Resistant starch, food structure and the gut microbiota: new...
Transcript of Resistant starch, food structure and the gut microbiota: new...
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Resistant starch, food structure and the gut microbiota: new insights Dr. Fred Warren, Research Leader
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What is starch? And what makes it resistant?
• Starch is a key component in the human diet, and our main source of energy
• It is a complex carbohydrate , which is broken down during digestion to release glucose
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What is starch? And what makes it resistant?
• A proportion escapes digestion a reaches the colon, where it is available to be fermented by gut bacteria
• Bacterial fermentation of carbohydrate has many health benefits
http://www.cpe.sk/ka-izvairities-no-gremosanas-sistemas-traucejumiem/
• Not all of the starch that we eat gets digested in our small intestine
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Why the resurgence of interest in resistant starch?
• Technological advances in the last ~5 years have shed new light on the importance of microbes in our gut
psychneuro.wordpress.com
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Do we know what makes starch resistant?
RS type 1: Entrapped starch
Edwards et al. Food & Function 2015
www.harvard-health.edu
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Do we know what makes starch resistant?
RS type 2: Native starch
Roder et al. Food Chemistry 2009
www.psu.edu
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Do we know what makes starch resistant?
RS type 3: Retrograded starch
www.food-network.com
Roder et al. Food Chemistry 2009
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Do we know what makes starch resistant?
RS type 4: Chemically modified starch
www.cbhcn.com Chen et al. RSC advances 2015
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Resistant starch as an ingredient isn’t always the best idea…
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How much resistant starch is there in my food?
• Labelling of resistant starch is a major challenge
• In the UK resistant starch isn’t included in labelling, in the US it is included as dietary fibre
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Measuring resistant starch is a major challenge
• For labelling, we need a standardised, reliable method to measure resistant starch
• Unfortunately, measuring resistant starch is a moving target
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A combination of lab based assays and ileostomy patients offers possibilities
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How can we manipulate food structure to increase resistant starch?
Edwards et al. AJCN 2015
• Exploiting natural plant food structures
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How can we manipulate food structure to increase resistant starch?
Edwards et al. AJCN 2015
• Exploiting natural plant food structures
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How can we manipulate food structure to increase resistant starch?
• Manipulating starch structure at the molecular level
www.csiro.au
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Are all resistant starches fermented in the same way in our large intestines?
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Are all resistant starches fermented in the same way in our large intestines?
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Are all resistant starches fermented in the same way in our large intestines?
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Are all resistant starches fermented in the same way in our large intestines?
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Are all resistant starches fermented in the same way in our large intestines?
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Conclusions
• Measuring, and even defining, resistant starch is a huge challenge
• Resistant starch exists in many foods, and can be increased with small tweaks to processing/ingredients
• Not all resistant starches have the same effects in our colons- and this is an area we are only just beginning to understand