the role of food in the functional gastrointestinal...

The Role of Food in the Functional

Gastrointestinal

Disorders

H. Vahedi , MD . Gastroentrologist

Associate professor of medicine

DDRI

92.4.27

[email protected]

Disorder Sub-category

A. Oesophageal disorders A1. Functional heartburn

A2. Functional chest pain of presumed

oesophageal origin

A3. Functional dysphagia

A4. Globus

B. Gastroduodenal disorders B1. Functional dyspepsia

B1a. Postprandial distress syndrome

B1b. Epigastric pain syndrome

B2. Belching disorders

B2a. Aerophagia

B2b. Unspecified excessive belching

B3. Nausea and vomiting disorders

B3a. Chronic idiopathic nausea

B3b. Functional vomiting

B3c. Cyclical vomiting syndrome

B4. Rumination syndrome in adults

C. Bowel disorders C1. Irritable Bowel Syndrome

C2. Functional abdominal bloating

C3. Functional constipation

C4. Functional diarrhoea

C5. Unspecified functional bowel disorder

Pathogenesis of FGIDs:

-incompletely understood

-visceral hypersensitivity

-genetic factors

-low grade inflammation

-intestinal dysbiosis

-and brain–gut axis dysfunction

-Food is associated with symptom onset or exacerbation

in a significant proportion of FGID patients

-In management of FGID patients, diet has largely

played an adjunctive rather than a primary role

-Food plays a critical role in determination of the host microbiome

-Food has an even greater role in shaping the gut microbiome than genetics

-Alterations in gut immune function can be identified in a subset of IBS sufferers

-Increased numbers of mast cells, lymphocytes, and or eosinophils have been identified in some IBS patients

The American Journal of GASTROENTEROLOGY VOLUME 108 | MAY 2013; 694-697

• Any abnormal reaction resulting from the ingestion of a

food is considered an adverse food reaction

• Such reactions may be the result of:

-food allergies

-or food sensitivities

-or intolerances


FOOD SENSITIVITY

• Some patients with IBS report worsening of symptoms

after eating some food

• Studies focused on IgG antibodies have shown that

eliminating specific foods in patients who have elevated

IgG titers associated with those food antigens may reduce

IBS symptoms

• Investigations have centered on food specific antibodies,

carbohydrate malabsorption, and gluten sensitivity

FOOD ALLERGIES

• Food allergies are arise from specific immune responses occurring reproducibly on exposure to a specific food

• The primary dietary sources of proteins are muscle, milk, egg and plant proteins

• Muscle proteins originate from meat products, including red meat, fish, and poultry

• Milk proteins are represented by two major groups: caseins and whey proteins

• Egg proteins are morphologically divided into proteins of egg white (albumen) and yolk

• Plant proteins include cereal, and legume proteins

• The term “ allergy ” includes clinical conditions

associated with altered immunologic reactivity that

may be IgE-mediated or non-IgE-mediated

• These reactions are involved in the pathogenesis of

many cases of:

-asthma

-rhinitis

-urticaria

-atopic dermatitis

-and GI adverse food reaction

• There are additional immunologic, non-IgE-induced

mechanisms, including:

-eosinophilic GI disorders (EOE, eosinophilic

enteritis, eosinophilic colitis, and eosinophilic

gastroenteritis)

-food protein enteropathy

-enterocolitis and proctitis

-and celiac disease

-which are also considered to be food allergies

The American Journal of GASTROENTEROLOGY VOLUME 108 | MAY 2013;728-736

NON-CELIAC GLUTEN SENSITIVITY

• Gluten is a; water-soluble proteins from wheat, rye, and

barley

• “ Gluten-related disorders ” is a term used to describe all

conditions related to gluten, including:

-celiac disease

-dermatitis herpetiformis

-gluten ataxia

-and nonceliac gluten sensitivity (NCGS)

The American Journal of GASTROENTEROLOGY VOLUME 104 JUNE 2009

• NCGS can be characterized by GI symptoms, such as:

-diarrhea

-abdominal discomfort, or pain

- and bloating and flatulence,

-or EIM, such as:

=headache

=lethargy

=hyperactivity disorder

=ataxia

=or recurrent oral ulceration

=which improve or disappear after

gluten withdrawal in patients in whom celiac disease and wheat

allergy have been ruled out


Is it IBS, celiac disease, or something in between?

