Prebiotics, Probiotics,

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Prebiotics, Probiotics, Antibiotics
Controversies in the Treatment of IBS

• Brian E. Lacy, Ph.D., M.D.
• Associate Professor of Medicine
• Dartmouth Medical School
• Director, GI Motility Laboratory
• Dartmouth-Hitchcock Medical Center

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Disclosure

• Investigator Initiated Research Support
  AstraZeneca, GlaxoSmithKline, Medtronics,
  Novartis, Prometheus
• Speakers Bureau Novartis, Takeda

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Goals

• Define commonly used terms
• Review the microecology of the intestinal tract
• Discuss the mechanism of action of probiotics
• Review the available literature on probiotics and
  IBS
• Assess the role of antibiotics in the treatment
  of IBS

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Functional Foods

• Functional foods substances or supplements
  administered to obtain a specific result
• Also called nutriceuticals or biotherapeutics
• Examples
• Prebiotics
• Probiotics

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Prebiotics

• Non-digestible food supplements or ingredients
• Not absorbed or degraded
• Alter the balance of intestinal flora and by
  acting as substrates stimulate the growth of
  beneficial bacteria (i.e., Lactobacillus and
  Bifidobacteria)

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Prebiotics

• Fructooligosaccharide (aka oligofructose)
• Isomaltooligosaccharide
• Xylooligosaccharide
• Inulin
• Fiber
• Oligomate
• Palatinose
• Pyrodextrin
• Raftiline

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Probiotics

• Non-pathogenic live microbial food supplements
• Organisms that, when administered in adequate
  amounts, exert a positive influence on the health
  of the host animal
• Live organisms that benefit the host animal by
  improving intestinal microbial balance
• Usually administered in yogurt or capsules

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A Brief History of Probiotics

• Metchnikoff 1907 ingesting yogurt with
  Lactobacilli reduces toxic bacteria of the gut
  and prolongs life
• Kipeloff 1926 stressed importance of
  Lactobacillus acidophilus for good health
• Rettger 1930s early clinical application of
  Lactobacillus
• Parker 1974 1st to use the term probiotics
• Fuller 1989 defined probiotics

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Probiotics

• Lactobacilli anerobic, gram () rods
• casei
• plantarum
• acidophilus
• reuteri
• Bifidobacteria anerobic, gram () rods
• VSL 3 (8 separate organisms 3 Bifidobacteria, 1
  Streptococcus, 4 Lactobacilli)
• Enterococcus
• Streptococcus salivarius
• Saccharomyces

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How is normal mucosal immune function maintained?

• GI secretions (saliva, acid, bile)
• Mucus
• Normal peristalsis (presence of MMC)
• Barrier function (tight junctions)
• Intestinal proteolysis
• Intestinal immune cells
• IgA production and secretion

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Intestinal Microecology
Foods that enter the GI Tract
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Intestinal Flora A symbiotic relationship with
the host

• Human GI tract contains 10x more bacteria (1014)
  than eukaryotic cells in the body
• Protects the host
• Stimulates immune function
• Produces antimicrobial substances
• Trophic effect on intestinal epithelium
• Maintains the enterohepatic circulation of bile
  acids
• Involved in metabolic processes (i.e.,
  fermentation) in the colon

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Intestinal Microflora Location Prevalence

• Rare in the esophagus
• Uncommon in the stomach
• primarily gram ()
• 102 - 104
• 105 in the jejunum primarily aerobes
• 1010 1012 in the colon
• primarily anerobes
• 1000x more anerobes than aerobes

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Formation Maintenance of Gut Flora (Microbiota)

• Genetic factors
• Age
• Gender
• Mothers microbiology
• Mode of delivery
• Feeding practices
• Breast-fed Bifidobacterium
• Bottle-fed - Lactobacillus
• Co-morbid conditions
• Medications
• Diet

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Predominant human fecal flora

• Aerobic organisms
• E. coli
• Enterococcus sp.
• Streptococcus sp.
• Bacillus sp.
• Citrobacter sp.
• Klebsiella sp.

• Anaerobic species
• Anaerobic cocci
• Bacteroides sp.
• Eubacterium sp.
• Bifidobacterium sp.
• Lactobacillus sp.
• Fusobacterium sp.
• Clostridium sp.

