Exploring the link between gut microbiota and metabolic health

Ellen Blaak

Professor in Physiology of fat metabolism, Department of Human Biology NUTRIM School of Nutrition and Translational Research in Metabolism

Maastricht University Medical Centre+

The Netherlands

Food Matters Live, Nov 21-23rd, London

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Overview

• Modulation of microbiota and metabolic health:

• feces transplantation and antibiotics

• Role of SCFA and metabolic health:

• Colonic SCFA administration

• Intervention with prebiotics-dietary fibers

of Human Biology

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Microbiota, obesity and type 2 diabetes mellitus

• Worldwide, obesity is reaching epidemic proportions

• The obesity pandemic is not fully explained by most common gene-environment interactions

• Gut microbiota provide additional gene products that may affect host metabolism, gut physiology, body weight control and insulin sensitivity through several mechanisms

• Obesity and Type 2 diabetes mellitus are associated with differential composition of gut microbiota and/or gut microbiome

• Interventions to manipulate gut-microbiota may favorably affect metabolism and reduce diabesity risk

of Human Biology

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Obesity – pandemic of 21st century

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Cardiovascular disease Type 2 diabetes Liver steatosis Cancer

OBESITY

of Human Biology

Obesity: an important risk factor for chronic metabolic diseases

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Feces transplantation from mice to mice

of Human Biology

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From mice to mice: Gut Flora contributes to the high-fat induced metabolic diseases in mice

(Bäckhed et al, 2004, 2007)

Germ-free mice are protected from development of

insulin resistance and glucose intolerance of Human Biology

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From man to mice: Gut microbiota from twins discordant

for obesity modulate metabolism in mice

of Human Biology

V K Ridaura et al. Science 2013;341:1241214

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From man to man: feces transplantation and human

metabolism

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Transferring microbiota between conventional and germ free rodents, humans and rodents and humans and humans have shown the role of intestinal microbiota in the development of obesity and insulin resistance

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Department of Human Biology

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Antibiotics intervention

40-70y

IFG/IGT

HOMA-IR>2.2

n=56

wk 1 pre

wk 2

2d wash out

wk 3 post

wk 8 follow-

up

Treatment Timing

Placebo

Amoxicillin

Vancomycin

1500 mg/day

7 days

of Human Biology Reijnders et al, Cell metabolism, 2016

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Microbiota composition

• Vanco:

– Increased gram

negative

Proteobacteria

– less gram-

positive bacteria

– decreased

diversity

– After 8 weeks

similarity with

baseline still

lower, diversity

slightly lower

• Amox:

• no diversity

and/or

composition

differences

Distinct changes in microbiota composition

of Human Biology Reijnders et al, Cell metabolism, 2016

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No effect on insulin sensitivity

Two-step hyperinsulinemic-euglycemic clamp

Endogenous Glucose Production

Rate of Disappearance

Suppression of Free Fatty Acids

%

of Human Biology Reijnders et al, Cell metabolism, 2016

No effect on whole body insulin resistance 8 wk after stopping the active intervention

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of Human Biology Reijnders et al, Cell metabolism, 2016

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Perspectives

• Modulation of adult microbiota by 7-day antibiotics does not affect host metabolism

• Host metabolism remained unchanged at 8-week

follow-up, despite deviant microbiota

• Contradicts many rodents studies!

• More frequent antibiotic use, long term diet effects?

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Function of micrbiota: site of fermentation

proximal colon: primarily saccharolytic

fermentation

transverse colon: combination of saccharolytic and proteolytic fermentation

distal colon: primarily proteolytic fermentation

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Acetate

Propionate

Butyrate

Major SCFA

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Canfora, E. E. et al. (2015) Short-chain fatty acids in control of body weight and insulin sensitivity

Nature Reviews Endocrinology doi:10.1038/nrendo.2015.128

Functionality of microbiota: SCFA

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Colonic acetate infusion and metabolic profile

Hypothesis:Colonic administration of SCFA has beneficial

effects on human substrate and energy metabolism

Question:

Where to administer? Distal / Proximal?

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Distal and proximal colonic acetate infusion and metabolic profile

Aim:

To investigate differential effects of proximal and distal colonic infusions with sodium

acetate on human fat oxidation, energy expenditure and circulating metabolic

markers

Study design

• Double blind, placebo controlled, randomized crossover study

• Six healthy overweight males (BMI 25 – 34.9 kg/m2)

Aged 20 – 50 years;

Weight stable for at least 3 months (± 2 kg)

No use of antibiotics, pre- or probiotics

Intervention

1. Sodium acetate 100mmol/L (12mmol in 120mL water)

2. Sodium acetate 180mmol/L (21.6mmol in 120mL water)

3. Placebo (0.9% NaCl) in 120mL

of Human Biology Van der Beek et al, Clin Sci 2017

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Intervention protocol

of Human Biology Van der Beek et al, Clin Sci 2017

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Figure 3. Test day

!

