Latest Insight Into the Effect of Food and Diet on the Gut Microbiome

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1 Latest Insight Into the Effect of Food and Diet on the Gut Microbiome Professor Bob Rastall Department of Food and Nutritional Sciences The University of Reading

2 The gut microbiome Oligosaccharides Polysaccharides Mucins Proteins & peptides Bifidobacterium Lactobacillus Bacteroides Clostridium IV F. prausnitzii Succinate Clostridium IX SO 4 -- clostridia peptostreptococci peptococci CO 2 Lactate Clostridium XIVa E. halli R. hominis Sulfate Reducing Bacteria H 2 S Acetogens H 2 Methanogens Methane Acetate Butyrate Propionate Modified from Sarbini and Rastall (2011) Funct. Food Rev. 3: Isovalerate Isobutyrate 2-methylbutyrate p-cresyl sulphate Indoxyl sulphate NH 4 + Amines Phenol Skatole Indole

3 Carbohydrates have a selective impact on the gut microbiome

4 Fermentation and the gut microbiome Oligosaccharides Polysaccharides Mucins Proteins & peptides Bifidobacterium Lactobacillus Bacteroides Clostridium IV F. prausnitzii Succinate Clostridium IX SO 4 -- clostridia peptostreptococci peptococci CO 2 Lactate Clostridium XIVa E. halli R. hominis Sulfate Reducing Bacteria H 2 S Acetogens H 2 Methanogens Methane Acetate Butyrate Propionate Modified from Sarbini and Rastall (2011) Funct. Food Rev. 3: Isovalerate Isobutyrate 2-methylbutyrate p-cresyl sulphate Indoxyl sulphate NH 4 + Amines Phenol Skatole Indole

5 Polysaccharide metabolism Fructan polysaccharide utilisation locus in Bacteroides thetaiotaomicron b-fructofuranosidase b-2,6-fructanase Frub2 [6Frub2 ]6Frub2 1aGlc Fructokinase b-fructosidase b-2,6-fructanase b-fructosidase Hybrid two-component system Senses fructose and upregulates the PUL Cytoplasmic membrane monosaccharide transport Outer membrane polysaccharide binding and transport Sonnenburg et al (2010), Cell 141;

6 Fermentation and the gut microbiome Oligosaccharides Polysaccharides Mucins Proteins & peptides Bifidobacterium Lactobacillus Bacteroides Clostridium IV F. prausnitzii Succinate Clostridium IX SO 4 -- clostridia peptostreptococci peptococci CO 2 Lactate Clostridium XIVa E. halli R. hominis Sulfate Reducing Bacteria H 2 S Acetogens H 2 Methanogens Methane Acetate Butyrate Propionate Modified from Sarbini and Rastall (2011) Funct. Food Rev. 3: Isovalerate Isobutyrate 2-methylbutyrate p-cresyl sulphate Indoxyl sulphate NH 4 + Amines Phenol Skatole Indole

7 Cross-feeding in the gut Bacteroides thetaiotaomicron Anaerostipes caccae Bifidobacterium adolescentis Bifidobacterium longum Bifidobacterium angulatum Roseburia hominis Roseburia intestinalis Lactate Acetate Butyrate Eubacterium hallii

8 OTU 1111 OTU 1144 Sutterella Gemmiger Parasutterella OTU 4114 Collinsella Bifidobacterium Barnesiella Prevotella Xylanibacter Allistipes OTU2145 OTU 2171 Bacteroides Parabacteroides Allisonella Butyricicoccus Clostridium XI Anaerovorax Anaerococcus Clostridium Streptococcus Lactococcus Lactobacillus Dialister Lachnospiraceae Oscillibacter OTU 2832 Subdoligranulum Ruminococcus OTU 2620 Dorea Faecalibacterium Clostridium XIVa OTU 1291 OTU 2128 Erysipelotrichaceae Roseburia Coprococcus Acetovibrio Blautia OTU 5111 Clostridium XIVb Clostridium IV Enterococcus Anaerostipes Catenibacterium Selective metabolism of carbohydrates TIM-2 Lactulose GOS Sugar beet fibre Apple fibre Aguirre et al (2014), PLOS One, DOI: /journal.pone Log relative change after 72h

9 Metabolism of carbohydrates FOS XOS Acetate Butyrate Propionate Cellobiose Resistant starch Pectin b-glucan Polygalacturonic acid Galactan Arabinan Rhamnogalacturonan

10 Prebiotics A dietary prebiotic is a selectively fermented Easy to measure More challenging ingredient that results in specific changes, in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health Gibson, G. R., Scott, K. P., Rastall, R. A., Tuohy, K. M., Hotchkiss, A., Dubert-Ferrandon, A., Gareau, M., Murphy, E. F., Saulnier, D., Loh, G., Macfarlane, S., Delzenne, N., Ringel, Y., Kozianowski, G., Dickmann, Very challenging R., Lenoir-Wijnkook, to I., establish Walker, C. and in Buddington, humans R. International Scientific Association for Probiotics and Prebiotics, Nov 2008, London, Ontario IFIS Functional Foods Bulletin 2011; 7, 1 19

