You’ve heard of Irritable Bowel Syndrome (IBS), Crohn’s disease, leaky gut syndrome and probably even Ulcerative Colitis…but what on earth is this SIBO I keep hearing about?!

It’s Small Intestinal Bacterial Overgrowth, and it may be lurking when (and where) you least expect it.

This article is going to be a primer on what the symptoms of SIBO are, how it’s related to IBS, how to test for it, and what steps you can take to start re-balancing your gut when you’ve been diagnosed with it.

What does it mean to ‘have good gut health’?

As we talked about last week, there really isn’t a definitive way to measure this, but basically, a healthy gut = a healthy microbiome.

This encompasses a diverse, but balanced population of beneficial microorganisms within the gastrointestinal tract or the gut, which can help crowd out the “bad bugs”.

You’re probably acquainted with keeping the large intestine or colon nice and healthy, and well populated with good bacteria (got probiotics?), but what about the health of the small intestine that precedes it?

It doesn’t get quite the same attention as the big guy because we seem to think that the large bowel is where all the serious business happens!

However, all nutrient absorption happens in the small intestine, so you can imagine the negative domino effect that could ensue when the flora in this vital stretch of digestive highway goes awry.

What is SIBO? What are the symptoms?

Well, small intestinal bacterial overgrowth or SIBO, is just that – when bacteria (or other microorganisms, good or bad) grow out of control in the small bowel, which should remain relatively low in bacterial count, as compared to the colon.

Colonization of this area also ends up damaging the cells lining the small intestine otherwise known as leaky gut (or an increase in intestinal permeability), which also impairs the digestive process and overall absorption of nutrients.

This can exacerbate nutritional deficiencies, and can allow toxins, pathogens and undigested protein molecules to enter the bloodstream that in turn, cause widespread inflammation, food sensitivities, autoimmune disorders, and other immune reactions.

The most common symptoms of SIBO are:

  • Nausea and/or vomiting
  • Abdominal bloating or distention
  • Abdominal pain or discomfort
  • Acid reflux or heartburn
  • Excessive gas or belching
  • Constipation and/or diarrhea
  • Malabsorption issues and malnutrition
  • Weight loss or weight gain
  • Joint pain
  • Fatigue
  • Skin issues like rashes, acne, eczema and rosacea
  • Asthma
  • Depression
  • Restless legs syndrome
  • Histamine intolerance

As we mentioned, one of the biggest concerns with SIBO is that it can lead to malnutrition, whereby essential nutrients, protein, carbohydrates and fats aren’t properly absorbed. This causes deficiencies of iron, vitamin B12, calcium and deficiencies in the fat-soluble vitamins — vitamin A, D, E and K. [1]

You may be wondering why the symptoms sound curiously similar to IBS?

One of the most common conditions associated with SIBO is irritable bowel syndrome. [2]

As a matter fact, studies have found that SIBO is concurrent in more than 50% of all cases of IBS and successful elimination of bacterial overgrowth in the small intestine reportedly resolves symptoms of IBS too.

What causes SIBO?

According to experts, the causes are not clearly defined but causes of SIBO can include:

  • Aging
  • Diabetes
  • Chronic Pancreatitis
  • Diverticulosis
  • Endometriosis
  • Injury to the bowel
  • A structural defect in the small intestine called blind loop syndrome
  • Intestinal lymphoma
  • Immune system disorders like scleroderma
  • Recent abdominal surgery
  • Celiac disease is also associated with an increased risk for developing SIBO, and can be of particular concern, as it disturbs gut motility leading to improper small intestine functioning. [3]
  • The use of certain medications, including immunosuppressant medications, and proton pump inhibitors (acid reflux medications) as well as heavy metal toxicity, low stomach acid, inflammatory diets, and stress – are all thought to be contributors as well.

How can you test for SIBO?

A lactulose or glucose breath test, which measures hydrogen and methane.  These gasses are not produced by humans and their presence signify the metabolic byproducts of carbohydrate fermentation by bacteria.  These tests are relatively inexpensive, not invasive, and can be performed at home.

How can you treat it?

Most holistic health practitioners advise strictly using the “SIBO diet” for at least 2 weeks – which may include any or all of the following:

  • Herbal antibiotics
  • Low FODMAP, SIBO Specific Diet, SIBO BI-Phasic Diet, GAPS, and/or AIP diet
  • Stress management
  • Re-populate good bacteria using probiotics, and then feed with prebiotics
  • A prescription antibiotic or prokinetic may be needed in more severe cases to get the overgrowth under control.

