NS Exam 2

What are the common causes of disease in the esophagus?

Changes in digestion, absorption, secretion, or motility
Genetic malignancy
Immune function

Define GERD.

Backward flow of acidic stomach contents into the esophagus

What are the symptoms of GERD?

Heartburn
Ulcers and scar tissues
Dysphagia (difficulty swallowing)
Increased salivation
Hoarseness
Belching
Pain in back, neck, or jaw

What is the etiology of GERD?

Hiatal hernia

Reduced LES pressure (allows relaxation)— ex. Smoking, pregnancy, smooth muscle relaxants; foods: chocolate, peppermint, alcohol, caffeine, and high-fat foods

Increased abdominal pressure— obesity and tight clothes

Delayed gastric emptying- high fat diet

Recurrent vomiting

What is Hiatal Hernia?

Pressure generated by diaphragm forces acidic contents into the esophagus (increased risk of GERD)

What are the complications of GERD?

Chronic inflammation can lead to Barrett's esophagus with premalignant cells and increased risk of adenocarcinoma of the esophagus

Describe MNT and its rational for GERD.

Avoid large, high fat meals (take longer to break down than other foods) 3-4 hrs before lying down

Avoid foods high in acid, fat, or spice as well as peppermint, chocolate, alcohol, and caffeine

Obesity is highly associated with GERD— weight loss recommended

Outline GERD medical management.

Elevate head of bed (in hospital)
Drug treatment
Surgical intervention- Nissen Fundoplication (wrap Fundus around LES to provide additional strength to LES)

What are the drugs used for acid suppression?

Antacids- Ca, Mg, and Al

Foaming agents (create physical barrier)

H2 receptor antagonists (block histamine)

Proton pump inhibitors (suppress acid production)

Prokinetics (increase stomach motility)

What are the mechanisms of acid secretion?

Gastrin- stimulates histamine release
Histamine- Stimulates acetyl choline which stimulates the release of H+ (HCl)

Describe EoE.

Chronic immune-mediated inflammatory disorder characterized by symptoms of esophagus Dysfunction and histological evidence of eosinophil-predominant inflammation in esophageal mucosal biopsies

In summery its really a severe allergy response in the esophagus

What are the symptoms of EoE?

Note: Most common cause of esophageal symptoms amount children and young adults

Heartburn, no cardiac chest pain, Dysphagia, and food impaction

How is EoE treated?

High does proton pump inhibitors, steroids, and diet intervention

What are the best dietary treatments of EoE?

Elemental diet (pre-digested foods) with amino acid formula
Elimination of cows milk, soy, eggs, wheat, legumes, tree nuts, and seafood

Why can the designation of "medical food" be used for specialized foods used to treat EoE?

Elimination of allergens
Elemental diet

What macronutrients undergo digestion and absorption in the stomach?

Macronutrients
Alcohol
Some water

What are the major secretions of the stomach? Where do they come from?

Gastric juice: water, mucus, HCl, enzymes, and electrolytes
Parietal cells- HCl and intrinsic factor
Chief cells- pepsinogen and lipase
Enterochromaffin-like cells- histamine

What are the functions of HCl?

Turns Pepsinogen into pepsin
Denatures protein
Bacteriostatic (decrease harmful bacteria)
Releases B-12 from food
Increase solubility of Ca and Fe

Define dyspepsia (symptoms, causes, treatment).

Indigestion (upper GI discomfort)- vague abdominal pain, bloating, nausea, regurgitation-vomiting, and belching

May be benign or symptoms of underlying problems such as GERD

May also be due to diet and stress

Dietary treatment: avoid overeating and drinking, chew thoroughly and eat slowly (sensible eating)

Define gastroparesis (symptoms, causes, treatment).

Delayed gastric emptying due to damage to vagus nerve which controls peristalsis

Symptoms: Anorexia, nausea, vomiting, early satiety, abdominal pain, erratic glycemic control

Causes: Type 1 diabetes or surgery (stomach shuts down)

Treated with medications such as metoclopramide or in some cases with gastro electrical stimulation to induce peristalsis

What is the MNT for gastroparesis?

Small frequent meals
Low fat foods
Low fiber foods
Make sure nutritional needs are still being met

What are the two types of gastritis?

