The Role of Food in the Functional Gastrointestinal Disorders H. Vahedi, MD. Gastroentrologist Associate professor of medicine DDRI 92.4.27 vahedi@ams.ac.ir
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
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 The American Journal of GASTROENTEROLOGY VOLUME 108 MAY 2013; 728-736
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 The American Journal of GASTROENTEROLOGY VOLUME 108 MAY 2013; 728-736
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 The American Journal of GASTROENTEROLOGY VOLUME 108 MAY 2013; 728-736
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 The American Journal of GASTROENTEROLOGY VOLUME 108 MAY 2013; 728-736
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 Polyols (FODMAPs) in patients with IBS or IBD 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 The American Journal of GASTROENTEROLOGY VOLUME 108 MAY 2013; 737-747
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 The American Journal of GASTROENTEROLOGY VOLUME 108 MAY 2013; 737-747
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 The American Journal of GASTROENTEROLOGY VOLUME 108 MAY 2013; 634-641
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)