11 Reported prebiotic oligosaccharides Inulin Fructo-oligosaccharides Galacto-oligosaccharides Xylo-oligosaccharides Isomalto-oligosaccharides Lactulose Lactosucrose Resistant starches Soybean oligosaccharides Gentio-oligosaccharides Group A Good microbiology with state of the art techniques Good human studies Health benefits shown Group B Some good microbiology with state of the art techniques Some or poor human studies Few health benefits shown Group C Little or poor microbiology often with questionable techniques No human studies No health benefits shown

12 Th1 Tr improved bowel habit Prebiotics immunomodulation IFNg IL-10 TGF-b adhesion inhibition Th2 allergy prevention selective fermentation faecal bulking reduced inflammation IL-10 IL-1b IL-6 regulation of peristalsis? GPR41 GPR43 impact on chronic kidney disease? reduced renal toxicity Butyrate p-cresyl sulphate indoxyl sulphate Acetate increased absorption Ca ++ reduced ph Propionate reduced tumour promoters reduced infection NK activity M Cell defence against pathogens GPR41 GPR43 phagocytic activity immune stimulation reduced infection reduced intestinal infection maintenance of barrier function Zonulin Occludin GLP-2 ZO1 Reduced cancer risk? GLP-1 PYY Ghrelin reduced inflammation Mood? reduced LPS translocation insulin sensitivity increased satiety

13 Dietary carbohydrates can prevent bacteria from adhering to cells at least in vitro

14 Adhesion relative to control (%) Invasion relative to control (%) Antiadhesive pectins Adhesion to HT29 cells 100 Invasion of CACO-2 cells by C. jejuni * * * * * * * * POS conc. (mg/ml) Rhoades et al (2008) Journal of Food Protection 71: Ganan et al (2010) International Journal of Food Microbiology 137:

15 Inhibition (% of control) Inhibition (% of control) Antiadhesive prebiotics Adhesion of Listeria monocytogenes to Caco-2 cells Enteropathogenic E. coli E2348/69 Attachment to HEp-2 cells * Inulin XOS GOS * * ScottA [GOS] (mg / ml) Ebersbach et al. (2012) Res. Micro. 163: Shoaf et al. (2006) Infection and Immunity 74:

16 Are metabolites of protein fermentation really that harmful?

17 Proteins and the gut microbiome Oligosaccharides Polysaccharides Mucins Proteins & peptides Bifidobacterium Lactobacillus Bacteroides Clostridium IV F. prausnitzii Succinate Clostridium IX SO 4 -- clostridia peptostreptococci peptococci CO 2 Lactate Clostridium XIVa E. halli R. hominis Sulfate Reducing Bacteria H 2 S Acetogens H 2 Methanogens Methane Acetate Butyrate Propionate Modified from Sarbini and Rastall (2011) Funct. Food Rev. 3: Isovalerate Isobutyrate 2-methylbutyrate p-cresyl sulphate Indoxyl sulphate NH 4 + Amines Phenol Skatole Indole

18 Proteins and the gut microbiome Co-carcinogen promotes formation of nitroso compounds Phenol Indole p-cresol Phase II metabolism Cellular toxicity Reduction in endothelial proliferation Genotoxic Reduction in barrier function H 2 S Indoxylsulfate p-cresylsulfate NH 4 + Genotoxic Mucosal inflammation Uraemic toxins Disrupts energy metabolism in colonocytes Portune et al (2016), Trends Food. Sci. Techol. Verbeke et al (2015), Nutr. Res. Rev., 28: Nyangale et al (2012), J. Proteome Res, 11:

19 Proteins and the gut microbiome p-cresol Phenol NOAEL 230mg/kg/d (JECFA) TDI 37.5mg/75kg/d (EFSA) Urinary excretion mg/d 0 Faecal concentration mg/g 4 Urinary excretion mg/d 0 Faecal concentration mg/g Verbeke et al (2015), Nutr. Res. Rev., 28: 42-66

20 Dietary polyphenols can modulate the gut microbiome

21 Polyphenols in the diet Estimated that 90-95% enter the colon Berries: (Anthocyanins) Citrus: (Flavanone) Cocoa: (Flavanols and procyanidins) Red wine: (Flavanol, Flavonols) Fruit and vegetables: (All classes) Tea: (Flavanols)

22 Log 10 copies per gram faeces Polyphenols and the gut microbiome 10 volunteers on a randomised crossover trial Bacteriology by qpcr 10 Baseline 9 Alcohol free red wine 8 Red wine Gin Queipo-Ortuno et al (2012), Am. J. Clin. Nutr., 95:

