Balance, harmony, and diversity are common words used to describe a healthy gut flora. These descriptions are completely accurate to strive for, but they can also be somewhat abstract. It is not uncommon that the more one learns about the gut’s impact on the entire body, the more questions arise. What is actually an “optimal” bacterial composition, and how does the bacterial flora in the small intestine differ from that in the large intestine? These questions are crucial when discussing the gut disease known as SIBO.

What is SIBO?

Our digestive system is divided into two parts: the large intestine and the small intestine. The digestive system starts at the stomach and ends at the anus. Additionally, the large and small intestines can be further divided into smaller parts, such as the duodenum and the appendix, for example. To keep it simple, let’s focus on the division between the large and small intestines. SIBO stands for Small Intestinal Bacterial Overgrowth. It means that there is an overgrowth of bacteria in the small intestine. In a healthy gut flora, the overwhelming majority of bacteria reside in the large intestine. The bacteria in the large intestine are important for our immune system, the production of K and B vitamins, and the breakdown of carbohydrates that were not processed in the earlier stages of the digestive system. A small amount of bacteria is also naturally present in the small intestine, primarily lactobacilli and streptococci. When there is an increase in bacterial flora in the small intestine, it is a sign that something is not right. It does not mean that these are “bad” bacteria but rather that the bacteria are in the wrong location – in the small intestine instead of the large intestine.

IBS and SIBO – considering the whole picture

Many individuals with SIBO also suffer from IBS (irritable bowel syndrome). Studies have shown that 80-85% of people with IBS also have an excess of bacteria in their small intestine. It is difficult to say with 100% certainty which condition causes the other – it is somewhat of a chicken-or-egg situation. However, what we can say is that the digestive system should be seen as a whole. If you consume a lot of fast carbohydrates, drink alcohol excessively, and regularly experience stress and anxiety, it is not surprising that both the large and small intestines are affected. Taking a holistic approach to your body means considering its components, including the gut, in relation to the whole. Identifying the underlying causes of your problems is a first step that often has a surprisingly positive effect for those who don’t know where to start. Minimizing stress levels, making time for exercise, and adjusting your diet are good second steps.

SIBO – causes of its occurrence

The overgrowth of bacteria in the small intestine can be caused by one or several factors. Some are related to lifestyle, while others are beyond our control. It can be caused by:

• Poor diet – high intake of sugar, refined carbohydrates, and alcohol
• Low stomach acid levels – due to stress and/or medication
• Imbalance in the gut flora – due to poor diet, antibiotic treatment, and/or medications for acid reflux
• Pockets or other structural defects in the small intestine
• Age

SIBO can occur after a surgical procedure or as a result of a disease. This can create a pocket or a similar condition that slows down the digestive process and creates a breeding ground for bacteria. In some cases, surgical intervention may be necessary to address this, but antibiotic treatment is the most common approach, or using antiseptic herbs. Regardless of the cause, it is important to seek medical assistance in such cases.

SIBO – common symptoms

Symptoms of SIBO can vary greatly depending on the bacteria causing the overgrowth. This often makes it challenging to definitively rule out other conditions or diseases. Here are some common symptoms that may occur depending on which bacteria or combination of bacteria are dominant:

• Diarrhea
• Bloating
• Excessive gas
• Abdominal pain
• Constipation
• Nausea
• Fatigue
• Depression

Serious complications of SIBO – malnutrition and vitamin deficiency

A common result of SIBO is impaired absorption of essential nutrients. This applies to many other digestive-related issues as well. If the absorption of macronutrients (protein, carbohydrates, and fat) is compromised, it can lead to malabsorption and sudden weight loss. The absorption of micronutrients (vitamins and minerals) can also be affected. It is not uncommon for individuals with SIBO to have deficiencies in important vitamins such as vitamin D and vitamin B12. In these cases, these substances simply pass through the digestive system without being properly absorbed. Vitamin B12 deficiency is a common problem worldwide, especially among vegetarians, vegans, and individuals with SIBO. B12 is essential for optimal red blood cell production, and a deficiency in this vitamin can lead to anemia.

Two types of SIBO – hydrogen and methane

When the bacteria in the small intestine thrive on carbohydrates that pass through, hydrogen is produced. This leads to water being drawn into the intestine, causing diarrhea. Over time, this can also lead to a deficiency of the enzyme lactase, which is needed to break down lactose into glucose and galactose. The other type of SIBO – the methane variant – has the opposite effect. Instead of diarrhea, it generally causes constipation. Methane is produced when there is an excess of archaea or archaeal bacteria in the small intestine. The hydrogen produced earlier is captured by archaea and converted into methane. An excess of methane is a common cause of constipation in both SIBO and IBS. Gettested’s SIBO test measures both methane and hydrogen levels in your breath, providing a comprehensive overview of your condition. SIBO tests can also be performed at functional medicine clinics but are not offered at general healthcare centers.

SIBO – dietary and lifestyle changes

SIBO can occur either as a result of lifestyle factors or after a surgical procedure or illness. It is important to determine the underlying cause of the problem so that appropriate actions can be taken. Taking positive steps towards good health is fantastic regardless of your situation, but it is always reassuring to have a clear understanding of what your body may be lacking and what you can personally influence. Perhaps you only need to supplement your diet with vitamins or dietary supplements, or maybe you need to reconsider your overall situation. Regardless of the circumstances, remember: It is never too late to embark on a journey towards better health and increased quality of life.

What does SIBO stand for?

SIBO is an abbreviation for the condition known as Small Intestinal Bacterial Overgrowth.

How does a SIBO test work?

Our SIBO test is a breath test that you can easily perform at home. The test measures the levels of methane and hydrogen in your exhaled breath and is conducted multiple times throughout the day. Before the test, you will drink a lactulose solution. After all the samples have been collected, you will send the test back to our laboratory for analysis. Detailed instructions for the process are included in the test kit, which can also be found on our website here about SIBO.

Author profile: Johanna

Johanna is a certified professional health coach with over a decade of experience in the field. She specialises in helping individuals navigate their health journeys, whether they are dealing with chronic conditions, working towards weight management goals, or seeking to improve their overall wellbeing.

Johanna is also a prolific contributor to our blog, where she shares expert insights, tips, and advice to help you stay healthy. She is passionate about ensuring our readers have access to the latest research and information. For personalised health advice, consider scheduling a consultation with us.