ion channels Explore underlying mechanisms of action We invite you to visit us in NZ! AgResearch ¡ Grasslands ¡ Palmerston ¡North ¡
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