What is SIBO (Small Intestinal Bacterial Overgrowth)?

SIBO stands for small intestinal bacterial overgrowth and is the most common cause of irritable bowel syndrome (IBS). SIBO occurs when bacteria normally present in the large intestine is found in large amounts in the small intestines.

The location of the bacteria is the main problem rather than the bacteria itself. The small intestines should only be home to a small amount of bacteria. In contrast, the large intestines need a large number of bacteria to help complete digestion.

The small intestine should only have about 100,000 bacteria per ¼ teaspoon of content. In contrast, the large intestine has as many as 20 billion bacteria per ¼ teaspoon of content.

What’s the problem with these bacteria being in the small intestine?

The bacteria will fight for all carbohydrate and sugar sources to feed themselves. They rob us of our food and nutrients and cause it to ferment. This fermentation produces the hydrogen and/or methane gas. Humans don’t produce these gases, they are only produced by the bacteria.

Managing IBS for Shorter Symptom Duration

These excess gases cause the bloating, burping, flatulence and pain. The type of gas produced can also mean your symptoms tend more to constipation or to diarrhea.

Both hydrogen and methane also cause damage to the microvilli that line our intestines. This causes leaky gut or increased intestinal permeability. Your gut when working properly acts as a filter, letting the nutrients in while keeping the toxins out.

When the gut becomes ‘leaky’ it allows toxins and larger, undigested food particles to get through. This can cause symptoms like joint pain, headaches or skin breakouts depending on your individual areas of susceptibility.

The small intestine can also have its motility damaged by SIBO. The cleansing wave or migrating motor complex (MMC) is a muscular contraction that moves content along at regular intervals throughout the day and is affected by SIBO and may no longer work properly. This MMC can also be impaired by stress and eating too often.

Symptoms of SIBO

People with SIBO often experience one or more of the following symptoms:

Bloating and abdominal distention

Excess gas (flatulence and/or burping)

Cramping, abdominal pain or discomfort of the abdomen

Constipation and/or diarrhoea (or alternating)

Fibre often causes symptoms to worsen

Indigestion & nausea

Fatigue

How common is SIBO?

The presence of small intestinal bacterial overgrowth is very common. It has been estimated that up to 80% or more people who suffer from irritable bowel syndrome (IBS) also have this issue. The prevalence being unknown among healthy individuals.

Doctors assume that it’s often under-diagnosed because mild cases may be symptomless while moderate ones feature many non-specific symptoms which overlap other conditions.

SIBO sufferers may also suffer at least one of these symptoms:

GERD / acid reflux

Headaches / migraines

Abdominal pain

Fat Malabsorption

Poor absorption of nutrients

Food intolerances / food sensitivities

Leaky gut

Nutritional Deficiencies

Depression or mood issues

Obesity

Hormonal imbalance

Joint pain

Skin issues (eczema, breakouts, rosacea)

Brain fog / concentration issues

From this list you’ll see that the symptoms affect more than just our digestive system, and they can affect just about any organ.

If you have small intestinal bacterial overgrowth you’ll notice a worsening of symptoms when you eat sugary and starchy foods like bread, pasta, potatoes etc. The longer SIBO has been present the more likely you are to become intolerant to more and more foods for example gluten containing foods, dairy and fructose in fruit.

Small Intestinal Bacterial Overgrowth (SIBO) has been associated with several health conditions.

These include:

Irritable Bowel Syndrome (IBS): A significant percentage of individuals with IBS have been found to have SIBO, suggesting a connection between these two conditions.

Inflammatory Bowel Diseases (IBD): These include conditions like Crohn’s disease and ulcerative colitis. While the relationship between IBD and SIBO is complex, the changes in gut motility and the use of certain medications for IBD may contribute to the development of SIBO.

Coeliac Disease: People with coeliac disease, especially those who do not respond to a gluten-free diet, are more likely to have SIBO.

Diabetes Mellitus (particularly Type 2): Diabetic neuropathy can affect the nerves of the gut, causing delayed gut transit and predisposing to SIBO.

