What really is a prebiotic and why? ISAPP Cork 2012 Discussion Group 1

Transcription

1 What really is a prebiotic and why? ISAPP Cork 2012 Discussion Group 1

2 Juliet Ansell Paul Blatchford George Fahey Glenn Gibson Yong Jun Goh Arland Hotchkiss Bob Hutkins Christophe Lacroix Jose Garcia Mazcorro Bob Rastall Raylene Reimer Margriet Schoterman Douwe Van Sinderen Koen Venema Kevin Whelan

3 Which of the following is not a good idea for a first time visitor to Ireland? Look to the left before crossing a busy street Beer-drinking contest with an Irishman Leave the presentation preparation up to Gibson and Rastall (in the pub)

4 Definition history Discussion themes Does structure determine function? Evaluating prebiotics Bioactivites of prebiotics, including extraintestinal (and extrahuman) effects Concluding thoughts: What makes a prebiotic a prebiotic

5 The original prebiotic concept from 1995 to ISAPP ISAPP Cork Discussion Group 1

6 Prebiotic definition A non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health Gibson, G. R., Roberfroid, M. B. J. Nutr. 125, , 1995 A prebiotic is a non-viable food component that confers a health benefit on the host associated with modulation of the microbiota Maya Pineiro, Nils-Georg Asp, Oscar Brunser, Sandra Macfarlane, Lorenzo Morelli, Gregor Reid and Kieran Tuohy. FAO Technical Report November 2007, Rome A dietary prebiotic is a selectively fermented ingredient that results in specific changes, in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health ISAPP definition, IFIS Functional Foods Bulletin, 2010 A prebiotic is a non-viable food component, ingredient or supplement that selectively modulates the microbiota of the digestive ecosystems, thus conferring benefits upon host wellbeing and health Marcel Roberfroid, Francisco Guarner, Sandra Macfarlane, Satoshi Kudo, Bernd Stahl and Bob Rastall. ILSI Expert Group on the Working Definition of Prebiotics, 17th April 2008, Brussels

7 The EFSA NDA panel holding an expert consultation...

8 Does structure affect function? ISAPP Cork Discussion Group 1

9 Pectin a polysaccharide with multiple functional groups RG I XGA HGA RG II Galactose Glucuronic acid Apiose KDO Arabinose Galcturonic acid Fucose Aceric acid Rhamnose Acetyl- methyl- Xylose DHA

10 Log 10 cells/g Bifidogenic effects of pectic oligosaccharides FOS POS Batch culture, 1% CHO, ph 6.8, bacteriology by FISH Manderson et al (2005), Applied and Environmental Microbiology 71;

11 Prebiotic potential RG I XGA HGA RG II Galactose Glucuronic acid Apiose KDO Arabinose Galcturonic acid Fucose Aceric acid Rhamnose Acetyl- methyl- Xylose DHA

12 Evaluation of prebiotics ISAPP Cork Discussion Group 1

13 Human gut - systems biology analyses Pro- and Prebiotics Impact Gut Functions & Health Molecular and mechanistic studies In vitro gut fermentation models In vitro human intestinal cell models In vivo animal studies In vivo human studies Systems biology tools Metagenomics Transcriptomics Proteomics Metabolomics Payne et al 2012 Trends Biotechnol 30:17 Freitag, 5. Oktober C. Lacroix - LFB - ETH Zurich

14 Prebiotic effects and the gut: testing

15 delta plasma glucose First experiments in humans with 13 C-lactose!! delta breath CO 2 breath hydrogen (ppm) C-CO 2 H 2 13 C-glucose individual no 13 C-glucose in plasma - increase in 13 C-CO 2 in breath - increase in 13 C-acetate in plasma - increase in breath H 2 fermentation of 13 C-lactose in colon

16 In vitro models of digestive ecosystems: Perspectives and future directions? Reliable-efficient to study mechanistic effects, e.g. cross feedings Use of in vitro models with omics techniques New models: miniaturisation, automation and high throughput Combine in vitro fermentation models and cell models to add host-microbe interactions Need to avoid studying models for the sake of the models

17 Assessing prebiotic actitivity by functional genome analysis Palatinose Stachyose/Raffinose/Melibiose Melezitose Fucose Kojibiose Lacto-N-biose Lactose/Lactulose Ribose Cellodextrin Starch/Glycogen/ Amylopectin/Pullulan Sialic Acid Fructose Fructo-oligosaccharides/ Sucrose Galactan/ Galacto-oligosaccharides N-linked Glycans Palatinose UCC2003 is specialised to metabolise host & plant-derived glycans

