CME Evening – 15 August 2018

Gluten – the good, the bad, the ugly Dr Adele Melton MBChB, FRACP

Gluten . . . Bloated Sick Constipated Pain Reflux Dry skin Unwell Poor concentration Touch of dysentery

Overview What is gluten? Food science Gluten-related disorders Future developments

Wheat Major food crop, cultivated, consumed

Gluten Latin = “glue” Main storage protein of wheat grains Complex mixture of proteins Gliadin + glutenin

Act as a binding and extending agent Heat stable Act as a binding and extending agent Texture, moisture retention, flavour Baked products Other sources Bread - Processed meats Pasta - Reconstituted seafood Cakes - Seasoning, marinades Biscuits - Confectionary

Gliadin contains peptide sequences  resistant to gastric, pancreatic, intestinal proteolytic digestion in GI tract many proteases are unable to cleave high content of amino acids, proline and glutamine

Dietary intake Western diet Major source – wheat-containing bread 5 – 20g / day Major source – wheat-containing bread Slice = 4g gluten

(1) Coeliac disease 1% Western population Genetic predisposition Immune response  mucosal inflammation Resultant complications Malabsorption IDA, Osteoporosis Infertility Strict lifelong GFD

Gluten-free labelling FSANZ = “no detectable gluten” CODEX = up to 20 ppm gluten Future developments Blood tests Trials / Investigations Therapeutic vaccinations

(2) Wheat allergy IgE-mediated reaction Symptoms  minutes to hours after ingestion Itching, swelling, skin rash, anaphylaxis Baker’s asthma and rhinitis Atopic dermatitis and urticaria

(3) Non-coeliac gluten sensitivity NCGS or gluten-intolerance Symptoms with gluten ingestion Luminal and extra-luminal Possible explanations FODMAPs, changes in gut microbiota, altered serotonin 2 hit: gluten visceral sensitising, then poorly absorbing rapidly fermenting FODMAPs Unanswered questions All-or-none or dose-related phenomenon

Questions / Comments

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