Transcript IBS and the Low FODMAP Diet

IBS and the Low
FODMAP Diet
Najwa El-Nachef, MD
NCSGNA Conference
September 20, 2014
Irritable Bowel Syndrome
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Affects up to 20% of adults in US
Common symptoms include abdominal pain,
bloating, constipation and/or diarrhea
More frequent among females
Associated with significant decrease in quality
of life
Major economic burden on patients,
healthcare systems and community
Remains poorly understood
Horwitz et al. N Engl J Med 2001;344:1846-50
Mechanism of IBS
 Motility
 Visceral
Hypersensitivity
 Central Processing
 Genetic Factors
 Psychological factors
 Inflammation
 Gut Microflora
 Dietary Factors
Lea et al. Gastroenterol Clin North Am 2005;34:247-55
Treatment for IBS
 Focus
on reduction of symptoms
 Pharmaceuticals
 Psychological therapy
 Fiber
 Probiotics/Antibiotics
 Dietary and Lifestyle Interventions
Diet and IBS
 Relationship
between diet and
abdominal symptoms is well recognized
 From the patient’s perspective, the most
frequently perceived cause for symptoms
is food intolerance
 Up to 50% of patient’s with IBS symptoms
worsen after a meal
 60% of patients with IBS believe they have
a food allergy
Lea et al. Gastroenterol Clin North Am 2005;34:247-55
Diet and IBS
 Dairy
Free
 Low fat
 High Fiber
 No coffee/alcohol
 Food diary, self-eliminate
 Gluten free diet
Fermentable Carbohydrates
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Dietary carbohydrates can be classified into
sugars, oligosaccharides and polysaccharides
based on their degree of polymerisation.
“Fermentable” owing to their availability for
fermentation in the colon, which is either due
to the absence or reduced concentration of
suitable hydrolase enzymes for digestion or in
the case of monosaccharides because of
incomplete absorption in the small intestine.
Low FODMAP Diet
Ingested FODMAPs are poorly absorbed in
the small bowel
Small, osmotically active molecules which
draw water into the large intestine
FODMAPs are also fermented by colonic
microflora, producing hydrogen and/or
methane gas
The increase in fluid and gas leads to
diarrhea, bloating, flatulence, abdominal
pain, and distension
Low FODMAP Diet
 F:
Fermentable
 O: Oligo- saccharides
 D: Di-saccharides
 M: Mono-saccharides
 A: and
 P: Polyols
Fructose
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Simple monosaccharide
Found naturally in many fruits. Also a constituent of
sucrose and fructans.
Normally absorbed in small intestine by two
mechanisms:
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GLUT-5 transporter- present throughout small intesine.
GLUT-2 transporter- requires equal amounts of glucose
for more effective absorption.
Failure to completely absorb free fructose leads to its
delivery in the colon.
Colonic bacteria rapidly ferment free fructose to
hydrogen, carbon dioxide and short-chain fatty
acids.
Fructans
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Major source of fermentable carbohydrates
Minimal digestion due to absence of enzymes
in the human GI tract to digest the fructosylfructose glycosidic bonds
Wheat and onion are major sources
Commercial fructans dervied from sucrose or
chicory root are increasingly added to
prepared foods due to their textural and
sensory properties
Galacto-oligosaccharides
 Humans
lack a-galactosidase enzymes,
leading to the availability of GOD for
colonic fermentation
 Milk,
legumes and some grains, nuts and
seeds
Polyols
 Sugar
Alcohol
 Absorbed in small intestine by passive
diffusion
 Present in fruits and vegetables
 Commonly used in artificial sweeteners
(sorbitol, mannitol, xylitol)
 Large amounts can cause osmotic
diarrhea
Foods to eliminate
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Fructans and galactans: wheat and rye in
large amounts, onions, garlic, inulin, legumes,
lentils, artichoke, soy milk and almond milk
Lactose: milk, yogurt, ice cream, soft cheese
Excess fructose: high fructose corn syrup,
honey, agave, and various fruits (such as
apple, pear and watermelon)
Polyols: stones fruits (peach, plum, cherry),
mushroom, cauliflower and sorbitol/mannitol
Permissible Foods
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Grains: rice, oats, gluten free pasta, some gluten
free breads and cereals
Fruits: berries (except blackberries), citrus, banana,
grapes, honeydew or cantaloupe melon, kiwifruit
Vegetables: Carrots, corn, eggplant, zucchini,
peppers, green beans, lettuce, cucumber, potato,
and tomato are a few.
