SIBO Small Intestine Bacterial Overgrowth

SIBO is something I get asked about all the time. It basically refers to an overgrowth of bacteria having a party and fermenting all over the shop in the small intestine as opposed to the large intestine, the colon, where we normally see it.

This has consequences for our digestion of foods, nutrient levels, especially of B12, iron, Vitamin A, and affects fat and bile levels. In more severe cases, it contributes to leaky gut, food sensitivity and endotoxins playing havoc with the brain and nervous system.

Experts reckon that up to 84% of IBS sufferers have SIBO, which is a huge number!


SIBO Symptoms

Not surprisingly, then, most of the symptoms you would associate with IBS such as:

  • Bloating
  • Wind
  • Burping
  • Nausea
  • Cramping pain
  • Acidity and reflux
  • Constipation
  • Diarrhoea
  • Erratic bowel movements


But you might also have:

  • Fatigue (often anaemic)
  • Headaches
  • Generalised or joint pain
  • Food sensitivity
  • Mood, skin or respiratory disorders
  • Malabsorption


This is by no means an exhaustive list, but it will start you off with the main conditions thought to be caused, or at least exacerbated, by SIBO.

Testing SIBO

We use a breath test for SIBO testing and the kits have greatly improved over the years so they are now pretty reliably done postally.

You basically take a measure of lactulose or glucose and then give timed breath samples. The result will show if and when you are producing excess hydrogen or methane which gives an idea if you are positive or not. I’ve written a huge SIBO Testing Guide for you on the blog, complete with a video of me going through some common test results patterns for you.

The SIBO Guide

You can read that SIBO Testing Guide here.

SIBO report

You do have to be slightly careful with the interpretation of results because you can get false positive and negatives, and misleading results if you’re not ‘au fait’ with how to read them properly. I’ve done a video going through some results for you here:

There is a also a useful rundown of SIBO testing here which might help:

SIBO- The Finer Points of Diagnosis

And here is some info on how to avoid false results best:

SIBO – Interpreting Results

If your symptoms suggest an issue and your lab results don’t, we tend to assume SIBO. If you’ve had treatment and feel tons better but your lab results suggest it is still present, I would always advise you go with your body!

There is much debate about whether you should use glucose or lactulose as the test substance and I have gone through the pros and cons of that in the testing guide for you.

Treating SIBO

To start you off, here is a fabulous resource for you: a summary from the SIBO conference 2017 in the Natural Medicine Journal with the key points from each speaker. This should set you off nicely with all things SIBO!

Takeaways from the 2017 Integrative SIBO Conference

You can also read some useful stuff here on treating SIBO:

They have a great handout on treatment options here.

I like SCD Lifestyle’s page on it here too:

Everything You Need to Know About SIBO (Small Intestinal Bacterial Overgrowth)

There’s an interesting podcast from Chris Kresser here with Dr Ken Brown where they discuss the use of Atrantil, a botanical mix designed to be taken short-term and as a maintenance dose, which seems to work especially for resistant methane-dominant cases (which are not bacteria at all..!). See here:

New Treatment for SIBO and IBS-C

And a useful very detailed post from Byron Herbalist in Australia here:



Persistent or recurrent SIBO?

Over time, I have come across quite a few people who have recurrent or persistent SIBO despite much effort! The first thing to do here is look whether the lab test is a false positive. Does the rise in gases come towards the end of the timespan and did the person use the lactulose test? If so, it could well be that the person just has a shorter bowel or faster transit time or something and they don’t have SIBO at all – especially if symptoms suggest they are OK. This is an interesting read on that:

Do you really have SIBO?

If the person does have truly recurrent or unresolving SIBO, I would be looking first at stress levels (especially past trauma or a major stress trigger just before the start of the issue or in childhood) – which could be suppressing the immune system.

I would also consider the patient’s ability to breakdown sugars and carbs with eg. a fructose test. That leads to more carb and more food for the bacteria!

And I would consider stomach acid levels which may be allowing bacteria through into the system in the first place.

There is also an association with recurrent SIBO and poor gut motility, coeliac disease and ileocaecal valve reflux (where the bacteria gets shoved back into the small intestine) to name a few. Also anything that increases sugar in the system (think diabetes) is going to be a factor. This article here is a good rundown of the risk factors in hard to treat SIBO:

SIBO – What causes it and why it’s so hard to treat!

And here is a fabulous article in the Townsend Newsletter in 2015 on testing, treatment and it includes a useful rundown of why people might relapse or not get better on page 3:

SIBO: Dysbiosis has a new name

Angie at AI Illness did a great review of one of the recent (2015) SIBO Symposiums and distilled down the key messages into a series here.

SIBO Recipes

I am often asked for SIBO recipes and I came across these excellent books by Rebecca Coomes who solved her own SIBO issues. She does a family cookbook, a Summer one and even a really useful Christmas one, plus a set of 14 day recipes that will serve for each stage of the programme: restricted, semi-restricted, remove & repair. Have a look.


OK peeps, hope all that helps – should be more than enough to start you off. Good luck!