Tag Archives: SIBO

Small Intestinal Bacterial Overgrowth (SIBO) A Gut Related Diagnosis That Is Under Diagnosed

What is SIBO?

Simply put, Small Intestine Bacterial Overgrowth is a chronic bacterial infection of the small intestine.  The infection is of bacteria that normally live in the gastrointestinal tract but have abnormally overgrown in a location not meant for so many bacteria.  (1)

The Problem
The bacteria interfere with our normal digestion and absorption of food and are associated with damage to the lining or membrane of the SI (leaky gut syndrome, which I prefer to call leaky SI in this case).

  • They consume some of our food which over time leads to deficiencies in their favorite nutrients such as iron and B12, causing anemia.
  • They consume food unable to be absorbed due to SI lining damage, which creates more bacterial overgrowth (a vicious cycle).
  • After eating our food, they produce gas/ expel flatus, within our SI.  The gas causes abdominal bloating, abdominal pain, constipation, diarrhea or both (the symptoms of IBS).  Excess gas can also cause belching and flatulence.
  • They decrease proper fat absorption by deconjugating bile leading to deficiencies of vitamins A & D and fatty stools.
  • Through the damaged lining, larger food particles not able to be fully digested, enter into the body which the immune system reacts to.  This causes food allergies/ sensitivities.
  • Bacteria themselves can also enter the body/bloodstream.  Immune system reaction to bacteria and their cell walls (endotoxin) causes chronic fatigue and body pain and burdens the liver.
  • Finally, the bacteria excrete acids which in high amounts can cause neurological and cognitive symptoms.

Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO. (2)

The overall prevalence of SIBO in the general public is unknown. In general, SIBO is substantially underdiagnosed. There are several reasons for this fact. Some patients may not seek healthcare or SIBO may not be properly diagnosed by medical investigations. SIBO might be asymptomatic or with non-specific symptoms only, and last but not least, all symptoms might be incorrectly ascribed to the underlying disease (leading to SIBO). Of course, diagnostic yield also depends on the methods used for investigation. According to different studies with the investigation of small sets of clinically healthy people as a control, findings consistent with SIBO were found in 2.5% to 22%. (2)

In particular diseases and disorders, literature data on prevalence differ substantially. For instance, the prevalence of SIBO in patients fulfilling diagnostic criteria for irritable bowel syndrome was 30%-85%[911,16,18,19]. The prevalence of SIBO in coeliac disease non-responding to a gluten-free diet was up to 50%[20]. In liver cirrhosis, SIBO was diagnosed in more than 50% of cases[21,22]. In a small group of elderly people (70 to 94 years old) with lactose malabsorption, SIBO was documented in 90%[23]. An interesting study was performed on asymptomatic morbidly obese subjects and SIBO was found in 17% (compared to 2.5% in non-obese persons

Diagnostic Testing:

Unfortunately there is no perfect test.  The small intestine (SI) is a hard place to get to.  If we want to see or sample the SI, endoscopy only reaches into the top portion, and colonoscopy only reaches into the end portion.   The middle portion, which is substantial (about 17 feet) is not accessible, other than by surgery.  And stool testing predominantly reflects the large intestine (LI).  Luckily, there is a non-invasive test which is commonly used in SIBO research; the Hydrogen Breath Test. (1)

Hydrogen Breath Test

A hydrogen breath test can be used to diagnose several conditions:  H pylori infection, carbohydrate malabsorption (ex. lactose) and SIBO.

SIBO Breath Test
Breath testing measures the hydrogen (H) & methane (M) gas produced by bacteria in the SI that has diffused into the blood, then lungs, for expiration.  H & M are gases produced by bacteria, not by humans.  The gas is graphed over the SI transit time of 2 or 3 hours & compared to baseline.  Patients drink a sugar solution of glucose or lactulose after a 1 or 2 day preparatory diet.  The diet removes much of the food that would feed the bacteria, allowing for a clear reaction to the sugar drink.
Two types of tests may be used: Lactulose or Glucose.

Lactulose Breath Test (LBT)

Humans can’t digest or absorb lactulose.  Only bacteria have the proper enzymes to do this.  After they consume lactulose, they make gas.  If there is an overgrowth, this will be reflected in the levels of H and/or M.