Meats: All meats; avoid processed meats that
contain ingredients like high fructose corn syrup,
milk solids, or onion/garlic powder
Milk: Lactose free milk, rice milk, lactose free
yogurt, hard or ripened cheeses like cheddar and
feta
What is the data?
Studies of the mechanisms underlying the
effects of fermentable carbohydrates on
gastrointestinal symptoms
Delivery of Water/Fermentable
Substrate
 Ileostomy
volunteers
 Two diets tested for 4 days each. One
high in FODMAPs and one low in
FODMAPs
 All food prepared by investigators
 At baseline and on day 4, 24 hours
effluent collected
 10 patients, ileostomy because of IBD, no
active disease
Barrett et al. Aliment Pharmacol Ther 2010 Apr;31(8):874-82
 Main
effluent weight significantly less
during LFD
 Subjects perceived significantly thicker
consistency on LFD
Barrett et al. Aliment Pharmacol Ther 2010 Apr;31(8):874-82
MRI Data with and without FODMAPs
Murray et al. Am J Gastroenterol 2014;109:110-9
MRI Data Cont’d
Studies investigating effectiveness
on IBS symptoms
Shepherd 2008
 Double
blinded, randomized placebocontrolled rechallenge trial
 25 patients responded to dietary change
 Patients were randomly challenged by
graded dose introduction of fructose,
fructans or glucose taken as drinks
 70-80% developed symptoms when
rechallenged
Shepherd. Clin Gastroenterol Hepatol 2008; 6: 765–71.
Positive Global Symptoms
Shepherd Clin Gastroenterol Hepatol 2008;6:765-771
Results for Overall Symptoms
Fructan
v.
Fructose
Mix
Overall
Pain
Bloating
Wind
Nausea
Tirednes
s
0.4589
0.0103
0.0005
0.1986
0.0974
0.0016
0.1907
0.0405
0.0005
0.0640
0.0385
0.0003
0.8476
0.5727
0.2467
0.8838
0.4217
0.0148
0.0020
0.0010
0.0078
0.0176
0.0028
0.0046
0.0003
0.0611
0.2539
0.3065
0.7651
0.3312
0.0020
0.0002
0.0003
0.0002
0.1265
0.3328
Gluocse
Fructose
v.
Mix
Glucose
Mix v.
Glucose
Low FODMAP Diet v. Standard
Dietary Advice
Symptom
Group
Improved % P value
Bloating
Standard
FODMAP
49
82
0.002
Abdominal
pain
Standard
FODMAP
61
85
0.023
Flatulence
Standard
FODMAP
50
87
0.001
Nausea
Standard
FODMAP
29
67
0.04
Composite
score
Standard
FODMAP
49
86
<0.001
Staudacher J Hum Nutr Diet 2011;5:487-95
Halmos 2014
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Crossover trial, 30 patients with IBS and 8
healthy individuals
Randomly assigned to groups that received
21 days either of diet low in FODMAPs or a
typical Australian diet
Washout period 21 day before crossing over
to the alternate diet.
Almost all food was provided during the
interventional diet periods
All stools were collected from days 17-21 and
assessed for frequency, weight, water content
Halmos et al. Gastroenterology 2014;146:67–75
“I don’t know what the heck gluten is either but I’m
avoiding it- just to be safe.”
Is Gluten the Key Player?
Supplementary Figure 1 Recruitment pathway and reasons for screen failure. Recruitment survey was a 23-item questionnaire about
symptoms, diet, and investigations for celiac disease described previously.<ce:cross-ref refid="bib20" id="crosref0245"> 20 </c...
Figure 2 Change in symptom severity from run-in for each dietary treatment over 7-day study period. Data shown represent mean ±
SEM. Differences across the treatment arms were compared by Friedman test, in which overall symptoms ( P = .001), bloating ( P ...
Biesiekiersk Gastroenterology, Volume 145, Issue 2, 2013, 320 - 328.e3
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Is FODMAP Accepted by
Patients?
FODMAP Popularity
 668,000
results on Google
 16,000“Likes”
 Several
 Many
on Facebook
Apps available
complain too restrictive
Summary
 FODMAPs
 Delivery
do not cause IBS
of dietary FODMAP to the distal
small and proximal large intestine is a
normal phenomenon, one that will
generate symptoms if the underlying
bowel response is exaggerated or
abnormal.
Summary
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Limited data, which are mainly composed of
studies with relatively small sample sizes,
support IBS symptom improvement with a lowFODMAP diet.
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Beneficial effect of a low FODMAP diet does
not appear to be predominantly based on
gluten avoidance
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No definite biomarkers as of now that are
associated with symptom response
Thank you!