• NCGS; a collection of medical conditions in which gluten leads to an

adverse food reaction

• NCGS; clinically indistinguishable from celiac disease, and testing is

negative or inconclusive

(One study suggests that increased AGA-ab IgG are often found in

patients with NCGS)

• NCGS may be one of the underlying mechanisms for symptom

generation in IBS

• NCGS; some authors may, belong to the spectrum of celiac disease


• Another proposed mechanism is the

“ leaky gut ” hypothesis

• Other mechanisms have been proposed for

NCGS, although there is scant scientific

literature supporting the:

-hypotheses of gluten toxicity

-immune complex-mediated mechanisms

-and autoimmunity


Fiber in FGID:

• Fibers are partial or total fermentation in the distal small

bowel and colon leading to the production of SCFAs and

gas, thereby affecting gastrointestinal function and

sensation

Types of Fiber

• The fermentability and solubility of different "fiber" types

relates closely to their chemical composition (e.g.,

presence of cellulose, hemicellulose, gums, resistant

starch, lignins, pectins)

Am J Gastroenterol. 2013;108(5):718-727

FODMAPs

Fermentable Oligo-, Di-, and Monosaccharides And

in patients with IBS or IBD )FODMAPs( olyolsP

enter the distal small bowel and colon where they

are fermented, leading to:

-symptoms

-and increased intestinal permeability

-and possibly inflammation

BEHAVIOR OF DIETARY LIPIDS IN THE GI LUMEN

Lipids are a group of chemical compounds that

include:

-TGs; the most abundant lipids in the body

-mono and di-glycerides, and fatty acids

-cholesterol

-phospholipids

-and sterols


SCFAs ( < 8 carbon atoms) are

generated by colonic bacteria in the

process of fermentation of unabsorbed

carbohydrates

These are an important source of energy

for:

-colonocytes

-colonic microbiota

Intraduodenal infusion of a long-chain TG emulsion

(Intralipid ® ) induces markedly greater symptoms,

including:

-fullness

-nausea

-and bloating; in patients with FD than healthy

-slow transit of intestinal gas

-and due to an inhibition of small bowel motor activity

-and also exacerbates symptoms induced by gastric

distension

IBS-C patients predominantly experienced

rectal distension as pain

IBS-D patients predominantly experienced

rectal urgency

Lipids exacerbate rectal hypersensitivity in

IBS patients

CCK potently enhances:

-colonic motility

-and gastrocolonic reflex

Data suggest that CCK antagonism increases intestinal capacitance and reverts lipid-induced hypersensitivity

Role of CCK 1 receptor antagonists in the treatment of FGIDs


Self-Reported Food-Related Gastrointestinal

Symptoms in IBS Are Common and Associated With More Severe Symptoms and

Reduced Quality of Life

The aims of this study were to determine which food groups and specific food items IBS patients report causing GI symptoms


METHODS:

We included 197 IBS patients (mean age 35

years; 142 female) who completed a food

questionnaire in which they specified

symptoms from 56 different food items or food

groups relevant to food intolerance / allergy

The patients also completed questionnaires to

assess depression and general anxiety, IBS

symptoms, somatic symptoms, and quality of

life (IBS Quality of Life Questionnaire)

RESULTS:

In all, 84 % of the studied population reported symptoms related to at least one of the food items surveyed

Symptoms related to intake of food items with incompletely absorbed carbohydrates were noted in 138 (70 % ) patients; the most common were:

-dairy products (49 % )

-beans / lentils (36 % )

-apple (28 % )

-flour (24 % )

-and plum (23 % )

-GI symptoms were also frequently reported after intake of fried and fatty foods (52 % )

-Hot and spicy foods may also trigger symptoms in IBS

-A lot of these spices contain capsaicin, an alkaloid responsible for the hot taste of peppers

-More than 40 % of the patients in this study experienced GI symptoms after intake of capsaicin-containing food items

-Capsaicin has been found to provoke visceral pain and hypersensitivity in functional GI disorders

-It may be advisable to inform IBS patients about the potentially

negative properties of capsaicin

-Women tended to report more food items causing symptoms than men ( P = 0.06)

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