23 Polyphenols and the gut microbiome Bifidobacterium Collinsella Bacteroides Parabacteroides Prevotella Butyricimonas Odoribacter Enterococcus Lactobacillus Streptococcus Unknown clostridiaceae Clostridium Unknown clostridiaceae Blautia Coprococcus Ruminococcus Unknown peptostreptococcaceae Unknown peptostreptococcaceae Faecalibacterium Oscillospira Ruminococcus Megasphaera Phascolarctobacterium Unknown erysipelotrichaceae Eubacterium Fusobacterium Ochrobactrum Sutterella Unknown alcaligenaceae Klebsiella Halomonas Content relative to total bacteria (%) Control Quercetin Huang et al (2016), J. Food Sci, 81: H2273-H2279

24 Polyphenols and the gut microbiome Bifidobacterium Collinsella Bacteroides Parabacteroides Prevotella Butyricimonas Odoribacter Enterococcus Lactobacillus Streptococcus Unknown clostridiaceae Clostridium Unknown clostridiaceae Blautia Coprococcus Ruminococcus Unknown peptostreptococcaceae Unknown peptostreptococcaceae Faecalibacterium Oscillospira Ruminococcus Megasphaera Phascolarctobacterium Unknown erysipelotrichaceae Eubacterium Fusobacterium Ochrobactrum Sutterella Unknown alcaligenaceae Klebsiella Halomonas Content relative to total bacteria (%) Control Catechin Huang et al (2016), J. Food Sci, 81: H2273-H2279

25 Polyphenols and the gut microbiome Bifidobacterium Collinsella Bacteroides Parabacteroides Prevotella Butyricimonas Odoribacter Enterococcus Lactobacillus Streptococcus Unknown clostridiaceae Clostridium Unknown clostridiaceae Blautia Coprococcus Ruminococcus Unknown peptostreptococcaceae Unknown peptostreptococcaceae Faecalibacterium Oscillospira Ruminococcus Megasphaera Phascolarctobacterium Unknown erysipelotrichaceae Eubacterium Fusobacterium Ochrobactrum Sutterella Unknown alcaligenaceae Klebsiella Halomonas P<0.05 P<0.05 Content relative to total bacteria (%) Control Puerarin Huang et al (2016), J. Food Sci, 81: H2273-H2279

26 Vitamins may also impact on the gut microbiome

27 Vitamin B2 and F. prausnitzii Faecalibacterium prausnitzii is a strict anaerobe Riboflavin (vitamin B2) can act as a redox mediator in the gut Oxygen Riboflavin NAD + H 2 O Riboflavin NADH Energy metabolism Reduces oxygen stress and allows a higher population to grow F. prausnitzii cell Steinert et al (2016), Europ. J. Clin. Nutr. doi: /ejcn

28 E. coli per gram faeces (x 10 8 ) F. prausnitzii per gram faeces (x 10 9 ) Vitamin B2 and F. prausnitzii Up to 30mg absorbed in the small intestine 11 volunteers fed 100mg riboflavin per day for 2 weeks 3 E. coli before E. coli after F. prausnitzii before F. prausnitzii after Steinert et al (2016), Europ. J. Clin. Nutr. doi: /ejcn

29 Can we define a healthy gut microbiome?

30 What is a healthy gut microbiome? Vitamin levels: B12 K Cytokines from PBMC: IL-10 IL-8 IL-6 IL-1b IFNg Antimicrobial activity: E. coli pathovars Salmonella Typhimurium Campylobacter jejuni Products of saccharolytic metabolism: Acetate Lactate Succinate Butyrate Propionate Intestinal barrier function: TEER assay Gas formation: Rate H 2 CO 2 CH 4 LPS levels: LAL assay Genotoxic activity: Comet assay Products of proteolytic metabolism: Phenol Indole Skatole Ammonia Branched chain fatty acids Toxic products of metabolism: H 2 S Known bacterial toxins: Shiga toxin C. difficile toxins C. perfringens toxins Biotransforming enzymes: b-glucosidase b-glucuronidase Azoreductase

31 What is a healthy gut microbiome? Composition Bifidobacterium Lactobacillus Faecalibacterium prausnitzii Clostridium perfringens C. difficile Sulfate reducing bacteria Products Acetate Butyrate Propionate Phenols NH 4 + Amines H 2 S Toxins Properties Hostile environment to transient pathogens Low genotoxicity

32 Concluding thoughts We are learning more about the impact of dietary components on the diet Causative relationships to health still elusive We need a much better knowledge of metabolites in the gut Definition of prebiotic coming under debate A mechanism? An effect? We cannot precisely define a healthy gut microbiome

33 Thank you for your attention Professor Bob Rastall will be on the University of Reading stand RP13: Wednesday 2-5 Thursday 10-4