SIBO Small Intestinal Bacterial Overgrwoth

Abdominal pain, cramps, bloating, diarrhea, and a distended abdomen are typical symptoms of SIBO. The abbreviation stands for "Small Intestinal Bacterial Overgrowth" or "Bacterial Overgrowth of the Small Intestine".

In the US, approximately 50 million people suffer from irritable bowel syndrome and according to studies, up to 70% percent of irritable bowel patients are affected by SIBO or small intestinal bacterial overgrowth.

Table of Contents

  • What is SIBO?

  • Diagnosis of SIBO

  • Causes of SIBO- Harmful bacteria in the small intestine

  • Do you suffer from SIBO?

  • How is SIBO diagnosed? The breath provides information

  • Irritable Bowel Syndrome and SIBO

  • Therapy for SIBO

  • Are herbs sufficient against SIBO?

  • Possible consequences of SIBO

  • Absorption disorders of fat, proteins, carbohydrates, and B12

  • Formation of gas and fusel alcohol by carbohydrates in SIBO

  • Maldigestion of fats in SIBO

  • Nutrient deficiencies in SIBO

  • Disturbed mobility of the intestine

  • Either - Or - Breaking the cycle in Sibo

  • Nutrition and SIBO

  • Alleviate symptoms: Low-FODMAP- helpful in the short term at best

  • SCD - reduces specific carbohydrates

  • Conclusion on therapy options for SIBO

What is SIBO?

In SIBO, bacteria are present in the small intestine. In healthy people, bacteria are absent or barely present in the small intestine. The diagnosis of SIBO/ small intestinal bacterial overgrowth means that the number of bacteria present in the small intestine is increased by more than 100 times normal levels.

This happens, among other things, when the bacteria from the large intestine succeed in migrating into the small intestine. This happens for a number of reasons.

The diagnosis of SIBO can be made by an alternative practitioner or physician.

In almost all cases, a so-called SIBO breath test is well suited for diagnosis, since certain gases in the breath can indicate SIBO and can be measured (more on this below).

Symptoms such as abdominal pain, a bloated belly, diarrhea, but also constipation, depression, brain fog/drowsiness, and poor skin conditions are indications of SIBO bacteria in the small intestine.

Diagnosis of SIBO

Many of us take a functioning digestive system for granted. But as soon as our digestion is off track, it starts to negatively affect our everyday lives. The more our digestive system chronically lets us down, the more aware we become of our symptoms. It can control your life.

If no cause is found in conventional medicine, one can be well advised to insist on having SIBO ruled out by an alternative practitioner or doctor.

How this can be done from home is described in more detail below. The laboratory breath test (see SIBO Tests) has the highest sensitivity for methane and hydrogen gases. But now back to SIBO.

Under normal circumstances, it is hardly possible for bacteria from the large intestine to enter the small intestine. But how can SIBO occur?

Causes of SIBO- Harmful bacteria in the small intestine

Our small intestine, compared to the large intestine, is very low in bacteria. A major cause of SIBO is impaired intestinal motility.

A valve naturally separates the small and large intestines. When there is increased gas formation in the large intestine, the high pressure can open the so-called Bauhin Flap (ICK), which is the boundary between the large and small intestine, and bacteria can then penetrate from the large intestine into the small intestine.

In a healthy person, the intestine cleans itself several times a day by cleansing waves, especially at night. This occurs through a downward contraction of the intestinal tube (peristalsis).

In this process, any remaining food remnants are moved through the intestines, and the intestinal wall is cleaned.

Bacteria can also be "pushed" from the lower small intestine back into the colon during the "cleaning wave". If the cleansing waves are absent or if too few of them take place, the ascending bacteria may succeed in colonizing the small intestine.

Causes for missing or reduced cleansing waves can be found further down in the text.

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Do you suffer from SIBO?

SIBO pain and suffering

This can only be confirmed or checked by a breath test at a gastroenterologist's office or with a SIBO breath test taken at home. Initial indications for the breath test are already given by the symptoms and the differential diagnosis.

If you have irritable bowel syndrome or additional indications are given by the corresponding medical history and symptoms, a SIBO breath test for SIBO can be performed as a simple option. The test is easy to perform at home.

Further indications are information about any past infections with antibiotic therapy or past food poisoning and should be included in the medical history with an alternative practitioner or appropriate therapist.

Another indication of SIBO is when symptoms are minimal in the morning, after getting up or after longer breaks from eating, but then return, about 40 to 120 minutes, after eating with the symptoms typical of SIBO (e.g., flatulence).

In many patients, these symptoms occur more frequently in the evening.

