What is that and what symptoms are typical
Content
1. What is SIBO?
2. SIBO Symptoms
3. Types of SIBO
3.1 Hydrogen-SIBO
3.2 Methane-SIBO
3.3 Hydrogen-Sulfide-SIBO
4. SIBO Therapy
1. What is SIBO?
SIBO stands for “Small Intestinal Bacterial Overgrowth,” which describes the pathological overgrowth of bacteria in the small intestine. In a healthy state, the small intestine is compared to the large intestine sparsely populated with bacteria. The bacterial load is measured in colony-forming units (CFU). In the large intestine, there are about 10^10-10^12 CFU/ml, equating to 10 billion to one trillion bacteria. In contrast, the small intestine contains only 10^2-10^8 CFU/ml, with the bacterial count increasing as you move from the duodenum to the ileum.
The prevalence of SIBO is not well-established, but estimates range between 2.5% and 22%. Estimates suggest a global prevalence of 11%. There are multiple issues that can cause SIBO development.
2. SIBO Symptoms
The overgrowth of bacteria and their production of gases and toxins in the wrong location can overwhelms the small intestine. As a result, symptoms such as abdominal pain, bloating, diarrhea, constipation, belching, feeling of fullness, and heartburn can occur. Some patients also report fatigue, difficulty concentrating, and depressive mood changes. Not all 11% of the population worldwide are affected severely enough to require therapeutic intervention, and in some cases, SIBO can be asymptomatic.
Symptoms typically appear within the first 120 minutes after eating and can be exacerbated by a diet rich in FODMAPs. FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) are fermentable carbohydrates that bacteria use as food. The foods containing these carbohydrates are varied, including for example grains, dairy products, mushrooms, cabbage, and legumes.
Symptoms usually improve after prolonged periods of fasting, with discomfort often being better in the morning and worsening throughout the day with increasing food intake.
3. Types of SIBO
There are three main types of SIBO, classified based on the primary gases produced by the bacteria: hydrogen (H2), methane (CH4), and hydrogen sulfide (H2S).
3.1 Hydrogen-SIBO
In hydrogen-dominant SIBO patients typically experience diarrhea, bloating, and flatulence. Hydrogen is a byproduct of various metabolic processes and is produced by numerous bacteria, including E. coli and Klebsiella. and flatulence. Hydrogen is a byproduct of various metabolic processes and is produced by numerous bacteria, including E. coli and Klebsiella.
3.2 Methane-SIBO
Menschen mit einer Methan-dominanten SIBO leiden meist unter Verstopfung und häufig unter Blähbauch und Blähungen. Methan wird dabei hauptsächlich von Archaeen produziert. Die Bezeichnung SIBO ist hier also eigentlich nicht ganz richtig, da es sich bei Archaeen nicht um Bakterien handelt. Die Methan-dominante-SIBO wird daher IMO (intestinal metanogen overgrowth) (3) genannt. Zusätzlich dazu, dass Archaeen keine klassischen Bakterien sind, können sie sowohl im Dünn- als auch im Dickdarm übersiedeln. Ein wichtiger Aspekt bei der Auswertung der Atemtests.
Archaeen und Bakterien gehören beide zu den Prokaryoten, was bedeutet, dass sie im Gegensatz zu den Eukaryoten keinen Zellkern besitzen. Dennoch unterscheiden sich Archaeen und Bakterien im Zellaufbau und in ihren Stoffwechselprozessen.
Zu den Hauptverursachern einer Methan-dominanten SIBO zählen Methanobrevibacter smithii (4), Methanomassillococcus aund Methanosphaera stadtmaniae.
3.3 Hydrogen-Sulfide-SIBO
In hydrogen sulfide SIBO , bacteria that produce hydrogen sulfide dominate. These include the Fusobacterium genus and Desulfovibrio species. Symptoms may include diarrhea, constipation, bloating (with a characteristic rotten egg smell), and brain fog.
Currently, there is no test in Germany to directly detect hydrogen sulfide in breath. Diagnosis is made through characteristic symptoms, as well as a lactulose breath test conducted over 180 minutes. Since lactulose can only be metabolized by bacteria, an increase in gas levels after 120 minutes indicates bacterial activity in the small intestine. If no increase is observed by 180 minutes, it suggests that hydrogen sulfide-producing bacteria have already metabolized the lactulose in the small intestine.
4. SIBO Therapy
SIBO treatment should be administered by a physician and typically involves specific diets, antibiotics and probiotics. Diagnosiscan be assisted by the SIBO breath test.
References
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- Cresci GA, Bawden E. Gut Microbiome: What We Do and Don’t Know. Nutr Clin Pract. 2015 Dec;30(6):734-46. doi: 10.1177/0884533615609899. Epub 2015 Oct 8. PMID: 26449893; PMCID: PMC4838018.
- Skrzydło-Radomańska B, Cukrowska B. How to Recognize and Treat Small Intestinal Bacterial Overgrowth? J Clin Med. 2022 Oct 12;11(20):6017. doi: 10.3390/jcm11206017. PMID: 36294338; PMCID: PMC9604644.
- Takakura W, Pimentel M. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome – An Update. Front Psychiatry. 2020 Jul 10;11:664. doi: 10.3389/fpsyt.2020.00664. PMID: 32754068; PMCID: PMC7366247.
- Takakura W, Pimentel M. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome – An Update. Front Psychiatry. 2020 Jul 10;11:664. doi: 10.3389/fpsyt.2020.00664. PMID: 32754068; PMCID: PMC7366247.
- Pimentel M, Hosseini A, Chang C, Mathur R, Rashid M, Sedighi R, et al. Fr248 EXHALED HYDROGEN SULFIDE IS INCREASED IN PATIENTS WITH DIARRHEA: RESULTS OF A NOVEL COLLECTION AND BREATH TESTING DEVICE. Gastroenterology. 2021 May;160(6):S-278. DOI: 10.1016/S0016-5085(21)01391-3.
- Guo HZ, Dong WX, Zhang X, Zhu SW, Liu ZJ, Duan LP. [The diagnostic value of hydrogen sulfide breath test for small intestinal bacterial overgrowth]. Zhonghua Nei Ke Za Zhi. 2021 Apr 1;60(4):356-361. Chinese. doi: 10.3760/cma.j.cn112138-20200731-00725. PMID: 33765706.