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Conditions that can disrupt normal gut flora
homeostasis

• Medications
• Antibiotics
• Surgery
• Radiation
• Diet
• Co-morbid diseases
• Crohns
• Scleroderma

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Probiotics An Overview

• Key properties
• Mechanisms of action
• Potential uses

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Key Properties of Probiotics

• Bacteria of human origin
• Safe to use in large amounts in clinical practice
• Resist secretions of the upper GI tract
• Survive passage through the GI tract
• Adhere to human intestinal cells

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Key Properties of Probiotics

• Able to colonize the lumen of the GI tract
• Help to protect the cells against invasion by
  pathogens
• Produce antimicrobial substances
• hydrogen peroxide
• organic acids
• bacteriocins
• Antagonize carcinogenic and pathogenic flora

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Probiotics Mechanism of Action

• Competitive inhibition
• Barrier protection
• Immune effects
• Anti-inflammatory effects
• Production of various substances (enzymes, SCFA,
  bacteriocidal agents)
• Ability to alter local pH and physiology
• Provides nutrition to colonocytes

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Probiotics Competitive Inhibition

• Helps to restore the balance of good bacteria
  and bad bacteria
• Facilitates the growth of healthy bacteria
  i.e., Bifidobacterium and Lactobacillus
• Bifidobacterium infantis inhibits the growth of
  Salmonella (OMahony 2004 Gastro)

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Probiotics Barrier Protection

• Intestinal permeability to bacteria is increased
  with inflammation, i.e., Crohns, UC,
  ischemia (Nejdfors et al Scan J Gastroenterol
  1998)
• Pretreatment with L. plantarum 299v inhibits E.
  coli intestinal permeability (Mangell et al
  Dig Dis Sci 2002)
• B. infantis prevents bacterial (Salmonella)
  translocation (OMahony Gastro 2004)

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Probiotics Immune Function

• Mononuclear cells incubated with Lactobacilli
  produce higher levels of IFN-gamma, TNF-alpha,
  and IL-1 (MacFarlane Cummings, BMJ, 1999)
• Bifidobacteria suppressed the pro-inflammatory
  mediators (TNF-alpha, IFN-gamma, IL-12) in a
  murine model of IBD (IL-10 knockout)
  (McCarthy et al, Gut 2003)
• In healthy volunteers, L. rhamnosus increased
  phagocytic activity and NK tumor cell killing
  activity (Sheih et al, J Am Coll Nutri 2001)

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Probiotics Immune Function

• Borruel and colleagues assayed ileal specimens
  from Crohns patients (10) and compared to 5
  controls (right hemicolectomy for colon cancer)
• Specimens cultured with various bacteria (L.
  casei, L. bulgaricus, L. crispatus)
• CD4 levels and TNF-alpha levels reduced in
  Crohns explants but not in normal volunteers
• Impression probiotics interact with
  immunocompetent cells to modulate the production
  of pro-inflammatory cytokines from ileal tissue
  in Crohns patients (Borruel Gut 2002)

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Probiotics Production of Other Substances

• Intestinal bacteria play a key role in the
  production of short-chain fatty acids (SCFA)
• Butyric acid is the main fuel for colonocytes
• L. plantarum appeared to increase production of
  butyric acid in 36 healthy volunteers, leading to
  reductions in fibrinogen, leptin, and monocyte
  adhesive properties
• (Naruszewicz et al Am J Clin Nutr 2002)

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Probiotics Impact on Local Physiology

• Example - Antibiotic associated diarrhea
• Restores resident flora
• Increases production of SCFA
• SFCAs are absorbed by diffusion, leading to
  increased water and Na absorption
• Stimulates colonocyte proliferation, which may
  further improve water and Na reabsorption

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Probiotics Potential Uses

• IBS
• IBD
• Infectious diarrhea in children (i.e., rotavirus)
• Travelers diarrhea
• Antibiotic associated diarrhea
• Clostridium difficile

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Genetic Predisposition
Stress
Environmental Influences
History Of Abuse
Parental Modeling
Development Of IBS
Infection/ Inflammation/ SIBO
Other Factors
Anxiety
Stress
Somatization
Poor Coping Skills
Depression
Manifestation Of IBS symptoms
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Pathogenesis of IBS Stress