Acute- H. pylori, alcohol, food poisoning, NSAIDs

Chronic- increases with age, achlorhydria (lack of HCl secretion)

Define gastritis (symptoms, causes, treatment).

General term for inflammation and tissue damage from erosion of mucosal layer of stomach

Symptoms: belching, anorexia, abdominal pain, vomiting

Causes: related to infection (viral, bacterial/H. pylori, fungal, or parasitic); can also be related to alcohol and medication (NSAIDs) ingestion

Define peptic ulcer disease

Involves ulceration of the gastric or duodenal mucosa that penetrate the submucosa (multiple layers of stomach effected) due to erosion through the mucosa and submucosa causing GI bleeding (seen in melena-black tarry stools), hemorrhage and/or perforation

What are the symptoms of PUD?

Symptoms: epigastric pain and burning sensation, melena (black tarry stool)

What causes PUD in most cases?

Most commonly caused by H.Pylori infection

How is PUD diagnosed and treated?

Diagnosed by endoscopy with biopsy
Drug treatments 3-4 meds to treat H. Pylori infection, medications to suppress acid secretion (antacids and cytoprotective agents)

What populations are at risk for H. Pylori infections?

More than half the world's population is infected- relates to poor hygiene status

What is the MNT for PUD?

• Diet not a cause of PUD

• Restrict foods now to increase acid secretions or cause irritation to mucosa (caffeine and coffee, decaf or regular, alcohol, black and red pepper)

• Acidic foods are allowed

• Frequent small meals (6-8 meals/day)

What is vagotomy?

- Partial or total severance of the vagus nerve (controls peristalsis and secretions)
- Decreases cholinergic stimulation and acid production

What is pyloroplasty?

Enlargement of the pyloric sphincter (let food move through faster)

What is partial gastrectomy with Billroth I or II?

• Billroth I = top half of stomach is reconnected to duodenum (less invasive)

• Billroth II = top half of stomach is reconnected to the Jejunum (remove the are with hem orange/ulcers in PUD), like Roux-en Y but no pouch made

What is roux-en-Y bypass?

• Bariatric surgery

• Not as common in treating GI issues; usually to treat obesity

What is the major complication seen with gastric surgery? What are the symptoms?

• Dumping syndrome- food enters the small intestine to quickly, causing fluid to move in quickly to dilute the high osmotic load

• Early symptoms: 10-20 min. After eating; decrease in blood volume = dizzy, weakness, and rapid heart rate

• Intermediate symptoms: 20-30min after eating; abdominal distention, bloating, flatulence, pain, and diarrhea

• Late symptoms: 1-3 hrs after eating; Reactive hypoglycemia after eating simple CHO die to rapid absorption of glucose and release of insulin (not really digesting, but still sensing the amount of CHO)

What is the MNT for dumping syndrome?

• Small meals throughout the day

• Lying down and avoiding activity an hour after eating

• High-protein, moderate fat foods, complex carbs (acid simple carbs)

• No liquid with meals (will increase GI transit)- small amounts of fluid during day, 1 hr after meal

What are the causes of malabsorption?

• Defect in digestion (gastric resection, pancreatic enzymes and bile acids, brush border enzymes)

• Defect in absorption or transport (biochemical or genetic abnormality, mucosal structure damage, shorten length of intestines, shortened transit time)

• Defect in lymphatics and vascular system

• Bacterial over growth (main cause = slowed transit makes food into breeding ground)

• NOTE: main symptom is diarrhea

What is the definition of celiac's disease?

• Autoimmune disease in genetically suceptible individuals caused by immunological reaction to gluten

• Characterized by chronic inflammation, mucosal atrophy, and malabsorption triggered by gluten (not an allergy)

What are the types of malabsorption seen in celiac disease?

• Mucosal structure damaged (flattened) with immune response

• Loss of surface area

• Diarrhea = decrease in growth, wt. loss

What is the etiology of celiac's disease?

• Inappropriate T-cell mediated immune response caused by gliadin in genetically predisposed people (chronic inflammation of small intestinal mucosa

• Production of IGA anti tissue transglutaminase (anti-tTG) (seen in biopsy), antiendomysial (EMA) and anti gliadin (AGA) antibodies (Used as diagnostic indicators)

How is celiac's disease diagnosed?