18 Functional genome analysis Comparison of gene clusters to show transporters, regulators, permeases, hydrolases, etc. For example LacS in most GI lactobacilli GOS gene cluster upregulated by bile Confirmed uptake of trisaccharides by bifidobacteria Demonstration of diversity of prebiotic utilising pathways in lactobacilli

19 Diversity of FOS utilisation pathways in lactobacilli cell wall-anchored BfrA Cell wall-anchored BfrA/Fructose-PTS L. paracasei (Goh et al., 2006) ABC transporter L. acidophilus P (Barrangou et al., 2003) Intracellular BfrA Sucrose-PTS L. plantarum (Saulnier et al., 2007) P Oligosaccharide/H + symporter L. ruminus (O Donnell et al., 2011) Pathogenic E. coli (Schouler et al., 2009) fructose glucose

20 Metabolic diversity of oligosaccharides utilization by L. acidophilus PTS Gentiobiose ( -1,6) Cellobiose -glucan oligomers ( -1,4) Isomaltose Isomaltulose Panose Polydextrose Phospho- glucosidase I Phospho- glucosidase II Maltose 6-P glucosidase ABC Maltose phosphorylase Polydextrose FOS Raffinose Stachyose -Galactosidase Sucrose phosphorylase -Galactosidase MFS GOS Lactitol Lactulose? -Glu -Glu -Gal -Gal Andersen et al., PLOS ONE 2012

21 Evaluating prebiotics from the consumer perspective Q1: should the definition of a prebiotic relate to the treatment of disease as well as the maintenance or improvement of health? Q2: thinking of the definition(s) of prebiotic can we call a compound prebiotic if it does not change the numbers of microbiota nor treat disease? Q3: should the term prebiotic relate to a specific compound in a specific product in a specific dose in a specific disease (Sanders)? Q4: are patients able to access prebiotics? Q5: how can patients access reliable information on prebiotics?

22 Do people use probiotics and prebiotics? Have you ever used... for your health Crohn s (n=131) UC (n=103) Controls (n=100) P value Probiotics 43% 51% 21% <0.001 Prebiotics Hedin et al, Inflamm Bowel Dis 2010; 16:

23 Do people use probiotics and prebiotics? Have you ever used... for your health Crohn s (n=131) UC (n=103) Controls (n=100) P value Probiotics 43% 51% 21% <0.001 Prebiotics 4% 2% 1% Hedin et al, Inflamm Bowel Dis 2010; 16:

24 People don t know much about prebiotics What is a Crohn s (n=131) UC (n=103) Controls (n=100) P value Probiotic, mean score ) bacteria, bug, microbe etc 41% 52% 26% ) health benefit, treat disease 28% 41% 31% ) name of a strain or product 27% 30% 15% Prebiotics, mean score ) food substance, fibre, etc 3% 1% 0% - 2) increase bacteria, increase activity 2% 1% 1% - 3) health benefit, treat disease 1% 0% 0% - Q5: how can patients access reliable information on prebiotics? Hedin et al, Inflamm Bowel Dis 2010; 16:

25 Bioactivities of prebiotics ISAPP Cork Discussion Group 1

26 Extraintestinal effects Atopic diseases Respiratory infections Vaginal effects Oral disease Liver disease Skin effects Adiposity Most implicate gut microbiota modulation as an explanation of effect

27 Prebiotics reduce adiposity G-protein coupled receptor 43 (GPR43) reduces lipolysis and stimulates lipogenesis ---- prebiotics reduce GPR43 Adipocyte fatty acid binding protein (ap2) promotes adipocyte differentiation. Fat mass increases by increasing size and the formation of new adipocytes from precursor cells ---- prebiotics reduce differentiation Lipoprotein lipase (LPL) promotes fat storage in adipose tissue prebiotics reduce LPL

28 Prebiotics and the canine: meta-analysis 15 published studies ( ) 65 dietary treatments 418 observations Evaluated the effects of prebiotics on: Nutrient digestibility SCFA concentrations Bacterial populations Serum immunoglobulin concentrations Patra, 2011 Beynen et al. (2002) Diez et al. (1998) Flickinger et al. (2003) Flickinger et al. (2003) Grieshop et al. (2002) Grieshop et al. (2004) Hesta et al. (2003) Middelbos et al. (2007a) Middelbos et al. (2007b) Propst et al. (2003) Strickling et al. (2000) Swanson et al. (2002a) Swanson et al. (2002b) Swanson et al. (2002c) Verlinden et al. (2006) Zentek et al. (2002)

29 Future of prebiotics for companion animals Compositional analysis of potential prebiotics Monomeric composition Chain length Linkages Branching Side chains Prebiotic activity of natural foods Soybean products Beet fibre Whole grains and co-products

30 Future of prebiotics for companion animals Microbiota beyond bifidobacteria Detailed composition 16S rdna pyrosequencing Metabolic function metagenomics approach Need to study microbiomeindices of health relationships How do prebiotics achieve benefits for disease?