• Animals models of stress demonstrate loosening of
  intercellular tight junctions
• Stress is associated with increased rate of
  post-infectious IBS
• Stress is associated with increased frequency and
  intensity of symptoms, and increased consulting
  behavior (Drossman et al, 2005)

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Pathogenesis of IBS Infections

• Chaudary Truelove 1962 described onset of
  IBS after dysentery
• McKendall Read 1994 Bowel dysfunction
  developed in 12/38 patients after salmonella
  infection
• Neal et al (1997) at 6 month follow-up, 7 of
  patients developed IBS symptoms after bacterial
  gastroenteritis
• Garcia-Rodriguez (1999) RR for developing IBS
  symptoms after bacterial gastroenteritis 10

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Pathogenesis of IBS Infections

• Gwee (1999)
• 94 patients with acute gastroenteritis compared
  to controls
• 23 had IBS symptoms at 3 months
• 64 were women
• Stress, hypochondriasis associated with increased
  likelihood
• Rectal biopsies at 3 months revealed an increased
  number of mucosal inflammatory cells

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Pathogenesis of IBS Inflammation

• Gwee et al (Gut 1999) rectal biopsies revealed
  an increase in mucosal inflammatory cells in
  patients with post-infectious IBS
• Spiller et al (Gut 2000) After Campylobacter
  enteritis patients (n21) were found to have
  increased
• mucosal permeability
• number of lymphocytes in the lamina propria
• number of intra-epithelial lymphocytes at 1 year
  FU

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Pathogenesis of IBS Inflammation

• Tornblom et al (Gastro. 2002) Full thickness
  jejunal biopsies of IBS patients (n10) revealed
  low-grade infiltration of lymphocytes in the
  myenteric plexus in 9 patients, and neuronal
  degeneration in the myenteric plexus in 6/9
  patients
• Experimental colitis alters myenteric nerve
  function and previous inflammation
  changes/sensitizes rats to stress
  (Jacobson et al, Gastro 1995 Collins et al,
  Gastro 1996)

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Pathogenesis of IBS Altered Gut Flora

• IBS patients may have different ratios of normal
  gut flora
• Reduced levels of Lactobacilli and
  Bifidobacterium
• Increased levels of Clostridium
• Balsari et al, Microbiologica 1982
• Malinen et al, Am J Gastro 2005
• Lin, JAMA 2004

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Risk Factors for SIBO

• Ileocecal resection
• Small intestinal stasis
• Diverticulosis, strictures
• Abnormal motility (scleroderma, CIP)
• Hypochlorhydria
• Immunodeficiency
• Gastroparesis
• Chronic diseases (cirrhosis, alcoholism, celiac)
• Pancreatitis, Parkinsons disease
• ?? IBS

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Pathogenesis of IBS SIBO

• 78 of patients (157/202) referred for LHBT had
  bacterial overgrowth (Pimental et al, 2000)
• 84 of 111 IBS patients (Rome I criteria) had
  SIBO (Pimental et al, 2003)
• 65 of IBS patients have SIBO (Nucera et al, APT,
  2005)

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Pathogenesis of IBS SIBO

• Walters Vanner 10 of IBS Pts (Am J
  Gastroenterol 2005)
• Crowell et al 10 (ACG 2005)
• Olden et al 10 (ACG 2005)
• Jones et al 10 (ACG 2005)
• Ruff et al 6 of IBS patients had SIBO, using
  duodenal aspirates (ACG 2006)

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Probiotics IBS

• Halpern et al (Am J Gastroenterol 1996)
• L. acidophilus (Lacteol Fort)
• Dose 5 x 109 q day (heat killed)
• Route capsule
• Study randomized, double-blinded, cross-over
• Subjects entered 18
• Criteria IBS symptoms
• 6 weeks self-administered questionnaire
• Mean daily scores were better on Lactobacillus
  compared to placebo in 9 patients who responded

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Probiotics IBS

• OSullivan et al (Dig Liver Dis 2000)
• Lactobacillus GG casei
• Dose - 1 x 1010 daily
• Route - tablet
• Randomized, double-blinded, placebo-controlled
• 24 Subjects entered 19 completed
• Rome II criteria
• 20 weeks
• No significant benefits noted (? some relief of
  bloating)

