检索问题
sibo 有哪些症状
小肠细菌过度生长（SIBO）的主要症状可以归纳为两类：一类是典型的“肚子闹腾”症状，如腹胀、腹痛、腹泻或便秘；另一类是“营养流失”导致的全身性症状，如体重下降、贫血和疲劳。
简单来说，这是一种你的小肠变成了“发酵罐”的疾病，细菌在错误的地方大量繁殖，抢夺你的食物营养，并产生大量气体，从而引发一系列不适 。
以下我将结合科学证据，用通俗易懂的方式为您详细拆解这些症状表现。
1. 核心症状：肚子里的“风暴”
这是最直接、最常见的表现，大约有 33.8% 的胃肠道不适患者最终被检测出患有 SIBO 。
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像吞了气球一样的腹胀（Bloating）与腹部膨隆（Distension） 这是 SIBO 最标志性的症状 。
- 这是什么感觉？ 你可能在吃完饭后不久，感觉肚子像吹气球一样鼓起来，甚至裤腰带都变紧了。这不仅仅是觉得饱，而是一种被气体撑开的压迫感。
- 为什么会这样？ 正常情况下，小肠里的细菌很少。但在 SIBO 患者体内，细菌在小肠里“安营扎寨”。当你吃下去碳水化合物（糖分、淀粉）时，这些细菌比你先抢到食物，开始疯狂“聚餐”。在这个过程中，细菌会发酵食物，产生大量的气体（主要是氢气和甲烷）。小肠空间狭窄，这些凭空多出来的气体无处可去，就会把肚子撑得圆鼓鼓的。
- 科学数据： 这种腹胀非常普遍，但仅仅凭腹胀很难确诊，因为它和很多其他肠胃病太像了 。
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难以捉摸的腹痛与痉挛（Abdominal Pain）
- 表现： 这种痛通常不是剧烈的刺痛，更像是一种钝痛、绞痛或痉挛感 。
- 原因： 主要是肠道里的气体积聚，拉伸了肠壁。加上 SIBO 可能会引起肠道的一种“过敏反应”（医学上叫内脏高敏感性），让你的肠道神经变得格外敏感，一点点气体压力就会让你觉得很疼 。
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厕所习惯的改变：腹泻、便秘或两者交替 SIBO 会彻底扰乱你的排便规律，但具体是跑肚还是便秘，取决于你肚子里哪种细菌占了上风 。
- 腹泻（Diarrhea）： 很多 SIBO 患者会频繁拉肚子 。这是因为细菌分解了胆汁中的盐分（胆盐），导致身体无法正常吸收脂肪。没被吸收的脂肪留在肠道里，会刺激肠壁，还会吸水，导致粪便变得稀烂、油腻。
- 便秘（Constipation）： 如果你体内的“产甲烷古菌”（一种特殊的微生物）比较多，情况就完全相反。这些微生物产生的甲烷气体会像“麻醉剂”一样，麻痹肠道肌肉，让肠道蠕动变慢，导致顽固的便秘。这在医学上甚至有一个专门的名字叫“肠道产甲烷菌过度生长（IMO）” 。
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排气增多（Gas/Flatulence）与打嗝（Belching）
- 既然肚子里是个“产气工厂”，多余的气体总得找出口。于是表现为放屁次数明显增多，或者气往上走导致频繁打嗝 。
2. 全身症状：无声的“营养大盗”
如果是严重的或长期的 SIBO，细菌不仅是在制造气体，它们还会变成“强盗”，偷走本该属于你身体的营养。这会导致一系列看似与肚子无关的全身症状。
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体重莫名下降（Weight Loss）
- 虽然你可能吃得不少，但因为细菌抢走了食物中的能量，或者因为害怕肚子痛而不敢吃东西，导致体重减轻 。甚至在极少数严重情况下，会出现明显的消瘦。
