30/07/2018. Defining Fibre - Challenges & Controversies. Fibre Definitions

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Tamsin York
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Defining Fibre - Challenges & Controversies Definitions vary around the world and even amongst organisations Fibre is not a single entity, not even a group of related compounds (it s a very large,

food ingredient vs when consumed within the whole grain food matrix, as synergistic activities of whole grain fibres may mediate at lest some protective effects A more detailed understanding of fibre

1 Defining Fibre - Challenges & Controversies Definitions vary around the world and even amongst organisations Fibre is not a single entity, not even a group of related compounds (it s a very large, mixed group of compounds) Different fibres have different physiological effects & health benefits The same benefits/effects may not be seen when a particular type of fibre is extracted & added as a food ingredient vs when consumed within the whole grain food matrix, as synergistic activities of whole grain fibres may mediate at lest some protective effects A more detailed understanding of fibre diversity is needed to inform our nutrition advice both to the public and to food companies, as well as to conduct and interpret nutrition research Nutrition Reviews (2007) 65:10 Food Research International (2018) 103:84 2 Fibre Definitions The term dietary fibre (DF) was first used in the 1940s & was defined simply as carbohydrate that resisted digestion and improved laxation In 1987 Englyst et al. proposed that DF be measured as non-starch polysaccharides (NSP) for the purpose of food labelling Since then, different definitions for fibre around the world has led to confusion worldwide for food labelling and for when measuring population intakes A need for a global uniform definition is clear, but not here yet, so there are some differences in fibre definitions around the world Nutrition Journal (2014) 13:34 3 1

Australian Definition Small differences exist around the world in dietary fibre definitions, but in Australia fibre is grouped into 3 main fiber type families: 1) Resistant starch; 2) Soluble fibre;

partial fermentation in the large intestine (Fig. 1); and (a) promotes one or more of the following health effects: 1) Laxation; 2) Reduction in blood cholesterol; 3) Modulation of blood glucose.

2 Australian Definition Small differences exist around the world in dietary fibre definitions, but in Australia fibre is grouped into 3 main fiber type families: 1) Resistant starch; 2) Soluble fibre; and 3) Insoluble fibre Dietary fibre means the edible part of plants or their extracts, or synthetic analogues that: (a) Resist digestion & absorption in the small intestine, usually with complete or partial fermentation in the large intestine (Fig. 1); and (a) promotes one or more of the following health effects: 1) Laxation; 2) Reduction in blood cholesterol; 3) Modulation of blood glucose. Food Standards Australia New Zealand. Standard Definitions used throughout the Code Fig: 1. Transit of fibre types during digestion 4 FDA s dietary fibre definition - for Nutrition Facts label 1. Naturally occurring fibres that are intrinsic & intact in plants, and 2. Isolated or synthetic non-digestible soluble and insoluble carbohydrates that FDA has determined have beneficial physiological effects Examples of naturally occurring fibres Naturally occurring fibre ( intrinsic ) in foods like vegetables, whole grains, fruits, cereal bran, flaked cereal and flours. Theses are considered intact as they have not been removed from the food. The 7 Isolated/synthetic fibres 1) Beta-glucan soluble fibre; 2) Psyllium husk; 3) Cellulose; 4) Guar gum; 5) Pectin; 6) Locust bean gum; 7) Hydroxypropylmethylcellulose 5 Resistant Starch The Academy of Nutrition and Dietetics defines resistant starch as a starch that escapes digestion in the small intestine and enters the colon unaltered Rapidly fermented by colonic microbiota - resulting in production of SCFA Health benefits of RS have been demonstrated extensively RS levels vary according to cooking methods, cooking & cooling, degree of ripeness e.g. cooked, then cooled potatoes are rich in RS, as the cooled starch in potatoes becomes retrograded starch and is resistant to digestion in the SI Figure: Types of starch & their absorption locations Cell Physiol Biochem 2017; 42:

Fibre Types and Food Sources The content & composition of dietary fiber varies greatly among different cereals Soluble Fibre Slows enzyme attack & carbohydrate breakdown lowers GI Reduces cholesterol

husk, Guar gum, Locust bean gum, Pectin, Hydroxypropyl methylcellulose Insoluble Fibre Bulking agent efficient laxation agent Much smaller % is fermentable Sources Barley + products Wheat bran, Brown