• Biopsy (anti-tTG)

• Antibodies (EMA and AGA)

• Gold Standard: small bowel biopsy

• Positive Screen → Biopsy → Damage → GF diet → Biopsy → no more symptoms

• Also can look for positive genetic markers (but this is not equal to a definite diagnosis)

• Note: being gluten free before screening can show a false negative

The sensitivity of tTG antibody testing is 90% and 95% respectively. What does this mean?

Indicator of a positive celiac's screening

What are the GI symptoms of celiac's?

• Diarrhea (decreased growth, weight loss)

• Abdominal pain, bloating, cramping, and gas

What are the non-GI symptoms of celiac's?

• Dermatitis

• Anemia

• Joint pain, arthritis

• Muscle cramps

• Dental enamel hypoplasia

• Osteopenia or osteoporosis

• Delayed puberty

• Infertility and miscarriages

• Depression

• Fatigue

• Mouth sores

• Head ache

What is gluten and gliadin?

• Protein in wheat, rye, malt, and barley

• Gliadin is resistant to digestion, so it stays in lumen and can cause inflammation

What foods contain gluten?

Wheat, rye, malt, barley

Describe the MNT for celiac's disease.

• Lifelong gluten free diet (gluten foods and cross contaminates like oats); may als restrict lactose (secondary malabsorption)

• Symptoms improve by 2-8 week in 70% cases

• Restore nutritional status, vitamin-mineral supplement is often needed

What nutrients may be limiting in a gluten-free diet?

Nutrients that are found in enriched grains

Differentiate between non-celiac gluten sensitivity and celiac disease.

• Gluten sensitivity is not an autoimmune response (no antibodies); possibly a subset of IBS

• No genetic link

• Celiacs is 2:1 females:males; sensitivity is 3:1

• Celiacs can occur at any age; gluten sensitivity rare in children

What are some difficulties with the gluten free diet?

Some foods have "hidden gluten" from cross contamination

What does FDA define as gluten-free?

What is IBS?

Bowel disorder characterized by abdominal pain related to defecation or a change in bowel habit

How is IBS diagnosed?

• Diagnosed using the Rome IV criteria in the prior 6 months

• Abdominal pain or discomfort that is present at least one day a week for 3 moths and associated with at least two of the following: pain relief with defecation, pain associated with change in frequency of stool, pain associated with change in form of stool

What is the etiology of IBS?

• Largely unknown

• Functional diagnosis: diagnosis is made after ruling out all other causes of patient's symptoms

• Symptoms are aggravated by stress and emotional trauma (gut-brain axis)

• Greater sensitivity to serotonin (abnormal motility)

• Elevated response to infection (dysbiosis)

How does the microbiota affect human health?

- Composition effects:
- Obesity and Diabetes
- IBS
- Neurodegenerative disorders (Obesity and diabetes, IBS, efficacy of ketogenic diet)

- What is the gut-brain axis?

• Enteric and central nervous systems have cross talk

• IBS increases risk of neurologic disorders

What is the MNT for IBS?

• Establish regular eating pattern and avoid large meals

• Identify food intolerances (triggers)- elimination diet: FODMAPS, high fat, caffein, lactose, caffeine, alcohol, sorbitol, gas producing foods (beans, peas, cabbage, and bran) and fructose

• Peppermint oil- reduces abdominal pain

• Prebiotic, probiotic, and symbiotic

- What is gut dysbiosis? How might it affect IBS?

• Imbalance of the gut; loss of diversity

• IBS causes the loss of beneficial microorganisms and the expansion of harmful ones

• Effects: increased permeability (less protection form pathogens), malabsorption, altered motility, sensitivity to pain with gas and water in gut, immune changes, changes in gut-brain axis

What is a prebiotic?

- Food for gut bacteria

What is a probiotic?

foods (typically high-fiber foods) that act as food for human microflora.

What is a symbiotic?

Organisms that help the beneficial microbes in the gut

What are FODMAPs? What are some high FODMAP foods?

• Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols

• Apples, milk, legumes, gluten grains, honey, fructose, onions, etc.

Compare a gluten free and FODMAP diet. Why are wheat, rye, and Barley eliminated on a low FODMAP diet?

• Wheat and Rye and Barley are all high in FODMAPS and contain gluten

• Gluten intolerance can contribute to IBS

What are the 3 phases of the FODMAP diet.