Test day protocol

of Human Biology Van der Beek et al, Clin Sci 2017

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Fat oxidation

ANOVA * p<0.05 placebo vs 180mM Ingestion oral glucose solution

break

break

Placebo 100 mmol/L 180 mmol/L-2

-1

0

1

2

3

Fa

t oxid

atio

n (g

fa

t 2h

-1) *

p=0.055

iAUC, distal

placebo

100mmol/L

180mmol/L

of Human Biology Van der Beek et al, Clin Sci 2017

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Increasing colonic and systemic acetate beneficially affect the

metabolic profile

Validated distal colonic infusion as a good model to study SCFA

effects on metabolism

Circulating acetate

Fat oxidation

PYY

TNF-α

Lipolysis

No significant effects

of Human Biology Van der Beek et al, Clin Sci 2017

Distal, not proximal, colonic acetate infusion improves metabolic profile

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Combinations of SCFA and metabolic profile

To investigate acute effects of distal colonic infusions of

SCFA combinations on substrate and energy

metabolism

of Human Biology Canfora et al, Scientific reports, 2017

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Intervention protocol (1)

Double blind, placebo controlled, randomized crossover study with 4 distal

infusions:

• Placebo:

40mmol NaCl

• High sodium acetate (60:20:20):

24mmol NaAc, 8mmol NaBu, 8mmol NaPr

• High sodium butyrate (45:35:20):

18mmol NaAc , 14mmol NaBu, 8mmol NaPr

• High sodium propionate (45:20:35):

18mmol Na Ac, 8mmol NaBu, 14mmol NaPr

• All diluted in 200mL water

0

20

40

60

80

100

60:20:20 45:35:20 45:35:20 Placebo

sodiumchloride

sodiumpropionate

sodiumbutyrate

sodiumacetate%

SCFA/N

aCl in

solu

tions

45:20:35

of Human Biology Canfora et al, Scientific reports, 2017

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SCFA increase Fat oxidation

*** p<0.001, ** p<0.01 Ingestion oral glucose

***

of Human Biology Canfora et al, Scientific reports, 2017

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SCFA increase Energy Expenditure

*** p<0.001, * p<0.05, # p<0.1 Ingestion oral glucose solution

*

plac

ebo

high

ace

tate

high

pro

pion

ate

high

but

yrat

e

0

20

40

iAUC energy expenditure, fasted

****

#

iAU

C E

E k

J/t0

-t1

20

of Human Biology Canfora et al, Scientific reports, 2017

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Fat oxidation

Energy Expenditure

PYY

IL-1β ↓

lipolysis ↓

Acetate maybe a target to prevent and treat obesity-

related co-morbidities

of Human Biology Canfora et al, Scientific reports, 2017

What are the underlying mechanisms?

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Why do we hypothesize that the distal colon should be targeted?

Kuwahara (2014), Frontiers in Endocrinology

Higher density of PYY-producing L-cells in the distal colon

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Increased fat oxidation and EE only after distal administration: Acetate bypass the liver circulating acetate uptake in oxidative

tissues pAMPK fat oxidation

Circulating

Acetate

Acetate pAMPK fat

oxidation1,2,3

1Sakakibara et al., 2006; 2Yamashita et al., 2009; 3Kimura et al., 2013; 4 den Besten et al., 2015

Acetate pAMPK fat

oxidation1,2,4

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Fermentation of fibers by the gut microbiota –

proximal versus distal

Which fibers are best?

Canfora, et al. (2017), Scientific Reports;7(1):2360

fermented distally

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In Summary

• Feces transplantation studies do show a role of microbiota in weight

gain and insulin resistance, effects in humans are relatively minor

• Modulation of microbiota by means of antibiotics did not affect

metabolic health after 7 days and in the longer term

• SCFA may be an important link between gut microbiota and metabolic

health

• Distal, but not proximal, acetate infusion may improve fat oxidation

and metabolic profile

• Rectal infusion of SCFA combinations all increase fat oxidation,

energy expenditure and metabolic profile

• Dietary fiber intervention focussed on targeted production of SCFA

may improve intervention outcome with respect to metabolic profile,

but this requires further confirmation

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Collaborations/Acknowledgements

• Gijs Goossens

• Johan Jocken

• Birgitta van der Kolk

• Dorien Reijnders

• Emanuel Canfora

• Rudi Stinkens

• Max Vogel

• Jasper Most

• Mattea Müller

• Kenneth Verboven

• Yvonne Essers

• Nicole Hoebers

Dept Human Biology, MUMC

And external

Collaborations

Top Institute Food and Nutrition

(project GH003, microbiota, energy balance

and metabolism)

EU consortia: EU-Lipgene, MIRdiet, EDIPS, Diogenes

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Future Directions…..