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营养不良与贫血（Malnutrition & Anemia）
- 维生素 B12 缺乏： 细菌非常喜欢吃维生素 B12。如果它们在小肠里把 B12 吃光了，你就会因为缺乏 B12 而感到手脚麻木、记忆力下降，甚至出现巨幼细胞性贫血 。
- 缺铁性贫血： 研究发现，SIBO 与贫血有显著关联 。因为肠道炎症可能会影响铁的吸收。
- 脂溶性维生素缺乏： 由于细菌破坏了胆盐，导致身体很难吸收脂肪，溶解在脂肪里的维生素 A、D、E、K 也跟着流失了 。这可能导致骨质疏松（骨头变脆）、夜盲症等问题。
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食物不耐受（Food Intolerance）
- 你可能会发现自己以前能吃的食物，现在一吃就难受。比如喝牛奶拉肚子（乳糖不耐受），或者吃水果肚子胀（果糖不耐受）。这是因为细菌破坏了小肠壁上的“刷状缘”（这就像小肠表面的一层细绒毛，专门负责消化吸收），导致小肠分泌的消化酶减少，无法处理这些食物 。
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脑雾与疲劳（Fatigue & Brain Fog）
- 虽然主要症状在肠道，但肠道菌群的混乱会通过“肠脑轴”影响大脑。加上身体长期处于轻微的炎症状态和营养吸收不良，很多患者会感到一种挥之不去的疲劳感，或者注意力难以集中 。
3. 需要特别注意的“模仿”现象
SIBO 的症状非常狡猾，它极其容易被误诊。
- 不仅是 IBS（肠易激综合征）： SIBO 和 IBS 的症状几乎一模一样。事实上，研究认为很大一部分被诊断为 IBS 的患者，根源其实就是 SIBO。如果你被诊断为 IBS 但治疗效果不好，可能需要考虑是否存在细菌过度生长 。
- 症状因人而异： 并不是每个人都会有上述所有症状。有的人可能只是觉得稍微有点胀气，有的人可能已经出现了严重的营养不良。这也使得确诊需要依赖呼气测试或小肠液培养等专业手段 。
总结建议
如果你发现自己长期有饭后腹胀、排便习惯改变（腹泻或便秘），并且伴有不明原因的消瘦或贫血，这可能不仅仅是普通的“消化不良”。这些是小肠细菌过度生长（SIBO）的典型警示信号。建议咨询消化科医生，进行氢/甲烷呼气测试来查明真相。
名词解释：
- 小肠与大肠的区别： 想象你的消化道是一座房子。大肠（结肠）是“地下室”，那里本来就住着很多细菌，负责处理垃圾（粪便）。小肠是“客厅”和“厨房”，负责消化吸收营养，这里应该非常干净，细菌很少。SIBO 就是地下室的细菌跑到了客厅里，或者是客厅里自己滋生了脏东西。
- 胆盐（Bile Salts）： 它是肝脏分泌的一种“洗洁精”。就像洗洁精能把油污化开一样，胆盐能把食物中的大块脂肪乳化成小微粒，方便身体吸收。SIBO 的细菌会破坏这种“洗洁精”，导致脂肪无法被消化，最后只能滑肠排出（脂肪泻）。
- 内脏高敏感性（Visceral Hypersensitivity）： 你的肠道神经变得像“惊弓之鸟”。普通人肚子里有点气可能没感觉，但对于内脏高敏感的人，这点气就会被大脑解读为剧烈的疼痛。
References
1Small Intestinal Bacterial Overgrowth: Clinical Features and Therapeutic Management.PubMed
Satish S C Rao, Jigar Bhagatwala
Clin Transl Gastroenterol. 2019 Oct;10(10):e00078. doi: 10.14309/ctg.0000000000000078.