Gastroparesis: This is a condition in which the stomach takes too long to empty its contents. Delayed gastric emptying can create an environment conducive to bacterial overgrowth.

Chronic Pancreatitis: This condition can lead to malabsorption, which in turn can predispose to small intestinal bacterial overgrowth.

Scleroderma (and Other Connective Tissue Disorders): These conditions can affect gut motility and lead to bacterial overgrowth.

Hypochlorhydria: Conditions that result in reduced stomach acid (hypochlorhydria) or taking acid-suppressing medications (like proton pump inhibitors) can increase the risk of SIBO.

Previous Intestinal Surgery (or Structural Abnormalities in the Gut): Any condition or surgery that affects the normal anatomy or motility of the gut can predispose to small intestinal bacterial overgrowth.

Keep in mind that while there are associations between these conditions and SIBO, having one of these conditions does not necessarily mean you will develop small intestinal bacterial overgrowth.

It is also important to note that the above list is not exhaustive. SIBO can be associated with other health conditions not mentioned in the list.

What causes SIBO?

A single cause of Small Intestinal Bacterial Overgrowth hasn’t been identified, but there are some known triggers and contributing factors. For many it’s a combination of factors. These are:

A bout of gastroenteritis often occurred around the time the symptoms start

Certain medications such as antibiotics, the pill, narcotics and prolonged use of proton pump inhibitors or antacid can be contributing factors

Chronic stress which lowers stomach acid and interferes with migrating motor complex (MMC)

Surgery such as appendicitis, hysterectomy or any surgery in the abdominal area that can cause adhesions

Digestive disorders such as coeliac disease, ulcerative colitis and Crohn’s disease increase the risk of SIBO

Underlying conditions such as hypothyroidism and diabetes or poor blood sugar management

A typical diet high in processed foods, refined flours and excess sugar

Alcohol and even moderate alcohol consumption have been linked to SIBO (defined as 1 drink per day for women and 2 drinks per day for men)

Glyphosate, a commonly used herbicide, acts like a low dose antibiotic, so antibiotic exposure in food is relevant

Hiatal hernia & poor stomach function and low stomach acid (hypochlorhydria)

H.pylori infection which may reduce stomach acid levels

Poor methylation and gallbladder function

Gastroparesis which causes dysmotility

Gastric bypass surgery

Structural issues like small bowel diverticulosis, small bowel obstructions or small bowel abdominal adhesions

Ileocecal valve dysfunction

Is SIBO Contagious?

One of the most common questions about Small Intestinal Bacterial Overgrowth (SIBO) is whether it is contagious. Simply put, SIBO is not contagious. It cannot be passed from one person to another through physical contact, sharing food, or other forms of direct exposure. Unlike certain bacterial infections, SIBO arises from an imbalance within the body rather than an external infection caused by a specific microorganism.

SIBO occurs due to a complex interplay of factors, such as poor gut motility, low stomach acid, or structural abnormalities in the digestive tract. These conditions create an environment where bacteria, normally confined to the large intestine, multiply excessively in the small intestine. This internal overgrowth is unique to each individual and depends on factors like their gut health, diet, medications, and underlying medical conditions.

Why Is SIBO Not Contagious?

The bacteria involved in SIBO are not foreign invaders but rather naturally occurring gut bacteria. The issue lies in their location and quantity, not their presence. For this reason, SIBO cannot spread like a viral or bacterial infection, such as the flu or food poisoning. Instead, SIBO develops due to internal disruptions like slow gut motility, surgeries, or long-term use of certain medications.

If you’re dealing with SIBO or worried about others catching it, rest assured that SIBO is not contagious. However, it’s crucial to address the underlying causes to manage symptoms and prevent recurrence. If you suspect SIBO, testing and professional guidance can help you achieve lasting relief.

For more information on SIBO symptoms, testing, and treatment options, book a free Gut Fix Strategy Session or call us at 1300 16 75 72 to get started on your path to better gut health.

What foods trigger SIBO symptoms?

While foods aren’t the original cause of small intestinal bacterial overgrowth, certain foods do encourage the overgrowth of bacteria in the small intestine. If you’re feeding them their favourite foods, they’re going to grow more, and that will trigger more of your SIBO symptoms.