3 Fibre Types and Food Sources The content & composition of dietary fiber varies greatly among different cereals Soluble Fibre Slows enzyme attack & carbohydrate breakdown lowers GI Reduces cholesterol reabsorption Some have good fermentability by colonic bacteria - prebiotic Sources Barley + products Legumes Oats Barley Fruit & veg flesh Isolated/synthetic soluble fibers Beta-glucan, Psyllium husk, Guar gum, Locust bean gum, Pectin, Hydroxypropyl methylcellulose Insoluble Fibre Bulking agent efficient laxation agent Much smaller % is fermentable Sources Barley + products Wheat bran, Brown rice Wholemeal breads Whole grain cereals Flaxseed& edible seeds (in berries, tomatoes), Root vegetables (carrots, parsley, horseradish), Vegetables with edible stems (cabbage, broccoli), green beans, peas, peaches & apples Brazil nuts Isolated/synthetic insoluble fibre Cellulose Food Research International (2018) 103:84 7 Misconceptions about fibre - Not all fibres improve laxation Insoluble fibers & some soluble fibers are effective laxation promoters Insoluble fibres (e.g. wheat bran) mechanically irritate bowel, stimulating secretion of water & mucus Soluble gel-forming fibres (e.g. psyllium) have high waterholding capacity, so soften stools Some soluble fibres reduce cholesterol & improve glycaemic control (but not all) High viscosity soluble fibres (gel-forming β-glucan, psyllium, raw guar gum) do so effectively Low viscosity/nonviscous fibres (methylcellulose, inulin, wheat dextrin) do not J Acad Nutr Diet. 2017;117: J Appl Microb. 1999;86(3): PloS ONE. 2016;11(1):e FEMS Micro Ecol. 2013;83(2): PloS ONE. 2010;5(11):e Int J Food Sci Nutri. 2017;68(2): Misconceptions about Fibre - Not all fibres are prebiotic Not all fibres have prebiotic effects Resistant starch & fermentable fibres can modify gut microbiota & promote beneficial effects on large bowel function in healthy adults (e.g. SCFA) Fermentable fibres may increase bacterial mass, but do not promote regularity Fig: SCFA producing bacteria in the large bowel feed on resistant starch and fermentable fibre. Image by: Christopher Hammang (2013). 9 3

Fermentation Key for Gut Health and a Varied, Balanced Microbiota Adapted from Phys Rev. 2001;81(3):1031-64 10 The Importance of Fermentable Fibres J Nutr.

4 Fermentation Key for Gut Health and a Varied, Balanced Microbiota Adapted from Phys Rev. 2001;81(3): The Importance of Fermentable Fibres J Nutr. 2012;142:5 11 Effect of Low Fermentable Fibre Diet Decline in overall bacterial diversity Promotes growth of mucin-degrading bacteria Mucin-degrading specialists e.g. Akkermansia muciniphila Mucin-degrading generalists e.g. Bacteroides caccae Irreversible loss of some bacterial strains this gets worse over generations Decreased epithelial integrity and increased gut permeability translocation of bacterial products Specific immune pathways are affected Frontiers in Immunology 2017; 8:

Intakes of Fibre in Australia 13 NHMRC Recommendations Gender & Age Boys & girls 1-3 yr Boys & girls 4-8 yr Boys 9-13 yr Girls 9-13 yr Boys 14-18 yr Girls 14-18 yr Adult men Adult women Pregnancy 19

5 Intakes of Fibre in Australia 13 NHMRC Recommendations Gender & Age Boys & girls 1-3 yr Boys & girls 4-8 yr Boys 9-13 yr Girls 9-13 yr Boys yr Girls yr Adult men Adult women Pregnancy 19 yr+ Lactation 19 yr + Adequate Intake (AI) of fibre per day 14g 18g 24g 20g 28g 22g 30g 25g 28g 30g It s interesting to note that Palaeolithic man fibre intake was upwards of g/day, was rich in fermentable fibres and Paleo humans also consumed grains 14 Australian Fibre Intakes

6 51-70 6 70+ 4 ½ Women 19-50 6 51-70 4 70+ 3 Pregnant Lactating 9 Grain (cereal) foods, mainly

6 Where are we getting our Fibre? ABS data Aus Health Survey Australian Wholegrain Recommendations Gender & age Men ½ Women Pregnant Lactating 9 Grain (cereal) foods, mainly wholegrain* 8 ½ *Specifies at least 2/3 should be wholegrain or higher fibre In reality only 1/3 grain intake of Australians coming from wholegrains 17 Grain Fibre 18 6

Fibre from Grains Seems to be Especially Important to Health MEN WOMEN Figure: Multivariate relative risk of total and cause-specific deaths comparing the highest

05 Dietary fiber intake and mortality in the NIH-AARP Diet and Health Study, Arch Int.

7 Fibre from Grains Seems to be Especially Important to Health MEN WOMEN Figure: Multivariate relative risk of total and cause-specific deaths comparing the highest with the lowest quintile of fibre intake from food sources. CI indicates confidence interval; CVD, cardiovascular disease; and RR, relative risk. *P for trend, <0.05 Dietary fiber intake and mortality in the NIH-AARP Diet and Health Study, Arch Int. Med 2011; 171(12): Barley + Range contain a unique wholegrain BARLEYmax BARLEYmax is a superior grain developed by the CSIRO Non-GMO & superior for total fibre levels, & fibre fraction levels vs other conventionally consumed grains 20 7

valeric acids a Mean values are significantly different from Refined Wheat(P<0 05) b Mean values

