Joslin Diabetes CenterPrimary Care Congress for Cardiometabolic Health 2013The GI Tract in the Etiology of the Cardiometabolic Syndrome

Copyright © 2013 by Joslin Diabetes Center, Inc. All rights reserved. These materials may be used for personal use only. Any distribution or reuse of this presentation or any part of it in any form for other than personal use without the express written permission of Joslin Diabetes Center is prohibited.

The microbiome: A historical perspective

> 1985‐1991 Norman Pace pioneered use of PCR to explore diversity of rRNA seq’s.  First report of bulk isolation and cloning of DNA from environmental samples.

> 1991 David Relman uses new sequencing methods to discover bacterial causes of many diseases (cat scratch fever, Whipple’s disease).

The human microbiome

Me, myself, usLooking at human beings as ecosystems that contain many collaboratingand competing species could change the practice of medicine

The human microbiome

Me, myself, usLooking at human beings as ecosystems that contain many collaboratingand competing species could change the practice of medicine

Aliens Inside Us: A (Mostly Friendly) Bacterial Nation

New School

2006

2007

2006

2005

2007

20012004

> 2007‐ NIH created the Human MicrobiomeProject to span 5 years and $150 million

> Europe and China joined to form MetaHIT Consortium

> 2012‐ Conclusion of HMP. Series of reports in Nature, PloS One, Science.

> 2013‐ HMP 2.0?

2

Joslin Diabetes CenterPrimary Care Congress for Cardiometabolic Health 2013The GI Tract in the Etiology of the Cardiometabolic Syndrome

Copyright © 2013 by Joslin Diabetes Center, Inc. All rights reserved. These materials may be used for personal use only. Any distribution or reuse of this presentation or any part of it in any form for other than personal use without the express written permission of Joslin Diabetes Center is prohibited.

The gut mucosa is our only protection from the outside world

Food particles

Bacteria, virus, fungi Toxins

Microbial byproducts

> There are more bacteria in our guts than cells in our entire body

> Dense microbial community interacts with your largest immune and endocrine organ

> Acquired from the environment from birth onwards

> Educates your immune system

> Breakdown otherwise indigestible dietary components

A hundred trillion of your closest friends

…but you must treat your friends well

Microbial influences on cardiometabolism

> Bacteria are absolutely required for energy harvest in the gut

Backhed et al. PNAS (2004)

• High fat feeding increases gut permeability

• Chronic permeability leads to impaired metabolism 

(Cani et al, Diabetes 2008).

• Type 2 diabetics exhibit a unique microbial profile similar to individuals with chronic gastritis (Qin et al. Nature 2012)

> Does Type 2 Diabetes start in the gut?

Microbial influences on cardiometabolism

Whatever is Driving the Autoimmunity Underlying Type 1 Diabetes Begins Early in Life

Geneticsusceptibility

% I

slet

Cel

l Ma

ss

100

50

0

IncitingEvent(s)

“Brittle”Diabetes

Time (years)

“Silent” �Cell Loss

DiabetesOnset

A microbial fingerprint for Type 1 Diabetes risk?

Microbial influences on cardiometabolism

Dumas et al.PNAS (2006)

Pluznick et al.PNAS (2013)

Koeth et al.Nat Med (2013)

3

Joslin Diabetes CenterPrimary Care Congress for Cardiometabolic Health 2013The GI Tract in the Etiology of the Cardiometabolic Syndrome

Copyright © 2013 by Joslin Diabetes Center, Inc. All rights reserved. These materials may be used for personal use only. Any distribution or reuse of this presentation or any part of it in any form for other than personal use without the express written permission of Joslin Diabetes Center is prohibited.

Koenig et al. PNAS (2010),

Diet shapes gut bacterial profile in humans

> Burkina Faso, AfricaDietary intake, ages 1‐6

• 672.2 ‐ 996.1 kcal/d

• Protein: 30.9 ‐ 40.2 g/d

• Fat: 18.9 ‐ 31.2 g/d

• Carbohydrates: 102.6 ‐ 148.6 g/d

BacteroidetesBacteroidetes

FirmicutesFirmicutes

BacteroidetesBacteroidetes

FirmicutesFirmicutes

De Filippo et al. PNAS (2010)

> EU, ItalyDietary intake, ages 1‐6

• 1068.7 – 1512.7 kcal/d

• Protein: 41.9 – 66.7 g/d

• Fat: 56.1 – 73.9 g/d

• Carbohydrates: 190.0 – 290.0 g/d

Genetic susceptibility

Immuneresponse

Environmentaltriggers

Luminal and Microbial adjuvants

Multiple hits creating the perfect storm

Cardiometabolicdiseases

Characteristics of the American diet(NHANES, 2001)

> 2,618 kcal/d

> 49% carbohydrate

> 15.5% protein

> 32.8% fat

> 10.9% saturated fat (of total kcal)

Study DietsLow-fat

(AIN-93M)Saturated-

Milk FatSaturated-Lard Fat

PUFA(Safflower oil)

Fat (%kcal)-Saturated (%total)-PUFA

ProteinCarbohydrateMicronutrients/Fiber

50.63.9

1966

*ND

38653.5

1647

*ND

383911

1647

*ND

38978

1647

*ND

Can dietary fat alter the enteric microbiome?

LF PUFA MF

> C57BL/6 mice fed three diets for 21 days

Devkota et al. Nature (2012)

% in

cide

nce

of c

oliti

s

Time (weeks)

MF

PUFA

LF

> IL10‐/‐mice fed three diets for 21 days

Arumugam et al. Nature (2011)

> Low‐abundance species with high function?