Summary of possible symptoms of SIBO:

  • Bloating

  • A distended abdomen, possible with pain when pressure is applied

  • Abdominal pain, cramping pain

  • Constipation

  • Diarrhea

  • Altered stool frequency

  • Difficulty concentrating/ brain fog

  • Fatigue/ exhaustion

  • Anxiety disorder/ depression

  • Nausea/ heartburn/ upper abdominal discomfort

  • Bad breath

  • Blemished skin

  • Nutrient deficiencies

  • Lactose intolerance, gluten intolerance

  • Headaches

Poor nutrient absorption can lead to long-term weight loss and nutrient deficiencies. This can eventually lead to further secondary diseases. SIBO is also considered a possible cause of leaky gut syndrome.

Early detection of small intestinal malabsorption increases the likelihood of successful treatment and can prevent the development of secondary diseases.

How is SIBO diagnosed? The breath test provides information.

To perform the breath test, you start by drinking a specialized solution (water with sugar: either synthetic sugar or Glucose) at home. Then the concentration of hydrogen and methane in your exhaled air is collected at regular intervals. You send your test to a laboratory and the results are evaluated.

SIBO Breath tests are very accurate as the solution you ingest can only be processed by the bacteria that cause SIBO and then formed into hydrogen and methane.

Hydrogen and methane can then be measured very accurately in "parts per million" (ppm) in the laboratory.

The solution you ingest takes a certain amount of time to reach the small intestine.

If the hydrogen and methane gas content in your exhaled air increases within 120 minutes or, in the case of slowed intestinal passage, even later, this means, according to the principle of the test, that SIBO bacteria are present in the small intestine.

In addition, this SIBO breath test can be used to interpret where in the small intestine the bacteria are located based on the elapsed time and the timing of the increase of hydrogen and methane. This has a crucial impact on recommendations for therapy.

Irritable Bowel Syndrome and SIBO

The symptoms of SIBO and irritable bowel syndrome (IBS) are very similar. That is why a good diagnosis is key to finding the cause of the symptoms. For example, IBS can be a cause of SIBO due to the altered motility of the bowel.

Conversely, SIBO is also a trigger for irritable bowel syndrome. Currently, irritable bowel researchers such as Dr. Pimentel and Dr. Siebecker (USA) are discussing whether in certain cases irritable bowel syndrome can be caused by SIBO or whether, vice versa, irritable bowel syndrome is causative for SIBO.

Which came first is a classic chicken and egg question.

The fact is that both conditions have a mutually reinforcing influence. Successful treatment of small intestinal malabsorption can certainly lead to enormous improvements in the symptoms of irritable bowel syndrome!

Treatment and therapy for SIBO - Bacterial Overgrowth of the Small Intestine

Irritable Bowel Syndrome

Simply "taking a few herbs" will rarely lead to success. It is not for nothing that SIBO has a very high relapse/recurrence rate with blanket therapy, even though herbs may come across as naturopathic.

Herbal extracts and other herbal agents can of course be used very well, but it depends on the correct individual application. Here, too, a patient consultation forms the best basis for therapy planning.

With SIBO, damaged mucosa of the small intestine can no longer fully absorb micro- and macronutrients, bacteria can then access these nutrients as food, allowing the bacteria to multiply even more.

SIBO sufferers take a double hit from this cycle. On the one hand, important nutrients are missing and on the other hand, the essential intestinal flora in the small intestine deteriorates further due to harmful bacterial growth. A negative cycle is created.

Formation of gas and fusel alcohol by carbohydrates in SIBO

Bacterial fermentation of carbohydrates in the small intestine produces the gases, methane and hydrogen.

According to the dictionary, the term fermentation is defined as the formation of acid, gas, and alcohol. Each individual component in itself has an irritating effect on the intestinal wall and its mucous membrane.

A good SIBO breath test should be able to detect these two gases and additionally measure carbon dioxide.

Furthermore, damage to the intestinal cells (enterocytes) can lead to secondary lactose intolerance, as lactase formation can no longer take place to its full extent. Secondary means that as a result of damage to the intestine by SIBO, lactose intolerance has been caused.

Maldigestion of fats with SIBO

Due to the bacterial breakdown of bile acid in the small intestine, fat from food is no longer able to be absorbed or fully emulsified. Emulsification of fat is necessary to divide (emulsify) a fat droplet into many smaller fat droplets and thus to facilitate absorption through the intestinal mucosa.

Nutrient deficiencies in SIBO

The bacteria present in SIBO can directly metabolize iron and vitamin B12 causing possible vitamin deficiencies. If the stomach is additionally inflamed, the absorption of B12 in the small intestine is further reduced.

In severe cases, anemia can then develop. Long-term, secondary diseases can arise. Iron, zinc, and B12 deficiencies have been scientifically confirmed in studies of SIBO patients. The question remains open as to what other nutrient deficiencies may develop.