8 Recognising the roles of different types of Fibre 22 Barley + Boosts Fibre, Faecal Bulk & Butyrate Production a a a, b * a *Sum of acetic, propionic, butyric, isobutyric, caproic, isovaleric and valeric acids a Mean values are significantly different from Refined Wheat(P<0 05) b Mean values are significantly different from Wholemeal wheat (P<0 05) BJN 2008; 99(5): IBS & FODMAPs 24 8

predominant) IBS-C (constipation predominant), IBS-M (mixed) No abnormal pathology 1 in 7 adults suffer from IBS 25 FODMAPs Fermentable

9 What is IBS? Chronic relapsing symptoms such as lower abdominal pain, bloating, distension, diarrhea & constipation Subtypes: IBS-D (diarrhea predominant) IBS-C (constipation predominant), IBS-M (mixed) No abnormal pathology 1 in 7 adults suffer from IBS 25 FODMAPs Fermentable Oligosaccharides, Di-saccharides, Monosaccharides And Polyols Fructans & galacto-oligosaccharides (GOS) Excess fructose Lactose Sugar polyols e.g. sorbitol & mannitol Low FODMAP effective in 7/10 IBS patients, but has potentially unfavourable effects on microbiota Not intended as diet for life concerns over self-diagnosis and application of diet without dietetic help Recommended reading: Controversies and Recent Developments of the low-fodmap Diet Gastroenterol Hepatol 2017; 13(1): FODMAPs Source: monashfodmap.com 27 9

Variations in fibre definitions has affected recommendations, labelling & research New understandings of fibre types has illuminated the

colonic health with knock-on effects on both physical & mental health Fibre supplements may have very different different effects to

10 How do FODMAPs affect those with IBS? Halmos et al (2014) Gastroenterology 146 (1): Introducing Barley + & Fermentable Fibres in FODMAP Sensitive People 29 Summary Variations in fibre definitions has affected recommendations, labelling & research New understandings of fibre types has illuminated the varying effects Fermentable fibres are key for promotion of a healthy microbiota By-products of fermentation include SCFA essential for colonic health with knock-on effects on both physical & mental health Fibre supplements may have very different different effects to consuming fibre-rich foods A variety of fibre types essential Barley + range contains unique superior grain BARLEYmax higher in all three types of fibre including resistant starch One 50g serving of Barley + Muesli provides just over 13g total fibre 30 10

References 31 References Arch Int Med 2011; 171(12):1-61. Cell Physiol Biochem 2017;42:306-318. Gibson GR, et al. Dietary prebiotics: Current status and new definition.

11 References 31 References Arch Int Med 2011; 171(12):1-61. Cell Physiol Biochem 2017;42: Gibson GR, et al. Dietary prebiotics: Current status and new definition. Food Science and Technology Bulletin: Functional Foods 2010;7 (1):1-19. Carlson J et al. Prebiotic Dietary Fiber and Gut Health: Comparing the in Vitro Fermentations of Beta-Glucan, Inulin and Xylooligosaccharide. Nutrients 2017;9:1361. Govers MJ, et al. Wheat bran affects the site of fermentation of resistant starch and luminal indexes related to colon cancer risk: a study in pigs. Gut. 1999;45(6): Brownawell et al. Prebiotics and the Health Benefits of Fiber: Current Regulatory Status, Future Research, and Goals. J. Nutr. 2012;142:5. Daïen et al. Detrimental impact of Microbiota-Accessible Carbohydrate-Deprived Diet on Gut and immune Homeostasis: An Overview. Frontiers in Immunology 2017;8:548:1-7. Murphy et al. Resistant Starch Intakes in the United States. J Am Diet Assoc. 2008;108: Clemente et al. Cell 2012;148(6): Jacobs DR, Tapsell LC. Food, not nutrients, is the fundamental unit in nutrition. Nutr Rev. 2007;65(10): Genome Med. 2016;8:77. Proc Natl Acad Sci USA 2010;107(33): Gastroenterol Hepatol 2017;13(1): BJN 2008; 99(5): Miller Jones J. Nutrition Journal 2014; 13:34 McRorie JW. & McKeown NM. Acad Nutr Diet. 2017;117: Topping DL, Clifton PM. Short-chain fatty acids and human colonic function: roles of resistant starch and nonstarch polysaccharides. Phys Rev. 2001;81(3): Nutr. Today 2015;50(2):

9/12/2017. Introduction. NHMRC Recommendations. Food Standards Australia New Zealand (FSANZ) defines Dietary Fibre as follows:

9/12/2017. Introduction. NHMRC Recommendations. Food Standards Australia New Zealand (FSANZ) defines Dietary Fibre as follows: Introduction Food Standards Australia New Zealand (FSANZ) defines Dietary Fibre as follows: Dietary fibre means that fraction of the edible parts of plants or their extracts, or synthetic analogues, that