Small intestinal bacterial overgrowth (SIBO) is a common, yet underrecognized, problem. Its prevalence is unknown because SIBO requires diagnostic testing. Although abdominal bloating, gas, distension, and diarrhea are common symptoms, they do not predict positive diagnosis. Predisposing factors include proton-pump inhibitors, opioids, gastric bypass, colectomy, and dysmotility. Small bowel aspirate/culture with growth of 10-10 cfu/mL is generally accepted as the "best diagnostic method," but it is invasive. Glucose or lactulose breath testing is noninvasive but an indirect method that requires further standardization and validation for SIBO. Treatment, usually with antibiotics, aims to provide symptom relief through eradication of bacteria in the small intestine. Limited numbers of controlled studies have shown systemic antibiotics (norfloxacin and metronidazole) to be efficacious. However, 15 studies have shown rifaximin, a nonsystemic antibiotic, to be effective against SIBO and well tolerated. Through improved awareness and scientific rigor, the SIBO landscape is poised for transformation.
2[Small intestinal bacterial overgrowth (SIBO) - Therapy, nutrition, microbiome].PubMed
Gernot Sellge, Johann Ockenga
Dtsch Med Wochenschr. 2024 Sep;149(18):1071-1079. doi: 10.1055/a-2205-5794. Epub 2024 Aug 29.
SIBO (small intestinal bacterial overgrowth) is defined by bacterial overgrowth or colonization of the small intestine in combination with gastrointestinal symptoms such as bloating, nausea, pain, diarrhoea, malabsorption and food intolerance. SIBO can be caused by various mechanisms such as reduced intestinal motility, altered gastrointestinal anatomy, reduced gastric acid or pancreatic enzyme production, altered bile acid metabolism, or immune defects. Accordingly, SIBO often develops secondary to different underlying diseases.Diet has a fundamental influence on the composition of the intestinal microbiome and is therefore also a potential pathomechanism in SIBO. Furthermore, food intolerances are common in SIBO patients. However, both aspects have so far been insufficiently investigated. Nevertheless, elemental diets, carbohydrate-reduced diets, as well as pre- and probiotics are potential therapy options.This article provides a summary of current knowledge on the pathophysiology, diagnosis and treatment of SIBO, with particular emphasis on the role of nutrition and the microbiome.
3Small intestinal bacterial overgrowth: current update.PubMed
Hammad Zafar, Brenda Jimenez, Alison Schneider
Curr Opin Gastroenterol. 2023 Nov 1;39(6):522-528. doi: 10.1097/MOG.0000000000000971. Epub 2023 Sep 18.
PURPOSE OF REVIEW: This article aims to provide an up-to-date review of small intestinal bacterial overgrowth (SIBO), including etiology and risk factors, clinical manifestations, diagnostic evaluation for suspected SIBO, and therapeutic options. RECENT FINDINGS: Recent advances in breath testing, capsule and urine-based testing have opened new avenues and improved diagnostic yield of SIBO. Nonantibiotic-based treatment strategies have shown promising results in initial trials. SUMMARY: Small intestinal bacterial overgrowth (SIBO) is a condition defined by the excess bacteria or changes in bacterial composition of the small intestine. These are associated with various gastrointestinal (GI) symptoms such as bloating, abdominal distension, diarrhea, nutrient deficiencies, and even frank weight loss. Small bowel jejunal aspirate of >10 5 CFU/ml has traditionally been considered the gold standard for diagnosis. Glucose and lactulose breath testing have become more common in clinical practice as they are noninvasive, easily accessible, and have lower cost. Treatment focuses on the eradication of excess bacteria in the small bowel and is traditionally done with the use of oral antibiotics. Other emerging therapies may include probiotics, diet manipulation, and prokinetic agents.
4Epidemiology of small intestinal bacterial overgrowth.PubMed
Irina Efremova, Roman Maslennikov, Elena Poluektova, et al.
World J Gastroenterol. 2023 Jun 14;29(22):3400-3421. doi: 10.3748/wjg.v29.i22.3400.