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Probiotics IBS

• Sen et al (Dig Dis Sci 2002)
• Lactobacillus plantarum 2990
• Dose - 6.5 x 109 daily (Pro Viva fruit drink)
• Route oral (approx. 125 cc)
• Double-blinded, PC, crossover study
• 12 subjects entered
• Rome criteria 4 weeks
• No improvement in symptoms
• Decrease in breath H2 by LBT

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Probiotics IBS

• Niedzielin et al (Eur J Gastro Hepatol 2001)
• Lactobacillus plantarum 299V
• Dose - 1 x 1010 twice daily (Pro Viva)
• Route liquid (approx. 250 cc)
• Randomized, double-blinded, PC
• 40 subjects total
• Rome criteria 4 weeks
• Decreased symptoms with some improvement in
  abdominal pain compared to baseline in the L.
  plantarum group (p lt 0.05)

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Probiotics IBS

• Nobaek et al (Am J Gastroenterol 2000)
• Lactobacillus plantarum D5M9843
• Dose - 2 x 1010 daily
• Route drink (approx. 400 cc)
• Randomized, double-blinded, placebo-controlled
• 60 subjects entered 52 completed
• Rome criteria 4 weeks
• Decrease in flatulence and abdominal discomfort
  (NS)
• Bacteria recovered from the stool

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Probiotics IBS

• Kim et al (APT 2003)
• VSL 3
• Dose 4.5 x 1011 daily
• Route powder
• 25 IBS subjects entered 24 completed
• Parallel group, DB, placebo-controlled
• Rome criteria diarrhea predominant
• 2 week run-in 8 week trial
• Less bloating noted (p 0.09) other Sx not
  improved
• No change in GI transit time

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Probiotics IBS

• Saggioro et al (J Clin Gastro 2004)
• Lactobacillus plantarum bifidobacteria vs.
  Lactobacillus plantarum Lactobacillus
  acidophilus vs. placebo
• Dose 5 x 109 cfu for each agent
• Route - oral
• Randomized, ? DB, PC
• 70 subjects entered and completed mean age 40
• Rome II criteria
• 4 weeks
• Pain severity decreased by 20 in both groups
  compared to placebo (no statistics performed)

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Probiotics IBS

• OMahony et al (Gastroenterology 2005)
• Lactobacillus salivarius UCC4331 1 x 1010
• Bifidobacterium infantis 35624 1 x 1010
• Route oral malted milk drink
• Randomized, double-blinded, PC
• 75 subjects entered, 68 eligible for analysis
  mean age 44 1/3 men and 2/3 women
• Rome II criteria all subtypes included
• 8 weeks
• Sx, Qol, stool microbiologic studies, IL-10 and
  IL-12 serum levels

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Probiotics IBS

• OMahony et al, cont.
• B. infantis improved global symptom scores and
  individual scores (pain/discomfort,
  bloating/distention, difficult defecation)
  significantly more than both Lactobacillus and
  placebo
• B. infantis improved QoL score for only domain of
  health worry
• B. infantis normalized IL-10/IL-12 ratios
• No change in stool frequency or consistency

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Probiotics IBS

• Whorwell et al (Am J Gastro 2006)
• Bifidobacterium infantis 35624
• Dose 106, 108, 1010 cfu daily x 4 weeks
• Route freeze-dried, encapsulated
• Randomized, double-blinded, PC multi-center
• Rome II criteria all subtypes (55 D 21 C)
• 362 female IBS patients (approx. 90 per group)
  330 completed the study 293 analyzed
• Primary endpoint abdominal pain score (6 point
  Likert scale) global IBS symptoms

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Probiotics IBS

• Whorwell et al continued
• B. infantis at 108 cfu/day was significantly
  superior to placebo and to other B. infantis
  doses (p 0.023) at improving abdominal pain as
  well as general composite scores (bloating,
  incomplete evacuation, straining, bowel
  dysfunction p lt 0.02)

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Probiotics IBS Problems

• In general, small studies
• Underpowered
• Most do not verify bacterial transit survival
• Varying doses
• Varying strains/species/subspecies
• Varying compositions
• Varying endpoints

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Probiotics Questions to answer

• Which species is best?
• Are combination agents better?
• What is the appropriate dose?
• What is the appropriate duration of treatment?
• What outcome measures are appropriate?
• What is the appropriate follow-up?
• What is the appropriate patient population?