4

Joslin Diabetes CenterPrimary Care Congress for Cardiometabolic Health 2013The GI Tract in the Etiology of the Cardiometabolic Syndrome

Copyright © 2013 by Joslin Diabetes Center, Inc. All rights reserved. These materials may be used for personal use only. Any distribution or reuse of this presentation or any part of it in any form for other than personal use without the express written permission of Joslin Diabetes Center is prohibited.

Bilophila wadsworthia? 

> Discovered in 1988 

> Bilophila = “bile‐loving”

> Sulfite‐reducing bacteria   (SRB‐ dsrA)

> Input sulfite, output H2S

> Often recovered from a variety of infections (pathobiont)

> Bile must be the sulfite source

Key = Taurocholic acid

Diet-derived bile

MFLF PUFA

% T

auro

chol

ate

of total bile

***

Op

tical d

en

sity

MF Bile

PUFA BileLF BileControl Media

Time (hrs)

Devkota et al. Nature (2012)

> A symbiont that turns pathogenic given the right stimulus

> Present in healthy individuals

> These bacteria have evolved the ability to survive harsh environments

What is a pathobiont?

Complications of modern society

> Antibiotic overuse

• MRSA

> Hospital acquired infections

• C. difficile

> The “hygiene hypothesis” and autoimmunity

• Food allergies

B. wadsworthia induces TH1-mediated colitis

a

c bc bcbc

b

a

bb

ccc

a

bbcbcbcc

LF + Bw MF + Bw0% 0%

PUFA + Bw23%

MF + Bw

CD4

IFN

-γ

CD4

Isot

ype

0% 0% 28%

Devkota et al. Nature (2012)

% C

D4+

IFNγ+

cel

ls

**

LF + Bw

PUFA + Bw

MF + Bw

Num

ber

of I

FNγ

prod

ucin

g C

D4+

cel

ls (

105)

**

LF + Bw

PUFA + Bw

MF + Bw

Can we re‐shape the gut microbiotathrough diet?

Design:

1. SPF IL10‐/‐mice fed 4 diets for 8 weeks:

Low‐fat  High Saturated‐fatHigh Saturated‐fat + 5% fish oil High Saturated‐fat + 5% safflower oil 

2. Germ‐free IL10‐/‐mice monoassociated w/ B. wadsworthia and fed test diets for 4 weeks

5

Joslin Diabetes CenterPrimary Care Congress for Cardiometabolic Health 2013The GI Tract in the Etiology of the Cardiometabolic Syndrome

Copyright © 2013 by Joslin Diabetes Center, Inc. All rights reserved. These materials may be used for personal use only. Any distribution or reuse of this presentation or any part of it in any form for other than personal use without the express written permission of Joslin Diabetes Center is prohibited.

Omega‐3 supplementation inhibits bloom of Bw in SPF IL10‐/‐ mice

0102030405060708090

100

Bacteroidetes

Firmucutes

Proteobacteria

Cyanobacteria

Actinobacteria

Tenericutes

LF MF MF + -3 MF + -6

% B

.wad

swor

thia

LF MF

MF +

ω-6

MF +

ω-3

0

1

2

3

4

5*

*

#LF MF

MF +

! -6

MF +

! -30

1

2

3

4C

oliti

s S

core

***

*

#

LF MF

MF +

ω-6

MF +

ω-3

0

50

100

150

pg/m

L IF

N * *

#

LF MF

MF +

ω-6

MF +

ω-3

0

200

400

600

800

pg/m

L IL

12p7

0

*

*

#

LF MF

MF +

ω-6

MF +

ω-3

0

50

100

150

200

pg/

mL

IL6 *

#

LF MF

MF +

ω-6

MF +

ω-3

0

200

400

600

800

pg/m

L IL

17 *

#

Bw growth and inflammation is attenuated by omega‐3 supplementation

LF MF

MF +ω-6

MF +

ω-3

0.0

0.5

1.0

20

40

60

80

100

120

Rel

ativ

e fo

ld c

hang

e (d

srA

)

*

*

#

CD4

IFN

-γ

10% 5% 1%

CD4

Isotyp

e

MF MF + ω -6 MF + ω -3

>Current drug therapy for diabetes is poor and narrowly focused

>Targeting bacterial populations and intestinal inflammation offer new avenues for treating and curing metabolic diseases.

-------------------------------------------------------------------------------------

>Pathobionts: Understand the triggers that turn a benign bacteria into a pathogen

>Prebiotics:  Develop nutrient therapy that selectively eliminates harmful bacteria or promotes growth of beneficial bacteria.

>Probiotics:  Design robust bacterial cocktails tailored to an individual’s microbiome.

The future of personalized medicine:Prebiotics, Probiotics, and Pathobionts

Clinical Implications

> The intestinal microbiota are absolutely required for intestinal health and homeostasis

> Dysbiosis results from an array of external influences, namely diet and antibiotics, that can provide fertile ground for pathobiont expansion

> In the presence of pathobionts, the intestinal barrier may become compromised, leading to luminal antigens passing through systemic circulation

> This phenomena is responsible for an array of inflammatory diseases and may explain others of unknown origin

Future therapies for treating systemic inflammation must begin to consider re‐shaping the gut microbiota

Acknowledgements

Joslin Diabetes CenterSteven ShoelsonJongsoon Lee

The University of ChicagoEugene ChangBana Jabri

Matthew BradyChris RhodesMark MuschYunwei WangVanessa Leone

Anuradha NadimpaliHannah Fehlner‐Peach

Romain BouziatDigestive Diseases Research 

Core CenterCommittee on Molecular Metabolism and Nutrition

Argonne National LaboratoryDionysios Antonopoulos

Folker MeyerJack Gilbert

Michigan State UniversityJames TiedjeMarius Vital

UCLA‐Wadsworth VASidney Finegold

UCSDLee Hagey

Alan Hofmann

Questions?

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