sibo post gastrectomy
TRANSCRIPT
Small Intestinal Bacterial Overgrowth(SIBO)
Post Gastrectomy
Ahmed Abdelwanis
Research Fellow, Upper GI, St Jame’s University Hospital
Overview
• What is SIBO?• Factors protecting against SIBO• Associated Clinical Disorders• Pathophysiology & Clinical Picture• Testing for SIBO• SIBO & Gastrectomy• Treatment
What is SIBO?
The Gut Microflora in Healthy individuals
• There is small numbers of bacteria in the stomach and
small intestine.
• These bacteria are usually gram positive aerobes,
anaerobes are rare.
• Colonic anaerobes are not normally found in the
proximal small intestine
Small Intestinal Bacterial Overgrowth(SIBO)
Definition
The presence > 105 (colony forming units) CFU/ml
of small intestinal aspirate in the proximal small
intestine
Factors Which Protect Against SIBO
GASTRIC ACID
INTESTINAL MOTILITY
IC Valve
Pancreatic & Biliary Secretions
Mucosal Immune System
Disorders Commonly Associated with SIBO
Gastric acid secretion
Pancreatic / Biliary enzymes
Motility Disorder ImmuneDeficiency
Structural Defect
Potent acid suppressive drugs
Atrophic gastritis
Vagotomy
Chronic pancreatitis
Pancreatic insufficiency
Cirrhosis
Aging
Celiac sprue
Cirrhosis
Crohn’s disease
DM
Pseudo-obstruction
Renal failure
Radiation enteritis
Scleroderma
Immuno- suppressive Rx
CVID
IgA deficiency
Fistula
IC valve resection
Bariatric surgery
Gastrectomy
Small bowel div.
Surgical blind loop
Pathophysiology & Clinical Picture
SIBOSIBO
Glycosidase &Protease
• (-) disaccharidase enzyme• Bile Inactivation• inflammatory cytokines• Intestinal Permeability
(leaky gut)
CHO malabsorption
CHO malabsorption
Steatorrhea/ Vit Def
Steatorrhea/ Vit Def
Systemic Sx’sSystemic Sx’s
Hydrogen/Methane/CO2/H2S
Hydrogen/Methane/CO2/H2S
Fermintation Fermintation
Bloating\FlatulenceDiarrhea\Constipation
Abdominal Pain
Damage The Brush Border
Clinical Picture• Abdominal pain, including cramping
• Constipation (methane)
• Diarrhea (hydrogen)
• Excessive flatulence
• Malabsorption problems, i.e. fat soluble vitamins, vitamin B12, iron
• Systemic complaints such as fatigue, body pain, joint pain, headaches
Testing for SIBO
Culture of Jejunal Aspirate
Gold Standard This however, is not an ideal method of diagnosis:
•Costly and invasive method•High rate of false negative results•Technical problem•Risk of oral contamination
Hydrogen Breath Test (HBT)
Bacterial Concentration,Organisms/mL
<102
>105
Methods of Detection
Direct Aspiration and Culture
Glucose Breath Test
Lactulose Breath Test
Glucose
Lactulose
HBT
HBT Interpretation
• The exhaled gas is measured in parts per million (ppm)
• The fasting baseline of expired hydrogen should be <10ppm (ideally <5ppm)
• majority of studies suggest that a hydrogen peak exceeding 10-20 ppm above baseline is indicative of a positive glucose test
HBT Drawbacks
• Glucose is absorbed completely in proximal small intestine
• Time consuming procedure (especially in slow transit)
• Methane/H2S producing Bacteria
• +ve HBT may not always mean that a patient's symptoms are caused by SIBO
SIBO & Gastrectomy
Stomach FunctionsReservoir
Mixes &GrindsControls gastric emptying
Destroys ingested bacteria
Secretes digestive juices
Nutritional consequences after gastrectomy
• Dumping Syndrome (Early & Late)
• Vitamin B12 deficiency
• Iron Deficiency Anaemia
• Calcium deficiency
Significance of SIBO in post-gastrectomy patients
• SIBO is expected in post-gastrectomy patients however
its role has not been clarified
• Studies are trying to identify prevalence, symptoms and
Malnutrition and their relation to SIBO
Paik et al 2011• Paik et al examined a total of 76 patients for
bacterial overgrowth postgastrectomy• 59 SIBO +ve & 17 SIBO –ve• SIBO appears to be a cause of postprandial
intestinal symptoms. Moreover, SIBO positive postgastrectomy patients might have a risk for late hypoglycaemia
• There were no differences regarding age, gender, the time interval from operation, type of operation, and the presence or type of dumping syndrome
It is clear that future studies are needed to
fully understand the role of SIBO in
postgastrectomy patients by demonstrating
the response to antibiotic treatment of SIBO
Treatment• Correct predisposing condition if possible
• Correct Nutritional Deficiencies
• Diet Management
• Antibiotics • Probiotics
Diet
Antibiotics
There exists no consensus on the most efficacious dose or duration of
treatment
Antibiotics
• Empiric
because the contaminating bacterial populations are quite numerous, choice of antibiotic remains primarily empiric
• Meta-analysis by Shah et al 2013
Antibiotics appear to be more effective than placebo for breath test normalisation in patients with symptoms attributable to SIBO, and breath test normalisation may correlate with clinical response
Antibiotics
1) Amoxicillin-clavulinic acid (30 mg/kg/day)
2) Metronidazole (20 mg/kg/day) + cephalosporin
(30mg/kg/day)
3) Norfloxacin (800 mg/day)
4) Doxycyclin (200 mg/day)
5) Rifaximin (1650 mg/per day)
• The antibiotic Rifaximin is poorly absorbed
• In a randomized controlled trial, 142 patients with SIBO were randomized to seven days of rifaximin (1200 mg/day) or metronidazole (750 mg/day), glucose breath test normalization rates at one month were significantly higher in patients treated with rifaximin compared with metronidazole
Rifaximin
Probiotics• One pilot study assessed the effect of Lactobacillus casei
on SIBO patients, Following the 6-week intervention, 64% of patients no longer had a positive breath test, but there was no significant improvement in abdominal symptoms
• In another pilot study, patients were randomised to receive either a probiotic or metronidazole. A statistically significant difference in symptomatic response favoured the use of the probiotic over the antibiotic
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