git j club sibo 16
TRANSCRIPT
Kurdistan Board GEH/GIT Surgery Weekly J ClubSupervised by Prof Dr.Mohamed Alshekhani.
MBChB-CABM-FRCP-EBGH.
Background: GI symptoms are commonly seen in PC, 15.9 million visits /year. One of these syndromes, (SIBO), is a diagnosis often entertained in
pc& gastroenterology settings. A dysbiosis syndrome is most often referred to as SIBO ,less as
blind loop or stagnant loop syndrome. The syndrome first described by Faber in 1897 when he described
a case of “blind loop syndrome” in a patient with underlying intestinal strictures.
Prevalence stimates from 0-15.6% in healthy individuals, with increasing prevalence with age & medical comorbidities.4
It is often considered in the DD owing to its nonspecific presentation.
Background: SIBO can be broadly defined as excessive bacteria in
the SI,an increase in the number of bacteria in the small bowel to >105 CFU/mL, some 103 CFU/mL.
The clinical implications& even the diagnostic criteria themselves, have been debated recently.
Etiology: There does not seem to be a single unifying underlying etiology. Abnormalities in anatomy, motility, pH,immunity are all contributors
allowing for local proliferation of coliform bacteria or penetration of oral-type bacteria.
This dysbiosis is characterized by colonic-type bacteria that ferment carbohydrates, leading to gas production.
Anato risks can be intrinsic, traumatic, or iatrogenic. Intrinsic anatomical risk factors of SI include obstruction, diverticula fi
stulas. Individuals with H/O abdominal surgical intervention can be at
increased risk due to either intentional alteration in existing anatomy (ie, Roux-en-Y) or postop complications, including strictures adhesions, lead to dysmotility&independently increase the risk.
Etiology: Primary dysmotility can be seen, but secondary dysmotility is much more
common. Secondary dysmotility can be a consequence of systemic disease,
irradiation, or medication use. systemic diseases known to alter motility & associated with SIBO include
Parkinson disease, systemic sclerosis, hypothyroidism,diabetes mellitus. The increasing incidence of SIBO with age is also likely secondary to
changes in intestinal motility, alchlorhydria &polypharmacy. Medications: Narcotics by effects on GI motility,PPI; effect on gastric pH barrier. Outside classic RFs; cirrhosis, celiac, morbid obesity, pancreatitis, ?IBS.
Clinical features: Often, SIBO is entertained in the DD due to the variety of people at
risk &its non-specific presentation. The classic presentation: steatorrhea, abdominal bloating&weight
loss, but this is an infrequent. More commonly, report bloating, flatulence, abd pain& diarrhea. In more severe cases, patients can experience malabsorption
leading to weight loss&malnutrition. Patients with severe symptoms are at risk for a variety of defi
ciencies, mostly vits A, D, E, B12& iron, leading to either macrocytic or microcytic anemia, polyneuropathy&metabolic bone disease.
Vitamin K is usually unaffected because it is a by-product of bacterial metabolism.
Diagnosis: Because of NS symptoma & broad DD ,effective clinical
tests are essential to the diagnosis of SIBO. Several testing options have been extensively studied,
including therapeutic trials of antibiotics, SB aspiration / culture& breath testing, all of which have strengths & weaknesses.
Diagnosis:antibiotics A method often used is a therapeutic trial of antibiotics due to the
potential for both diagnostic&therapeutic benefits,but if patients do not respond, the diagnosis has not been ruled out.
Risks: Antibacterial stewardship, unwanted adverse effects, antibiotic
resistance&C difficile colitis. No criteria to define a response to therapy, especially in patients
who have other comorbidities as IBS & patients may have improvement,due to the effect on colonic rather than small-bowel fermentation.
This approach can be used after discussing these issues with the patient.
Diagnosis:Breath testing The most widely available, least expensive. They detect the presence of methane/hydrogen, the human body is
unable to produce. Lactulose/glucose solutions are used as carbohydrate substrates. Before testing, patients must be off antibiotics for 2 weeks, avoid high-
fiber foods (ie, vegetables /coarse breads) the day before&fast 12 hours before.
Results can be variable owing to a variety of host factors, such as the types and proportions of colonizing bacteria, residual carbohydrates,the absorptive capacity of the gut, age & sex.
The sensitivities/specificities; 31-77% &44-100%, respectively, leading to high false-positive rates.
Glucose breath testing endorsed but more data needed
Diagnosis:SB Culture The most widely accepted test of choice Most aspirates are obtained from the duodenum during upper endoscopy. Quantification of bacterial growth from SB aspirate is currently the most
widely accepted. even this test has limitations: Invasiveness of the upper endoscopy, time consumption, need for
sedation,cost. Most accept a threshold of bacterial growth >105 CFU/mL, but some 103
CFU/mL. Technical limitations, including esop/ oral bacterial contamination, leading
to false-positives, the inability of the scope to reach the distal small bowel, leading to false-
negatives.
Management: Antibiotics are the hallmark therapy. Antibioticsshown to be superior to placebo in resolution of SIBO measured
by normalization of BTs. the most common; ciprofloxacin, metronidazole, neomycin,
rifaximin,tracycline. The overall rate of breath test normalization with antibiotics was 50% vs
10% for placebo. Rfaximin, had similar efficacy compared with ciprofloxacin&metronidazole. Rifaximin may be preferable due to its intrinsic lack of systemic
bioavailability, but the cost of can be limiting. Commonly used regimens include ciprofloxacin 250 mg orally twice daily
for 7 days, metronidazole 250 mg orally twice daily for 7 days&rifaximin 550 mg orally twice daily for 7 days.
Management: In patients who have contraindications to antibiotics or who
prefer to avoid antibiotics. Use of elemental diet, which includes only nutrients
absorbed in the proximal small bowel, shown to lead to breath test normalization & improvement in symptoms in a large proportion of patients.
Widespread use of elemental diets is unlikely given the amount of restriction required.
The evidence for probiotics is inconclusive at best Herbal &homeopathic regimens; there is a lack of evidence
to support a specific regimen.
Management: SIBO is often a relapsing condition given it is a secondary
process. A variety of predisposing factors lead to the development
of SIBO. Alteration of these factors is preferable (ie, removal of intra-
abdominal adhesions), but most often is not possible. Recurrent infections can be treated with a repeated
antibiotic course or with alternating antibiotic regimens. Prokinetics promising to prevent recurrence, but more data
are needed.
Small Bowel Bacterial Overgrowth (SBBO or SIBO)
Bacteria and the gutDefinitionSymptomsCauses and conditions
Hydrogen Breath TestingQuinTron: www.quintron-usa.com
Measures both hydrogen and methane Mail-in kit option
MicroDirect: www.breathh2.com Measures hydrogen only Web site offers info on billing, coding,
reimbursementGI Pathology: offers mail-in kit
Testing Instructions No antibiotics for at least 7 days NPO for 12 hours before test NPO during test except for substrate in 6-8
ounces of water Avoid eating slowly digesting foods the day
before No smoking 30 min. before or during test No sleeping 30 min. before or during test
Testing Instructions
Baseline breath sampleSubstrate (lactulose 10 grams) mixed in
6-8 ounces of water.Additional breath samples taken at 20
minute intervals for at least 5 additional samples.
Interpreting ResultsLook for bi-phasic peaks in true
positivesEarly increase of at least 12 ppm Investigate interferences to accurate
results: Smoking, laxative use, last meal, antibiotic
use, previous surgeries, COPD