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Probiotics Whats needed

• Standardized protocols
• Larger studies
• Defined outcomes
• Correlation with symptoms? Or cytokine levels? Or
  rectal biopsies? Or

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Antibiotics and IBS
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IBS Cured by AntibioticsAntibiotics Cure
IBS SymptomsIBS Symptoms Improve on
Antibiotics
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IBS SIBO

• Pimental et al Am J 2000
• 202 Pts underwent LBT and retrospectively
  diagnosed with IBS 157 (78)
• 47 patients treated with antibiotics returned
  (70 dropout rate) (neomycin, metronidazole,
  ciprofloxacin, doxycycline, and unknown 36)
• 7-10 days later repeat LHBT and FU questionnaire
• 12/25 (48) who had complete eradication no
  longer met Rome I criteria for IBS
• 22/47 incomplete eradication (47) and 13/25
  had eradication but still met Rome I criteria

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IBS SIBO

• Pimental et al - Am J Gastro 2003
• 111 IBS patients (Rome I 37 C 44 D)
• All had LHBT
• Randomized to neomycin (500 mg BID) or placebo
• At 7 day FU, 8/41 (19.5) treated with neomycin
  normalized LHBT
• ITT analysis neomycin improved composite score
  35 compared to placebo 11.4 (P lt 0.05)

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IBS Bloating

• Shahara et al (Am J Gastro 2006)
• 124 patients with bloating excessive flatulence
• 56 met Rome II criteria for IBS (20 D, 38 C)
• Mean age approx.40 55 women
• Lactulose breath test (-) in all patients
• Rifaximin (400 mg bid n 63) vs. placebo x 10
  days
• Rifaximin treated patients had a reduction in gas
  and bloating immediately following treatment
  (37.5 vs. 20.4, plt0.04) and at 10 day follow-up
  (28.6 vs. 11.5 p 0.02)

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IBS SIBO

• Pimental et al (Ann Int Med 2006)
• 87 IBS patients (Rome II) aged 18-65
• Mean age 39 29 M 58 W
• Randomized, DB, PC
• Rifaximin 400 mg tid vs. placebo
• LBT performed but not reported
• Composite scores used

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IBS SIBO

• Pimental 2006, contd
• At 10 week follow-up, overall symptoms improved
  (38.6 vs. 23.4 p lt 0.05), but no improvement
  in bowel habits, abdominal pain
• Some improvement in bloating also noted (p
  0.010)

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Summary

• Confusing
• Conflicting
• Contradictory

• Stimulating
• Challenging
• Exciting

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Pathogenesis of IBS

• Genetic factors
• Stress
• Infections
• Inflammation
• Diet
• Small intestine bacterial overgrowth

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Probiotics and Immune Function

• Probiotics have been shown to induce TNF activity
  in a murine model of NAFLD (Li et al,
  Hepatology, 2003)
• In healthy volunteers, L. rhamnosus increased
  phagocytic activity and NK tumor cell killing
  activity (Sheih et al, J Am Coll Nutri 2001)

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What is the role of genetics in IBS?

• Familial aggregation studies
• Twin studies
• Genetic epidemiology studies
• Reduced IL-10-levels
• Alteration in SERT

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Evidence of heredity in IBS Twin studies
0

FBD Functional Bowel Disorder
Morris-Yates A, et al. Am J Gastroenterol.
199893(8)13117 Levy RL, et al.
Gastroenterology. 2001121(4)799804 Lembo A, et
al. Gastroenterology. 2002120A636 Mohammed I,
et al. Am J Gastroenterol. 2005100(6)13404
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Mechanisms in IBS
External influences Emotions
EnhancedPerception
Vagal Nuclei
5-HT
Sympathetic
AlteredMotility
VisceralHypersensitivity
Adapted from Camilleri and Choi. Aliment
Pharmacol Ther. 1997113.
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Functions of the Gut Wall

• Mechanical barrier
• Absorption and secretion
• Key component of normal immune function
• Immune cells
• Antibody production

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GI Secretions

• GI tract is exposed to 6 8 liters/day
• Bile acids can inhibit indigenous flora
• Gut flora maintains enterohepatic circulation of
  bile acids by deconjugation and transformation