The advantage to this test is that it can diagnose overgrowth in the distal end of the SI, thought to be more common.  The disadvantage is that it cannot diagnose bacterial overgrowth as well as the Glucose Breath Test (GBT).

Glucose Breath Test (GBT)

Both humans and bacteria absorb glucose.  Glucose is absorbed within the first three feet of the SI, therefore if the bacterial gases of H and/or M are produced during this test, it reflects an overgrowth in the proximal/upper end of the SI (within the first two feet).

The advantage to this test is that it successfully and accurately diagnoses proximal overgrowth.  The disadvantage is that it cannot diagnose distal overgrowth, occurring in the latter 17 feet of the SI, which is thought to be more common.

How is the test performed?

The test is performed either at home with a take home kit or at a facility that has a breath testing machine such as a hospital, doctors office, or clinic lab.  It takes 1-3 hours in the morning after a 12 hour fast the night before and a special diet the day before.  At home kits may be obtained from numerous breath testing laboratories.  Lactulose kits require a physician prescription.

Which Test Is Best?

Physicians and studies use both glucose and lactulose.  I currently use the 3 hour lactulose test and have good results with this method.

Test Interpretation

Doctors vary widely in how they interpret SIBO breath tests.  What one physician calls negative, another call positive. There is no universally accepted standard among physicians at present.
For a detailed explanation of various positive standards and interpretation with case examples, please see my article on test interpretation or either one of my SIBO class videos.

SIBO: The Finer Points of Diagnosis, Test Interpretation, and Treatment by Drs Siebecker & Sandberg-Lewis
How to Interpret Hydrogen Breath Tests by Dr Ghoshal
Implementation and Interpretation of Hydrogen Breath Tests by Dr Eisenmann et al



(1) http://www.siboinfo.com/overview.html

(2) Small intestinal bacterial overgrowth syndrome; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2890937/

SIBO updates from Drs. Siebecker and Sandberg-Lewis

SIBO test interpretation

New article from Drs. Siebecker and Sandberg-Lewis

Confused about how to interpret the results of breath tests?  Dr. Sandberg-Lewis and I recently published an article with pictures of many test examples and scenarios of interpretation.  See it here in the Jan NDNR edition online.

Note: The article was written before Dr. Pimentel presented his new methane level of 3ppm as positive at the SIBO Symposium (see below)

SIBO Symposium highlights

New info from the 2014 SIBO Symposium

For anyone who missed it — the 2014 SIBO Symposium webinar recordings are now available for purchase, either as individual classes or together as the whole. It was a fantastic event packed with info. Between webinar participation and in person, close to 600 people attended the symposium. We’re planning the next Symposium for 2015 (date to be determined).

Dr. Sandberg-Lewis and myself lecturing.

Dr. Pimentel lecturing in front a sold-out audience.

Here are some points of interest from the symposium (from the notes of Dr. Nirala Jacobi and myself):  

  • SIBO is caused by something (obstruction, decreased motility/ICC damage, non-draining pockets…); don’t stop at SIBO treatment — find the cause
  • Cdt B toxin from bacterial food poisoning, triggers autoimmunity to vinculin on ICC nerve cells, slowing motility — the cause of a majority of SIBO cases is autoimmune nerve damage
  • Too much protein for dinner during the prep diet (a big steak) is contraindicated as it slows transit
  • Hard-aged cheese, which is lactose free, is OK on the prep diet
  • Methane of 3ppm at any place during the lactulose test is positive
  • Flat lining of both hydrogen and methane on the test is indicative of hydrogen sulfide gas
  • Rifaximin is bile-soluble but not water-soluble — it can penetrate the small intestine biofilm and then loses effect in the large intestine due to crystallization
  • Neem potentiates other herbals
  • .5mg Resolor (prucalopride) is a good starting dose for SIBO prevention in most — previous common starting dose was 1mg
  • Leaky gut is only present in about half of SIBO patients and heals within one month of eradication — without supplements
  • Leave 4-5 hours between meals on any SIBO Diet to allow MMCs — no snacking
  • Clover honey has a 50:50 glucose to fructose ratio- according to breath testing, it absorbs normally in fructose malabsorbers

Questions? –See the webinar recording

New Youtube video

Great 6 minute video Interview with Dr. Pimentel on IBS and SIBO


New podcast interview

With Dr. Siebecker — I really enjoyed this one because hosts Darren and Diane asked me some different questions than I usually get and were wonderful to chat with:  Wellness Warrior Radio

Updated handout

SIBO Symptomatic Relief Suggestions” has been updated to include a homemade electrolyte recipe

Update to website

Discussion of semi-elemental formula was removed since clinically these have not proven effective. (not to be confused with elemental formulas which have an excellent success rate)

New FODMAP book

Diet inventors Drs. Shepard and Gibson came out with an official book last year — The Complete Low-Fodmap Diet.  It contains both explanations and recipes.