Small intestinal bacterial overgrowth (SIBO) is defined as an increase in the bacterial content of the small intestine above normal values. The presence of SIBO is detected in 33.8% of patients with gastroenterological complaints who underwent a breath test, and is significantly associated with smoking, bloating, abdominal pain, and anemia. Proton pump inhibitor therapy is a significant risk factor for SIBO. The risk of SIBO increases with age and does not depend on gender or race. SIBO complicates the course of a number of diseases and may be of pathogenetic significance in the development of their symptoms. SIBO is significantly associated with functional dyspepsia, irritable bowel syndrome, functional abdominal bloating, functional constipation, functional diarrhea, short bowel syndrome, chronic intestinal pseudo-obstruction, lactase deficiency, diverticular and celiac diseases, ulcerative colitis, Crohn's disease, cirrhosis, metabolic-associated fatty liver disease (MAFLD), primary biliary cholangitis, gastroparesis, pancreatitis, cystic fibrosis, gallstone disease, diabetes, hypothyroidism, hyperlipidemia, acromegaly, multiple sclerosis, autism, Parkinson's disease, systemic sclerosis, spondylarthropathy, fibromyalgia, asthma, heart failure, and other diseases. The development of SIBO is often associated with a slowdown in orocecal transit time that decreases the normal clearance of bacteria from the small intestine. The slowdown of this transit may be due to motor dysfunction of the intestine in diseases of the gut, autonomic diabetic polyneuropathy, and portal hypertension, or a decrease in the motor-stimulating influence of thyroid hormones. In a number of diseases, including cirrhosis, MAFLD, diabetes, and pancreatitis, an association was found between disease severity and the presence of SIBO. Further work on the effect of SIBO eradication on the condition and prognosis of patients with various diseases is required.
5Small Intestinal Bacterial Overgrowth-Pathophysiology and Its Implications for Definition and Management.PubMed
Daniel Bushyhead, Eamonn M M Quigley
Gastroenterology. 2022 Sep;163(3):593-607. doi: 10.1053/j.gastro.2022.04.002. Epub 2022 Apr 7.
The concept of small intestinal bacterial overgrowth (SIBO) arose in the context of maldigestion and malabsorption among patients with obvious risk factors that permitted the small bowel to be colonized by potentially injurious colonic microbiota. Such colonization resulted in clinical signs, symptoms, and laboratory abnormalities that were explicable within a coherent pathophysiological framework. Coincident with advances in medical science, diagnostic testing evolved from small bowel culture to breath tests and on to next-generation, culture-independent microbial analytics. The advent and ready availability of breath tests generated a dramatic expansion in both the rate of diagnosis of SIBO and the range of associated gastrointestinal and nongastrointestinal clinical scenarios. However, issues with the specificity of these same breath tests have clouded their interpretation and aroused some skepticism regarding the role of SIBO in this expanded clinical repertoire. Furthermore, the pathophysiological plausibility that underpins SIBO as a cause of maldigestion/malabsorption is lacking in regard to its purported role in irritable bowel syndrome, for example. One hopes that the application of an ever-expanding armamentarium of modern molecular microbiology to the human small intestinal microbiome in both health and disease will ultimately resolve this impasse and provide an objective basis for the diagnosis of SIBO.
6Diet and intestinal bacterial overgrowth: Is there evidence?PubMed
Claudineia Souza, Raquel Rocha, Helma Pinchemel Cotrim
World J Clin Cases. 2022 May 26;10(15):4713-4716. doi: 10.12998/wjcc.v10.i15.4713.
The intestinal microbiota and its role in health and disease processes have been the subject of several studies. It is known that changes in the intestinal microbiota occur due to several factors, such as the use of medication, age, lifestyle and diseases, which can modify intestinal homeostasis and lead to excessive growth of bacteria in the small intestine, triggering a clinical condition called small bowel bacterial overgrowth (SIBO). Individuals with SIBO may present gastrointestinal symptoms ranging from nausea, diarrhea and/or constipation, and flatulence to distension and abdominal pain, resulting from poor absorption of nutrients or changes in intestinal permeability. The gold-standard treatment is based on the use of antibiotics to eradicate bacterial overgrowth. Some studies have evaluated diets in the treatment of SIBO; however, the studies are of low methodological quality, making extrapolation of the results to clinical practice unfeasible. Thus, there is still not enough scientific evidence to support a specific type of diet for the treatment of SIBO.