What are FODMAPs?

It’s an acronym for Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, and Polyols.


Basically, they’re foods that aren’t fully absorbed in the body and end up fermenting in the gut. This fermentation creates byproducts that actually feed the bacteria, making it more difficult to fight SIBO and its many (frustrating!) associated symptoms. These includes foods like barley, yogurt, apples, apricots, pears, cauliflower, garlic and onions.

This is a very popular diet for SIBO (and IBS) as it is the least restrictive in that it allows certain vegetables, fruit, nuts, grains, legumes, low-lactose dairy, etc. The Monash University developed the diet and regularly tests new foods for FODMAPS. It offers an app with comprehensive list of low/medium/high FODMAPs and serving sizes. It is important to note that this diet should only be implemented short term, as FODMAPs are needed to feed the beneficial flora in the colon.

What is GAPS?

The GAPS, or Gut and Psychology Syndrome diet, was created by Dr. Natasha Campbell- McBride. Fermented foods, lika raw sauerkraut, are an important component of this diet. Foods eliminated by the GAPS diet:

  • Processed foods
  • All grains
  • Processed sugar
  • Starchy carbs and potatoes
  • Artificial chemicals and preservatives
  • Conventional meat and dairy

What is the Specific Carbohydrate Diet (SCD)?

This diet was popularized by Elaine Gottschall in the book Breaking the Vicious Cycle and is great for those with IBDs like Crohn’s or Ulcerative Colitis. The diet restricts grains, starchy vegetables, lactose, some legumes, and most sweeteners. It involves an introductory phase and reintroductions as the gut heals.

What is AIP?

This stands for the Autoimmune Protocol and Dr. Sara Gottfried, MD and Author of Younger says, “The Autoimmune Protocol (AIP) is a very restrictive diet that removes foods considered to be gut irritants. The AIP is a stricter version of the Paleo diet, which involves the elimination of grains, legumes, dairy, and processed foods.

The AIP can be very difficult for many people to follow, but sometimes it’s temporarily necessary to fully heal a very leaky gut.”

Foods eliminated on the Autoimmune Protocol (AIP) Diet:

  • Grains
  • Legumes
  • Dairy
  • Eggs
  • Nuts and seeds
  • Nightshades
  • Industrial seed oils and all processed foods
  • Alcohol
  • Sugar, starches, fruits, yeasts, FODMAPs – especially when beginning the protocol

What is the SIBO-Specific Diet?

This diet was developed by Dr. Alison Siebecker, a naturopathic doctor specializing in SIBO. It’s a combination of the Specific Carbohydrate Diet & the Low-FODMAP diet.

What is the SIBO Bi-Phasic Diet?

This is a 3-month protocol developed by Dr. Nirala Jacobi, a naturopathic doctor specializing in SIBO. It is a variation of the SIBO-Specific Diet but implemented in phases.

What else should I know?

It may also be prudent to supplement with the following when treating SIBO:

  • Vitamin B12 – sublingual, therapeutic dose
  • Vitamin D
  • Vitamin K
  • Probiotics
  • Prokinetics
  • Digestive Enzymes
  • Iron
  • Zinc

Successfully treating SIBO is not always easy and may involve major dietary changes and medication or herbal treatment for an extended period of time.

Dr. Chelsea Gronick, ND says your goals for tackling SIBO should be 3-fold:

  • Reduce and eradicate the bacteria using a combination of diet, antibiotics, and botanical antimicrobials.
  • Heal the lining of the digestive tract.
  • Prevent reoccurrence.

When treating SIBO symptoms, the most important thing is to give your body time to repair while fighting the bacterial overgrowth.

Many find that eliminating FODMAPS from your diet for two weeks, and then transitioning to the GAPS diet or AIP protocol, can jump start the healing process and reduce symptoms!

However, getting your gut microbes re-balanced and figuring out the root cause will likely prove to be the most important step in regaining your health.

“Until you get to the underlying root cause of your digestive issues, relief from medications will be temporary.” ~ Dr. Chelsea Gronick, ND and SIBO Specialist


Credits & references:




City photo created by katemangostar –