Dietary Interventions to Prevent a Leaky Gut

Dr. Jennifer Monk

Assistant Professor Department of Human Health & Nutritional Sciences

University of Guelph

What is Gut Health?

• Positive aspects of gastrointestinal (GI) tract function, such as:

– effective digestion and absorption of food

– absence of GI illness

– immune function

– Focus on the colon (gut)

• Gut Health Interface

– Gut Microbiota (bacteria)

– GI barrier (human cells next to the microbiota)

• Impair gut health development of diseases

Nagpal et al., 2014, Front Med GI Barrier

&

What is the Gut Microbiota?

• Gut = colon or large intestine

• Microbiota = collection of all bacteria (or microbes) living in/on the human body

• 200-500 different species of bacteria per person

• Microbiota composition and size changes throughout the GI tract (mouth colon)

• The biomass of the microbiota is in the colon

Symbiotic Relationship Between the Human Body and the Microbiota

The human body exists in a delicate balance with our bacteria

Maintaining balance is central to preventing disease

Da Silva et al., 2017

Our health depends on the health of our microbes

• Bacteria/microbial cells outnumber

human cells by approximately 3:1

• Bacteria influence how the body functions…it can promote health or promote disease development

https://www.amnh.org/explore/science-topics/microbiome-health/meet-your-microbiome

FEMS Microbiol Rev. 20160 Jan; 40(1): 117–132.

Microbiota Impacts Many Physiological Functions

Obesity and

Insulin Resistance

Inflammation

Environmental Factors Impacting the Gut Microbiota

Sommer et al., Nature Reviews Micro, 2013

Balance Promote Heath &

Physiological

Function

Promote Disease

Dysbiosis

(out of balance) Microbiota Composition

Altered Gut

Microbiota

Dietary Components Influence the Gut Microbiota

Gut Microbiota

DYSBIOSIS PROMOTE

HEALTH

Obesity/Insulin

Resistance

High Fat Diet Fruits and Vegetables

Pulses Whole Grains Artificial Sweeteners

-

-

+

+

+

Yogurt

Dairy Products

+

The GI Barrier: the other side of Gut Health

Single cell barrier separating the external environment and microbiota from the rest of the body.

Defense of this single cell barrier is critical!

• PIC

Van den Bossche et al., 2017

microbiota

The GI Barrier & the Microbiota: a Critical Gut Health Interface

Epithelial Cell/Colonocyte

Microbiota

GI Barrier Components

Anti-microbial

proteins (AMPs)

Microbiota

Mucus Layer (made up of mucins)

Hold barrier cells tightly together

Single cell thick GI Barrier

Physical Separation of Microbiota from the GI Barrier

Maynard et al., Nature, 2012

www.biokplus.com

What Happens When the GI Barrier Fails?

How Can We Improve our Gut Health?

1. Change the composition and function of the microbiota

2. Improve the function of the GI Barrier Less leaky More mucus

Anti-microbial

proteins

(AMPs)

Microbiota

Mucus Layer (made up of mucins)

Holds barrier cells tightly together

Single cell thick GI Barrier

3. Both

Maynard et al., Nature, 2012

Can Our Nutritional Choices Influence Gut Health?

Danneskiold-Samsoe et al., Food Res Int, 2019

Food Components

Carbohydrates Proteins

Lipids Phenolic

Compounds

Producing

SCFA BCFA

TRP-metabolites Secondary Phenolics

Gut Health Interface

Health Effects

Dietary Components that Reduce Leaky Gut

• Phenolic Compounds

– Catechins apples, dark chocolate, blackberries, cherries

– Quercetin leafy vegetables, broccoli, red onions, peppers, apples, grapes

– Epicatechin green tea, apples, cocoa products, red wine

– Caffeic acid coffee, berries, apples, artichokes

– Resveratrol red wine, red grapes

– Isoflavones soybeans, chickpeas, fava beans, pistachios, peanuts,

Monk et al., JNB, 2015-2020; Piegholdt et al., FRBM, 2014; Noda et al., 2012; Kullamethee et al., PNS, 2013; Mayangsari et al., JFF, 2018; Suzuki et al., J Nut, 2009

• Omega-3 fatty acids - EPA/DHA fatty fish, available in supplements

• Fiber

- Soluble fiber - Oligosaccharides

Dietary Sources of Fiber

• Fiber can be found in:

– Fruits and Vegetables

– Legumes/pulses: dried beans, lentils, peas, soybeans

– Nuts and seeds

– Whole grains (“brown”): breads, cereals, crackers and pasta, brown rice, hulled barley, oats

Smolin et al., Nut, Sci App, 2015

Liver Artery

Intestine Effect of Dietary Fiber

• ↓ Total Cholesterol

• ↓ LDL-cholesterol

• ↓ CVD risk

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For every 7 g dietary fiber/day DECREASES CVD risk by 9%

Fiber Cholesterol

Beneficial Health Effects of Fiber

Smolin et al., Nut, Sci App, 2015

• Slows passage of food through GI tract

• Slows the absorption of nutrients in the GI tract

• Increases satiety = feeling “full” longer

• Slows glucose absorption

• ↓ fluctuations in blood glucose

• Improves bowel regularity

(↓ constipation)

• ↓hemorrhoids

• ↓ diverticulosis/diverticulitis

• ↓ risk of colon cancer

High Fiber Intake Low Fiber Intake

Time after eating

Blo

od

Glu

cose

Low soluble fiber meal

Soluble fiber-rich meal

How Dietary Fiber Can Improve Gut Health

https://www.thinkbiome.com/postbiotics Epithelial Cell/Colonocyte

Tight Junctions

https://www.thinkbiome.com/postbiotics

http://www.pulsecanada.com/about-pulse-canada/what-is-a-pulse/

Dried edible seeds that grow inside a pod

Pulses are lower in fat versus soybeans and peanuts

Dietary Pulses

• Affordable

• Nutrient Dense – Low fat

– High protein

– High fiber

– High in vitamins and minerals

• Example: one cup of beans (~2/3 can) = ~12 g fiber…HALF the daily recommended fiber intake

http://www.pulsecanada.com/about-pulse-canada/what-is-a-pulse/

Chronic Conditions in Canadian Adults: Leaky Gut Plays a Role

https://www.canada.ca/en/public-health/services/chronic-diseases/prevalence-canadian-adults-infographic-2019.html

Metabolic Syndrome

Obesity

High Triglycerides

Low HDL cholesterol

“good cholesterol” Hypertension

High blood glucose

Metabolic Syndrome

“Dyslipidemia”

CLUSTER of inter-related conditions that INCREASE RISK of developing: • Atherosclerosis • Heart Attack • Stroke • Type 2 Diabetes

“Hyperglycemia”

CVD

Chronic INFLAMMATIONN

If you answered “Yes” to 2 questions, you may be at risk of developing metabolic syndrome. If you answered “Yes” to 3 or more questions, you may have metabolic syndrome.

Metabolic Syndrome Prevalence

18-39 40-49 50-59 60-69 70-79

Age (years)

40% 40%

20%

% o

f th

e P

op

ula

tio

n

0%

https://www.metabolicsyndromecanada.ca/

https://infophentermine.com/body-mass-index/

How do We Assess Overweight/Obesity

Classified based on Body Mass Index (BMI)

BMI

Higher the BMI, higher the CVD risk

Severely Obese

Morbidly Obese

Adipose

Tissue

Ser

um

LP

S

Lean Obese Inflammatory Mediators

Insulin

Sensitivity

Adipose Tissue (local) and

Systemic Inflammation

Gut Microbiota

Cancer

Hypertension

Cardiovascular Disease

Type 2 Diabetes

LPS How does the microbiota contribute

to the development of obesity?

Obese Inflammatory Phenotype

Amar et al. J Clin Nutr, 2008

Insulin

Resistance

Goblet

Cell

Tight

Junctions

Mucins Mucus

Layer

HEALTHY OBESE

Blood

The Gut Health Interface Changes in Obesity

1. Changes in Gut

Microbiota

2. LOSS of mucus

and tight junctions

3. Increased GI

Barrier

Permeability

(Leaky Gut)

Gut

Microbiota

Epithelial

Cell

4. LPS and other bacteria

components enter the blood

stimulating inflammation and

metabolic dysfunction

Take Home Messages

• Gut Health comprises the function of BOTH the microbiota and GI barrier

• Improving GI barrier function can reduce the severity of many chronic diseases

• Our nutrition or dietary choices can profoundly impact gut health

• Eat more fiber!