IMPACTS OF FOOD ON INTESTINAL FUNCTION & HEALTH - - PowerPoint PPT Presentation

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) ¡

+ ¡several ¡farms ¡around ¡NZ ¡ AgResearch ¡Grasslands ¡ Palmerston ¡North ¡     

AGRESEARCH ¡SCIENCE ¡STRUCTURE ¡

CEO Tom Richardson

GM – Food & Textiles Warren McNabb

Animal Health Bio-based Products & Textiles Rumen Nutrition & Microbiology

GM – Applied Biotechnologies Jimmy Suttie

Forage Biotechnology Animal Improvement Animal Biosciences Bioinformatics, Mathematics & Statistics Forage Improvement

GM – Agriculture & Environment Peter Benfell

Biocontrol & Biosecurity Agricultural Systems Climate, Land & Environment Agri-Foods & Health Greenhouse Gas Research Centre

NutriLon ¡ Chemistry ¡ Microbiology ¡ Metabolism ¡

AgResearch’s Systems Biology Platform

Proteomics ¡ Metabolomics ¡ PlaNorm ¡ FuncLonal ¡(Epi) genomics ¡ PlaNorm ¡ BioinformaLcs ¡ MathemaLcs ¡ Modelling ¡ PlaNorm ¡ Meat ¡Science ¡ Food ¡Safety ¡

Food Nutrition Genomics 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

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

FOOD ¡NUTRITION ¡GENOMICS ¡TEAM ¡

The intestinal tract is a highly complex system – food/ microbe/mucosal interface

Human intestinal mucosa

• Largest interface (barrier) between

humans and the environment.

• Critical for the balance between

health and disease.

• Crucial to food utilisation; poor

function linked to diet-related diseases. >25,000 food components Foods can affect:

• probiotic bacterial growth
• immune system balance
• 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

• f body.

Physical ¡barrier ¡

(the ¡epithelium) ¡

Chemical ¡barrier ¡

(mucus ¡layer) ¡

Immunological ¡ barrier ¡

(immune ¡cells ¡of ¡the ¡ lamina ¡propria) ¡

Microbial ¡barrier ¡

(commensal ¡bacteria) ¡

Hooper LV (2009) Nat Rev Microbiol. 7(5):367-74.

Muscle ¡layers ¡ ¡

(smooth ¡muscle ¡gut ¡wall) ¡

• Intestinal muscle assay
• Fluorescence-based cellular assay
• Intestinal permeability assay
• Patch-clamping

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 ¡SMOOTH ¡MUSCLE ¡

Intestinal contraction is determined by circular and longitudinal muscle layers and affected by neuronal inputs

ORAL

NEUROMOTOR ¡FUNCTION ¡

Interneuron Longitudinal muscle motor neuron Circular muscle motor neuron Interneuron Network of neurons ANAL

• Measures effects of intestinal contents on smooth muscle

contractility

• Provides information on whether intestinal contractility is affected.

INTESTINAL ¡MUSCLE ¡ASSAY ¡

Contraction force Control Test condition Control Time

• 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), between cells, or both (TEER).

FLUORESCENCE-BASED CELLULAR ASSAY ¡

apical basolateral

Cl K Na 2Cl K K 2K

AT P

3N a Cl K Na 2Cl K K 2K

AT P

3N a

• TEER measures changes in tight junction

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).

• The results indicate improved (increased

resistance) or weakened (decreased resistance) epithelial barrier function by bacteria (food ingredients could also be used).

TRANS-EPITHELIAL ELECTRICAL RESISTANCE ASSAY (TEER) ¡

Control Strain 1 Strain 2

bacteria added

ION ¡CHANNELS ¡IN ¡THE ¡CELL ¡MEMBRANE ¡

cellular excitability muscle contraction, neuronal firing and neurotransmitter release intestinal motility cellular permeability ion and water absorption/secretion faecal moisture faecal consistency (diarrhoea/constipation)

• microbial balance
• enteric nervous system
• immune system

Patch-clamping of cells to directly measure ionic currents across cell membranes as ion channels open and close.

ELECTROPHYSIOLOGY ¡

Express protein Identify cell Record current

Patch-clamp data example of an inhibitory effect measured for a K+ ion channel

ELECTROPHYSIOLOGY ¡

Dose response relationship control test condition recovery Provides specific information on how 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

AgResearch ¡ Grasslands ¡ Palmerston ¡North ¡

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