7Small Intestinal Bacterial and Fungal Overgrowth: Health Implications and Management Perspectives.PubMed
Natalie Soliman, Caroline Kruithoff, Erin Marie San Valentin, et al.
Nutrients. 2025 Apr 17;17(8):1365. doi: 10.3390/nu17081365.
BACKGROUND/OBJECTIVES: Small Intestinal Bacterial Overgrowth (SIBO) and Small Intestinal Fungal Overgrowth (SIFO) are distinct yet often overlapping conditions characterized by an abnormal increase in microbial populations within the small intestine. SIBO results from an overgrowth of colonic bacteria, while SIFO is driven by fungal overgrowth, primarily involving species. Both conditions present with nonspecific gastrointestinal (GI) symptoms such as bloating, abdominal pain, diarrhea, and malabsorption, making differentiation between SIBO and SIFO challenging. This review aims to elucidate the underlying mechanisms, risk factors, diagnostic challenges, and management strategies associated with SIBO and SIFO. METHODS: A comprehensive review of current literature was conducted, focusing on the pathophysiology, diagnostic modalities, and therapeutic approaches for SIBO and SIFO. RESULTS: SIBO is commonly associated with factors such as reduced gastric acid secretion, impaired gut motility, and structural abnormalities like bowel obstruction and diverticula. It is frequently diagnosed using jejunal aspirates (≥10 colony forming units (CFUs)/mL) or breath tests. In contrast, SIFO is linked to prolonged antibiotic use, immunosuppression, and gut microbiome dysbiosis, with diagnosis relying on fungal cultures from small intestinal aspirates due to the absence of standardized protocols. CONCLUSION: The clinical overlap and frequent misdiagnosis of SIBO and SIFO highlight the need for improved diagnostic tools and a multidisciplinary approach to management. This review emphasizes the importance of understanding the mechanisms behind SIBO and SIFO, how they relate to other health outcomes, and potential management strategies to optimize patient care and therapeutic outcomes.
8Small Intestinal Bacterial Overgrowth: Nutritional Implications, Diagnosis, and Management.PubMed
Abimbola Adike, John K DiBaise
Gastroenterol Clin North Am. 2018 Mar;47(1):193-208. doi: 10.1016/j.gtc.2017.09.008. Epub 2017 Dec 7.
Small intestinal bacterial overgrowth (SIBO), characterized by the presence of excessive bacteria in the small intestine, is typically described as a malabsorptive syndrome occurring in the context of gut stasis syndromes. SIBO is now considered to be a disorder associated with diverse clinical conditions without classic risk factors for SIBO and a cause of several nonspecific gastrointestinal and nongastrointestinal symptoms. Because there is currently no gold standard for diagnosing SIBO, its prevalence and role in the pathogenesis of other diseases remain uncertain; as does optimal treatment of patients with relapsing symptoms.
9How to Recognize and Treat Small Intestinal Bacterial Overgrowth?PubMed
Barbara Skrzydło-Radomańska, Bożena Cukrowska
J Clin Med. 2022 Oct 12;11(20):6017. doi: 10.3390/jcm11206017.
Small Intestinal Bacterial Overgrowth (SIBO) is a form of dysbiosis that involves increased bacterial colonization of the small intestine with some of the bacteria more characteristic of the colon microbiota. The prevalence of SIBO over recent decades has been estimated to range from 2.5 to 22% (depending on the source) and to increase with age and among individuals with comorbidities. Recently, an increase in the number of diagnosed SIBO cases has been observed, which is primarily due to the availability of noninvasive breath tests that facilitate the diagnostic process. However, SIBO is still both a diagnostic and a therapeutic problem. This review presents the pathophysiology, manifestations, diagnostics, and recommended management of SIBO.
10Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome - An Update.PubMed
Will Takakura, Mark Pimentel
Front Psychiatry. 2020 Jul 10;11:664. doi: 10.3389/fpsyt.2020.00664. eCollection 2020.
Small intestinal bacterial overgrowth (SIBO) is one manifestation of gut microbiome dysbiosis and is highly prevalent in IBS (Irritable Bowel Syndrome). SIBO can be diagnosed either by a small bowel aspirate culture showing ≥10 colony-forming units (CFU) per mL of aspirate, or a positive hydrogen lactulose or glucose breath test. Numerous pathogenic organisms have been shown to be increased in subjects with SIBO and IBS, including but not limited to , and In addition, , the causal organism in a positive methane breath test, has been linked to constipation predominant irritable bowel syndrome (IBS-C). As is an archaeon and can overgrow in areas outside of the small intestine, it was recently proposed that the term intestinal methanogen overgrowth (IMO) is more appropriate for the overgrowth of these organisms. Due to gut microbiome dysbiosis, patients with IBS may have increased intestinal permeability, dysmotility, chronic inflammation, autoimmunity, decreased absorption of bile salts, and even altered enteral and central neuronal activity. As a consequence, SIBO and IBS share a myriad of symptoms including abdominal pain, distention, diarrhea, and bloating. Furthermore, gut microbiome dysbiosis may be associated with select neuropsychological symptoms, although more research is needed to confirm this connection. This review will focus on the role of the gut microbiome and SIBO in IBS, as well as novel innovations that may help better characterize intestinal overgrowth and microbial dysbiosis.
11Small intestinal microbial dysbiosis underlies symptoms associated with functional gastrointestinal disorders.PubMed
George B Saffouri, Robin R Shields-Cutler, Jun Chen, et al.
Nat Commun. 2019 May 1;10(1):2012. doi: 10.1038/s41467-019-09964-7.
Small intestinal bacterial overgrowth (SIBO) has been implicated in symptoms associated with functional gastrointestinal disorders (FGIDs), though mechanisms remain poorly defined and treatment involves non-specific antibiotics. Here we show that SIBO based on duodenal aspirate culture reflects an overgrowth of anaerobes, does not correspond with patient symptoms, and may be a result of dietary preferences. Small intestinal microbial composition, on the other hand, is significantly altered in symptomatic patients and does not correspond with aspirate culture results. In a pilot interventional study we found that switching from a high fiber diet to a low fiber, high simple sugar diet triggered FGID-related symptoms and decreased small intestinal microbial diversity while increasing small intestinal permeability. Our findings demonstrate that characterizing small intestinal microbiomes in patients with gastrointestinal symptoms may allow a more targeted antibacterial or a diet-based approach to treatment.
12How to Test and Treat Small Intestinal Bacterial Overgrowth: an Evidence-Based Approach.PubMed
Ali Rezaie, Mark Pimentel, Satish S Rao
Curr Gastroenterol Rep. 2016 Feb;18(2):8. doi: 10.1007/s11894-015-0482-9.
Small intestinal bacterial overgrowth (SIBO) is characterized by an excessive amount of bacteria in the small intestine and a constellation of symptoms that include bloating, pain, gas, and diarrhea. Although known for many decades, there is a lack of consensus and clarity regarding the natural history and methods for its diagnosis. Several tests have been proposed, including the glucose breath test, lactulose breath test, small intestinal aspiration and culture, and others. However, there is a lack of standardization of these tests and their interpretation. Treatment of SIBO remains empirical; generally, broad spectrum antibiotics are recommended for 2 weeks (amoxicillin, rifaximin, ciprofloxacin, etc.) but evidence for their use is fair. Clearly, there is a strong need to develop a systematic approach for the management of SIBO and to perform multicenter clinical trials for the treatment of SIBO. In this review, we will discuss the current evidence for the diagnosis and treatment of SIBO, which includes (1) elimination/modification of the underlying causes, (2) induction of remission (antibiotics and elemental diet), and (3) maintenance of remission (promotility drugs, dietary modifications, repeat or cyclical antibiotics).
13Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy.PubMed
Uday C Ghoshal, Ratnakar Shukla, Ujjala Ghoshal
Gut Liver. 2017 Mar 15;11(2):196-208. doi: 10.5009/gnl16126.
The pathogenesis of irritable bowel syndrome (IBS), once thought to be largely psychogenic in origin, is now understood to be multifactorial. One of the reasons for this paradigm shift is the realization that gut dysbiosis, including small intestinal bacterial overgrowth (SIBO), causes IBS symptoms. Between 4% and 78% of patients with IBS and 1% and 40% of controls have SIBO; such wide variations in prevalence might result from population differences, IBS diagnostic criteria, and, most importantly, methods to diagnose SIBO. Although quantitative jejunal aspirate culture is considered the gold standard for the diagnosis of SIBO, noninvasive hydrogen breath tests have been popular. Although the glucose hydrogen breath test is highly specific, its sensitivity is low; in contrast, the early-peak criteria in the lactulose hydrogen breath test are highly nonspecific. Female gender, older age, diarrhea-predominant IBS, bloating and flatulence, proton pump inhibitor and narcotic intake, and low hemoglobin are associated with SIBO among IBS patients. Several therapeutic trials targeting gut microbes using antibiotics and probiotics have further demonstrated that not all symptoms in patients with IBS originate in the brain but rather in the gut, providing support for the micro-organic basis of IBS. A recent proof-of-concept study showing the high frequency of symptom improvement in patients with IBS with SIBO further supports this hypothesis.
14Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods.PubMed
Ted George O Achufusi, Anuj Sharma, Ernesto A Zamora, et al.
Cureus. 2020 Jun 27;12(6):e8860. doi: 10.7759/cureus.8860.
Small intestinal bacterial overgrowth (SIBO) is a commonly diagnosed gastrointestinal disorder affecting millions of individuals throughout the United States. It refers to a condition in which there is an excess and imbalance of small intestinal bacteria. Despite its prevalence, it remains underdiagnosed due to the invasive nature of diagnostic testing. Symptoms observed in SIBO, including abdominal distension, bloating, diarrhea, and gas formation, are nonspecific and can overlap with other gastrointestinal disorders. Frequently cited predisposing factors include gastric acid suppression, dysmotility, gastric bypass, and opioids. The diagnostic gold standard remains small bowel aspirate and culture. However, due to its invasive nature, it remains an unpopular method among patients and clinicians alike. Glucose and lactulose breath testing have become the go-to diagnostic method in clinical practice due to its noninvasive nature and low cost. Treatment is guided towards the eradication of bacteria in the small bowel and usually consists of a prolonged course of oral antibiotics. Due to recent advances in our understanding of the human microbiome, we are surely poised for a transformation in our approach to diagnosing and treating this condition.
15Small intestinal bacterial overgrowth syndrome.PubMed
Jan Bures, Jiri Cyrany, Darina Kohoutova, et al.
World J Gastroenterol. 2010 Jun 28;16(24):2978-90. doi: 10.3748/wjg.v16.i24.2978.
Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO.
16Short bowel syndrome: Complications and management.PubMed
Jamie Bering, John K DiBaise
Nutr Clin Pract. 2023 May;38 Suppl 1:S46-S58. doi: 10.1002/ncp.10978.