• Elimination

• Determine sensitivities and start reintroduction

• Personalization as needed for symptom management

Why do you reintroduce FODMAPs? How is this done?

• Low FODMAP diets reduces bifidobacteria and other beneficial bacteria that produce short chain fatty acids

• Stool pH increases with the diet- pathogens may grow

• FODMAPs have effects on microbiota diversity- many FODMAPS are prebiotics

• Reintroduce foods one at a time for 3 days and observe symptoms

What other issues other than IBS benefit from a low FODMAP diet?

• Endurance athletes with GI distress

• IBD with quiescent disease and IBS symptoms

• Celiac disease with IBS symptom overlap

How might FODMAPs trigger pain in IBS?

• CNS cross talk

• FODMAPS become SCFAs by microbiota draw water into LI and create gas causing discomfort

What are the causes of malabsorption?

• Defect in digestion

• Defect in absorption or transport

• Small intestine bacterial overgrowth

What are the causes of fat malabsorption?

• Lack of bile (liver disease, biliary tract obstruction,

• Ileal dysfunction (Lower reabsorption of bile acids), small intestine bacterial overgrowth

• Pancreatic disease, cystic fibrosis → lowers lipase

• Mucosal damage →impairs fat absorption (celiac, surgery, infection)

• Genetic disorders of metabolism (less chylomicrons)

How is fat malabsorption diagnosed? What about protein and carbohydrates?

• 72 hr fecal fat test = 100 g/d dietary fat and collect all stool for 3 days; >6g/d of fat in stool = steatorrhea

• Fecal N excretion reflects protein malabsorption (>6 g/day of N in stool = protein malabsorption

• Breath H2 test (lactose hydrogen breath test) = consume 25 g of lactose and measure breath H concentration (>20th suggest carbohydrate malabsorption)

Define steatorrhea and discuss its consequences.

• Fat in stool > 6g/d fat in stool

• Diagnosed with 72 hr fecal fat test, D-xylophone and Shillings test, or small bowel X-ray with barium swallow

• Consequences: energy loss of up to 40g/day (360kcal), diarrhea, lowered absorption of fat soluble vitamins, kidney stones, abdominal pain, and cramping

Define MCT and contrast its digestion and absorption with LCT.

LCT have to be broken down before absorption and MCT do not

MNT for fat malabsorption

- Restrict intake of long chain triglycerides (>12 carbons)
- Provide fat/energy with medium chain fatty aids (6-12 carbons) → provide 8.3kcal/g MCT
- Oral lipase supplement used in cystic fibrosis
- Treat deficiencies of fat soluble vitamins

Why is steatorrhea associated with renal calcium oxalate stones?

Oxalate-Ca is excreted in stool But the high amounts of fatty acids duet to malabsorption prevents Ca from binding so oxalate is reabsorbed causing kidney stones

How can you reduce the absorption of oxalate?

• Limit oxalate to < 50 mg/d and avoid foods high oxalate (spinach, black tea, nuts, etc.)

• Ca at each meal (150 mg) to bind to oxalate

• Low fat diet (<30% of energy from fat)

• Avoid large vitamin C supplements (converted to oxalate)

Define small intestine bacterial overgrowth. What causes it and how does it affect nutritional status?

• Cross contamination of bacteria from the colon due to weak illogical valve, fistula, IBS, or bariatric surgery

• Bacteria deconjugate bile acids = toxic to nucosa and Michelle formation (steatorrhea)

• CHO malabsorption (when bacteria ferment lactose)

• Bacteria use thiamin and B12 for their own growth

How do you treat SI bacterial overgrowth?

• MNT: MCT, lactose-free diet and vitamin/mineral supplements

• Medical Rx: treat cause (surgery may be needed) and control bacterial growth with antibiotic and pre/probiotics

Define fistula, how might it cause bacterial overgrowth?

• An abnormal opening in the stomach or intestines that allows the contents to leak; can be enteroenteric or enterocutaneous

• Severe complications; need surgical resection

What is the definition of diarrhea?

Watery stools at least 3 times per day (Major global health concern)

What are the effects of diarrhea?

• Acute: loss of water, HCO3, Na, K, Mg, and Cl; metabolic acidosis and dehydration

• Chronic: weight loss, micronutrient deficiencies

What are the three categories of diarrhea?