Hot Off the Press — 2014 PubMed Articles on SIBO:

2014 FODMAPs Articles


Dr. Allison Siebecker, ND, LAc

Our mailing address is:
Dr Allison Siebecker
Portland Or

Portland, Or 97086

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SIBO Symposium Jan 18-19,2014 In Portland, OR + Live Webinar

Dr. Allison Siebecker is thrilled to announce the first ever SIBO Symposium scheduled for  Jan. 18-19, 2014 in Portland, Oregon and by Live Webinar.  

All are welcome to attend this one-and-a-half-day conference, either in person or from a distance via live webinar.  
CE/CMEs are available for physicians (CMEs pending approval). 

We are honored to have Dr.s Pimentel and Weinstock joining Dr. Allison Siebeceker and Dr. Sandberg-Lewis as speakers.  “I can hardly wait to hear what they have to tell us!  Take a look at this phenomenal video of Dr. Pimentel to see the type of information that will be discussed:” stated by Dr. Siebecker.
Dr Pimentel at GALA

SIBO Symposium:
Current Perspectives &
Management of IBS
January 18-19, 2014
Portland, Oregon

Join NCNM and the SIBO Center in welcoming the leading experts in the field who will share their knowledge on the relationship between SIBO, IBS, and other associated conditions.  (Click on “Learn more and Register”  to continue to registration page).
Learn more and Register


What are the best strategies for managing SIBO? Hear three approaches from our speakers, presented in algorithm flowchart form. Test criteria, treatment options, order of treatments, prevention and relapse will all be discussed along with how to handle the incurable SIBO patient.

SIBO Symposium participants will be able to:

  • Apply diagnosis and treatment approaches for SIBO in the clinical setting
  • Understand different options for management of SIBO
  • Understand the role of prevention in SIBO
  • Understand approaches for the incurable SIBO patient


Topics include but are not limited to:

  • Pathophysiology of carbohydrates and gas in symptom generation in SIBO
  • Using and understanding breath testing
  • Discussion of treatment options: Antibiotics, elemental diet, herbal antibiotics, and other treatments
  •  Discussion of various SIBO diets (GAPS, SCD, low FODMAP, Cedars-Sinai), why they helps, pros and cons of each diet, and how to incorporate them into clinical practice
  • Order of treatment for those who need more than one
  • Symptom evaluation and re-testing
  • Prevention, including prokinetics, diet, meal spacing, and more
  • Assessment and treatment options for relapses
  • Incurable case management


Dr. Allison Siebecker,ND,MSOM,LAc Joins C Diff Foundation

We take this opportunity to welcome Dr. Allison Siebecker,ND,MSOM,LAc  to the C Diff Foundation Board of Directors.  

Dr. Allison Siebecker, ND, MSOM, LAc, has worked in the nutritional field since 1988 and is a 2005 graduate of The National College of Natural Medicine (NCNM) where she earned her Doctorate in Naturopathic Medicine and her Masters in Oriental Medicine.  In 2005 and 2013, she received the Best in Naturopathy award from the Townsend Letter for her articles “Traditional Bone Broth in Modern Health and Disease”(2005) and “Small Intestine Bacterial Overgrowth: Often Overlooked Cause of IBS” (2013).  

After practicing primary care, functional endocrinology and facial rejuvenation acupuncture, she took a sabbatical to study small intestine bacterial overgrowth (SIBO).  Currently, Dr Siebecker is instructor of Advanced Gastroenterology at NCNM in Portland, OR, where she specializes in the treatment of SIBO at the NCNM Clinic

Dr Siebecker is the author of the educational website siboinfo.com, teaching continuing education classes for physicians and is writing a book synthesizing the SIBO data into one source.