You can also help reduce the overgrowth by starving the problematic bacteria of their favourite foods. This strategy has led to a number of proposed SIBO diet plans. The diets vary, and so do individual results. These include:

High FODMAP foods

Sugar alcohols

Wheat/gluten

Lactose

Fermentable oligosaccharides

SIBO Testing – the best way to discover if you have SIBO

There are two simple, non-invasive breath tests available to identify if you have SIBO. The first test is a lactulose breath test. Alternatively, a glucose breath test is available that measures the hydrogen and methane output in a single breath.
Samples are taken every 20 minutes for 3 hours and the results will tell us if you have SIBO. It also can determine approximately where in the small intestines it is present and which gas is being produced to influence your symptoms.
Both tests can be conducted in your own home after a one day preparation diet. See my SIBO Testing page for more information.

SIBO Treatment – How to Treat SIBO and Repair a Slow Gut

Addressing SIBO requires a multi-faceted approach targeting bacterial overgrowth, gut motility, and the underlying causes. The good news is there are SIBO treatments available.

The SIBO Diet

A strategic diet can help reduce symptoms and restore gut balance. Common approaches include:

SIBO Bi-Phasic Diet: Designed in phases to eliminate bacterial triggers and repair the gut lining.

Low-FODMAP Diet: Limits fermentable carbohydrates that fuel bacteria.

SIBO Diet Recipes: Focuses on easily digestible, nutrient-dense meals.

Antimicrobial Therapy

Share some details here for Service two. This is a flexible section where you can share anything you want. It could be details or some information about your service.

Antibiotics: Medications like rifaximin target harmful bacteria without significantly disrupting the gut microbiome.

Natural Antimicrobials: Alternatives like oregano oil, garlic extract, and berberine are often effective.

Gut Motility Support

Share some details here for Service three. This is a flexible section where you can share anything you want. It could be details or some information about your service.

Prokinetics like ginger or motility agents promote intestinal clearing and prevent bacterial buildup.

Lifestyle changes, including increased physical activity, can improve motility.

Nutritional Support

Share some details here for Service four. This is a flexible section where you can share anything you want. It could be details or some information about your service.

Addressing deficiencies caused by SIBO malabsorption with supplements such as B12 or iron.

Incorporating prebiotics and probiotics to support gut health.

Lifestyle and Stress Management

Share some details here for Service five. This is a flexible section where you can share anything you want. It could be details or some information about your service.

Stress impacts digestion and motility. Practices like meditation, yoga, or mindfulness can help reduce stress-induced gut issues.

Explore Gut Health with IBS Specialist Lisa Snowdon

Currently, there are no blood tests for identifying SIBO but blood results play an important role in identifying vitamin and mineral deficiencies that can lead to malnutrition. For example, there may be a risk of developing vitamin B12 deficiency that can be checked. Thyroid issues can also be tested for.

Finding a SIBO Nutritionist

My 7 step process to restore your gut health was developed to address SIBO as the most common cause of IBS.

Stop putting fuel on the fire and remove dietary triggers with either an elimination diet or elemental diet
Testing where necessary to confirm it’s SIBO, where the overgrowth occurs and which gas is being produced
Use the correct antimicrobial herbs to treat your SIBO (specific to your results and situation)
Address stress and lifestyle factors that influence your symptoms
Heal up leaky gut, reduce inflammation and reintroduce foods
Rebalance your microbiome and reduce risk factors for SIBO relapse
Get professional support and guidance so you follow the right steps in the right order

To further understand my 7-step process to restore your gut health see my Gut Fix Program.

For further information on treating SIBO see my SIBO Treatment page. For further information on functional medicine tests see my Lab Tests page.

Book a Free Strategy Session

If you’d like to find out more about the SIBO testing and natural treatment options for SIBO, IBS or other digestive symptoms then please book in for a Free Gut Fix Strategy Session so I can go over your options.

Or simply call 1300 16 75 72.

Book a Free Gut Fix Strategy Session