• Osmotic = high number of osmotically active particles that draw water into the gut; disappears with fasting

• Infectious = food poisoning, often bloody; persists with fasting

• Secretory = active secretion of water and electrolytes; large volume of non bloody diarrhea; persists with fasting

What are causes of the three types of diarrhea?

• Osmotic = high number of osmotically active particles that draw water into the gut (dumping syndrome, lactose intolerance, hyper osmotic enteral tube feeding

• Infectious diarrhea = food poisoning (campylobacter, E.coli, Salmonella, etc.)

• Secretory diarrhea = cholera toxin, C. Diff, etc.

How do you treat the three types of diarrhea?

• MNT: Manage fluid and electrolyte losses (oral rehydration solutions to help Na glucose/galactose transporter, restrict lactose and raw fruits and vegetables to decrease fecal bult) and pre and probiotics

• Infectious and secretory: treat with antibiotics

• Osmotic: disappears with fasting

How do prebiotics and probiotics exert benefits in the MNT of diarrhea?

• Replenish gut microbiota depleted by diarrhea (especially if antibiotics were used

• Increase SCFAs (decrease luminal pH = less favorable to pathogens, energy source for colonocytes, promotes water and electrolyte absorption

Discuss the evidence base for the use of probiotics.

• Still emerging

• Fermented foods are time-tested sources

• Strong evidence for certain probiotics but no recommendations yet

What are emerging connections between the gut microbiota, diet, and health?

• Good bacteria increase immunity, vitamins, and metabolism

• Bad bacteria (dysbiosis) increase obesity, inflammation, and autism

How does Covid-19 affect the GI tract?

SARS CoV-2 invades GI tract - fecal-oral transmission

Sensitivity vs specificity

• Sensitivity = say that someone has the disease if they have it

• Specific = say that they do not have it if they do not

What are polyps?

• Precursors of colon cancer

• Looks like beads

What are the risk factors of colon cancer?

• Family history

• Red or processed meats increase risk

• Whole grains and vitamins C and D decrease risk

• More common in men than women

What are the treatments for colon cancer?

Resection and ostomy

What are adenomas?

Cancerous legions

What is a stoma?

Surgical opening of intestine to outside

What is an ileostomy?

• Causes liquid stool output

• Colon, anus, and rectum are removed; stoma formed from the ileum to the outside

What is a colostomy?

• Stool output depend on location; solid stool in distal colon

• Anus and rectum removed; stoma is formed from the remaining colon to the outside

What is the MNT for ileostomy and colostomy?

• Low fiber diet initially

• Avoid problem foods: Odor: beans, cabbage, spicy food, fish; Plug up: Seeds/kernels and fibrous veggies

• Minimize odor via yogurt, cranberry juice, butter milk, and pre- and probiotic foods

• Flatulence: chew foods well, avoid drinking with straw, increase CHO foods likely to be malabsorbed and fermenred

• Adequate fluid (water is absorbed in colon the most)

• B12 supplement with distal ileum resection

What is IBD? What are the two forms?

• Chrohn's disease

• Ulcerative Colitis

• Autoimmune disease, chronic inflammation

What is the etiology of IBD? What are the potential mechanisms?

• Etiology unknown; may be a genetic link as well as environmental triggers to cause immune response and inflammation (bacteria related, smoking, alcohol)

• Mechanisms: epithelial cell barrier dysfunction, defects in innate immune system that affect commensal (good) bacteria, dysbiosis (decrease in bifidobacteria; increase in Proteobacteria), Environmental factors (diet and sanitation)

What are the common clinical features of both Crohn's disease and Colitis?

• Food intolerance

• Diarrhea and weight loss

• Fever (infection)

• Anemias (blood loss or malabsorption)

• Extra intestinal manifestations (arthritic, osteopenia, dermatologic)

Compare Crohn's and ulcerative colitis.

• Crohn's - Patches spread throughout large intestine and ileum; mucosal thickening; surgery and fistulas common; incidence increasing

• U.C. - Continuous strand from rectum, sigmoid colon, and some descending colon; mucosal thinning; incidence stable; rectal bleeding; less malnutrition

What is Crohn's ileitis?

- Inflammation of ileum causes narrowing and distended ileum
- Can result in fistula