Impaired motility of the intestine

If the movement (motility) of the intestine is reduced, the automatic cleansing process cannot take place to its full extent.

Causes of inhibited motility of the intestines are stress or psychological influences, diseases of the musculoskeletal system, scarred intestinal tissue such as after an operation in the abdominal cavity or accidents, major appendectomies, pain, but also medication.

Many factors affect our autonomous nervous system which controls the systems you don’t have to think about - breathing, heart rate, digestion, etc.

You can think of the Autonomous Nervous System (ANS) as a network of roads in the body, and the main highway runs directly from the head to the abdomen. This main highway is the vagus nerve.

The ANS is thus directly connected to the gut and regulates its mobility, among other things. If we are stressed (there are many forms of stress), the activity/mobility of the intestine changes and the frequency of the automatic cleansing process decreases.

Either - Or - Breaking the Cycle of SIBO

The intestine basically knows only two modes, digestion or cleansing. Either the intestine processes food and absorbs nutrients or the intestine cleanses itself through the MMC.

Cleansing during digestion is not possible. This means that if something is eaten every 2 hours during the way, the intestine can only start the cleansing work at night. The "cleansing wave” runs through the intestine up to three times a minute and is of great importance in preventing small intestine colonization.

It is a good recommendation not to snack between meals or better to skip snacks and instead give the intestines time to cleanse themselves between meals.

The "gurgling" sound that some people sometimes find embarrassing is often the cleansing sound of the intestines. When you hear this sound, you can be happy because your bowels are cleaning up for you!

Nutrition and SIBO

Of course, diet also has a major impact on gut flora and gut motility. For example, frequent consumption of FODMAPs, which is a group of foods containing easily fermentable carbohydrates, is considered unfavorable for SIBO or irritable bowel syndrome. Bacteria can ferment these carbohydrates in the small intestine, which causes symptoms.

Examples of FODMAPs include all starchy foods such as potatoes, rice, and pasta. Cereal products (wheat, spelt, oats, etc.), legumes, garlic, onions, fructose, lactose, and many more food items are also FODMAPs.

Avoiding high FODMAP foods results in the possible starving of the bacteria and reduction of symptoms. However, it is not possible to completely avoid all FODMAPs without a major dietary change such as the Low-FODMAP diet.


The Low-FODMAP diet is not a long-term solution to SIBO or small intestinal malabsorption. Rather, it aims to treat symptoms.

In most cases, the Low-FODMAP diet is unsustainable due to its complicated and laborious implementation. Every handout and table listing low-FODMAP foods varies. Uniform guidelines cannot be found.

We would like to note that a Low-FODMAP diet for a period longer than three months can lead to other problems such as a reduction in the biodiversity of the intestinal flora and nutrient deficiencies.

What the Low-FODMAP diet does offer (with the right food choices) is targeted food deprivation for the SIBO bacteria, allowing them to reduce their activity, even if only for a short time, and thus lead to an improvement in symptoms.

However, since there is by no means a complete eradication of the bacteria, they continue to be present in low activity (the breath test for SIBO is then also negative). As soon as normal food is eaten again, the bacteria will start to multiply. With the Low-FODMAP diet, a longer symptom-free period can be achieved until symptoms reoccur. This can be extremely positive for the psyche and motivation of those affected.

SCD- reduce special carbohydrates

The Specific Carbohydrate Diet (SCD), often recommended for Crohn's disease, appears to be easier to implement. The SCD is perceived to be easier to implement because more foods are "allowed." The SCD also represents "only" a treatment of symptoms.

Starving out the bacteria, as some would imagine happens with the Low-FODMAP diet, is not possible here either. However, a longer implementation of the SCD to control/alleviate symptoms, as well as improve psychological complaints, and the possibility to draw new strength seems plausible.

Conclusion on therapy options for SIBO

The Low-FODMAP diet and SCD are possible short-term ways to relieve symptoms and regain strength and motivation. In our opinion, there are by no means a long-term solution, as presented by some online sources, since the diets entail an excessive restriction to the quality of life as well as a health risk due to an unbalanced diet and a resulting dysbiosis.

Rather, a long-term elimination/eradication of the existing SIBO bacteria should be the primary goal. Here, an experienced therapist is strongly advised, as targeted interventions in the intestinal flora, combined with a stepwise approach on several levels, must take place.

SIBO IBS Expert Call Free

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Your first step to a happier and healthier life.

Are you tired of feeling bloated, gassy and uncomfortable after every meal? Do you suffer from cramps, diarrhea or constipation?

Then talk to one of our Experts and let them guide you.