31 Prebiotic oligosaccharides: beyond bifidogenicity Saulnier et al;., 2009

32 Adhesins, Ligands, and Sticktoitiveness

33 Prebiotics as anti-adhesive agents

34

35

36 Adhesion relative to control (%) Antiadhesive pectic oligosaccharides * * * * * * * * Rhoades et al (2008) Journal of Food Protection 71:

37 Bioactivity in pectins RG I XGA HGA RG II Galactose Glucuronic acid Apiose KDO Arabinose Galcturonic acid Fucose Aceric acid Rhamnose Acetyl- methyl- Xylose DHA

38 Exploiting anti-adhesive prebiotics 1. Increase the avidity of adhesin for ligand Increase ligand affinity Increase ligand valency 2. Mixtures of anti-adhesins to counter phase variation 3. Isolation of anti-adhesin agents from natural sources 4. Prevention of extra-intestinal infections 5. Synthesis of natural/novel anti-adhesin agents 2-fucosyllactose Lee et al Microbial Cell Factories

39 Percentage sequence abundance Prebiotic activity in whole foods: kiwifruit as an example h 24h 48h Donor 1 0h 24h 48h Donor 2 0h 24h 48h Donor 3 Rhodospirillaceae Enterobacteriaceae Alcaligenaceae Bifidobacteriaceae Coriobacteriaceae Veillonellaceae Lachnospiraceae Bacillaceae Streptococcaceae Ruminococcaceae Rikenellaceae Porphyromonadaceae Bacteroidaceae Prevotellaceae Bacteroidetes Firmicutes Actinobacteria Proteobacteria

40 A simplified view of prebiotics and the functional network in the gut Formate Pentoses Arabinose Xylose Ribose Pentose phosphate pathway Roseburia/Eubacterium group Faecalibacterium prausnitzii Lachnospira/Ruminococcus spp. Actinobacteria Proteobacteria Hexoses Galactose Mannose Glucose Glycolytic Pathway Phosphoenolpyruvate all Pyruvate Deoxy hexoses Fucose Rhamnose Roseburia inulinivorans Bacteroidetes Proteobacteria DHAP + lactaldehyde Bacteroidetes Proteobacteria Roseburia inulinivorans Pseudobutyrivibrio Bacteroidetes Proteobacteria Pseudobutyrivibrio Roseburia inulinivorans Bacteroidetes Proteobacteria LEGEND Intermediate metabolite (not measured) Propionate pathway intermediate metabolite (not measured) Propionate pathway intermediate metabolite (measured) Other excreted end point metabolites Measured intermediate SCFA Measured end-point SCFA Bacteria CH 4, CO 2, H + Roseburia/Eubacterium group Faecalibacterium prausnitzii Lachnospira/Ruminococcus spp. Lactobacillus/Enterococcus spp. Actinobacteria Proteobacteria all Acetyl-CoA Oxaloacetate Bacteroidetes Proteobacteria Ruminococcus spp. Propane-1,2-diol Propane-1,2-diol Roseburia/Eubacterium group Faecalibacterium prausnitzii Roseburia/Eubacterium group Faecalibacterium prausnitzii Roseburia inulinivorans Lactate Butyrate Actinobacteria Lachnospira/Ruminococcus spp. Lactobacillus/Enterococcus spp. Veillonellaceae Actinobacteria Bacteroidetes Proteobacteria Succinate Bacteroidetes Propionate Veillonellaceae CH 4, CO 2 Acetate Veillonellaceae Adapted from: Louis et al. (2007) J. Appl. Micro. 102, ; Macfarlane & Marfarlane (2003) Proc. Nutr. Soc. 62, W. J. Kelly (AgResearch, NZ, pers. comm., 2012) Acrylyl-CoA

41 Conclusions: What makes a prebiotic a prebiotic (and how do you know)? ISAPP Cork Discussion Group 1

42 What should we be measuring? Who is there? Integrated approach to microbiota characterization Genomic sequencing, metagenomics, FISH, qpcr, DGGE, etc. Need to test with the best technology available What are they doing? In vitro SCFA and other organic acids Biotransforming enzyme activities Urinary, blood, faecal metabolites Immunology Blood lipids Patient symptoms No gas no glory...

43 What really is a prebiotic and why? Now: FOS and GOS - structure, size, host enzymology Focus on "probiotics" - bifidobacteria and lactobacilli Simple view of metabolism - SCFA In the future: Model systems will become more sophisticated New target microorganisms - will need new prebiotics Multiple functionality Understanding carbon flux through the microbiome, its impact on microbial activity and consequent impact on health