Short bowel syndrome (SBS) occurs when a patient loses bowel length or function significantly enough to cause malabsorption, oftentimes requiring lifelong parenteral support. In adults, this occurs most commonly in the setting of massive intestinal resection, whereas congenital anomalies and necrotizing enterocolitis predominate in children. Many patients with SBS develop long-term clinical complications over time related to their altered intestinal anatomy and physiology or to various treatment interventions such as parenteral nutrition and the central venous catheter through which it is administered. Identifying, preventing, and treating these complications can be challenging. This review will focus on the diagnosis, treatment, and prevention of several complications that can occur in this patient population, including diarrhea, fluid and electrolyte imbalance, vitamin and trace element derangements, metabolic bone disease, biliary disorders, small intestinal bacterial overgrowth, d-lactic acidosis, and complications of central venous catheters.
17AGA Clinical Practice Update on Evaluation and Management of Belching, Abdominal Bloating, and Distention: Expert Review.PubMed
Baha Moshiree, Douglas Drossman, Aasma Shaukat
Gastroenterology. 2023 Sep;165(3):791-800.e3. doi: 10.1053/j.gastro.2023.04.039. Epub 2023 Jul 13.
DESCRIPTION: Belching, bloating, and abdominal distention are all highly prevalent gastrointestinal symptoms and account for some of the most common reasons for patient visits to outpatient gastroenterology practices. These symptoms are often debilitating, affecting patients' quality of life, and contributing to work absenteeism. Belching and bloating differ in their pathophysiology, diagnosis, and management, and there is limited evidence available for their various treatments. Therefore, the purpose of this American Gastroenterological Association (AGA) Clinical Practice Update is to provide best practice advice based on both controlled trials and observational data for clinicians covering clinical features, diagnostics, and management considerations that include dietary, gut-directed behavioral, and drug therapies. METHODS: This Expert Review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. These best practice advice statements were drawn from a review of the published literature based on clinical trials, the more robust observational studies, and from expert opinion. Because systematic reviews were not performed, these best practice advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: Clinical history and physical examination findings and impedance pH monitoring can help to differentiate between gastric and supragastric belching. BEST PRACTICE ADVICE 2: Treatment options for supragastric belching may include brain-gut behavioral therapies, either separately or in combination, such as cognitive behavioral therapy, diaphragmatic breathing, speech therapy, and central neuromodulators. BEST PRACTICE ADVICE 3: Rome IV criteria should be used to diagnose primary abdominal bloating and distention. BEST PRACTICE ADVICE 4: Carbohydrate enzyme deficiencies may be ruled out with dietary restriction and/or breath testing. In a small subset of at-risk patients, small bowel aspiration and glucose- or lactulose-based hydrogen breath testing may be used to evaluate for small intestinal bacterial overgrowth. BEST PRACTICE ADVICE 5: Serologic testing may rule out celiac disease in patients with bloating and, if serologies are positive, a small bowel biopsy should be done to confirm the diagnosis. A gastroenterology dietitian should be part of the multidisciplinary approach to care for patients with celiac disease and nonceliac gluten sensitivity. BEST PRACTICE ADVICE 6: Abdominal imaging and upper endoscopy should be ordered in patients with alarm features, recent worsening symptoms, or an abnormal physical examination only. BEST PRACTICE ADVICE 7: Gastric emptying studies should not be ordered routinely for bloating and distention, but may be considered if nausea and vomiting are present. Whole gut motility and radiopaque transit studies should not be ordered unless other additional and treatment-refractory lower gastrointestinal symptoms exist to warrant testing for neuromyopathic disorders. BEST PRACTICE ADVICE 8: In patients with abdominal bloating and distention thought to be related to constipation or difficult evacuation, anorectal physiology testing is suggested to rule out a pelvic floor disorder. BEST PRACTICE ADVICE 9: When dietary modifications are needed (eg, low-fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet), a gastroenterology dietitian should preferably monitor treatment. BEST PRACTICE ADVICE 10: Probiotics should not be used to treat abdominal bloating and distention. BEST PRACTICE ADVICE 11: Biofeedback therapy may be effective for bloating and distention when a pelvic floor disorder is identified. BEST PRACTICE ADVICE 12: Central neuromodulators (eg, antidepressants) are used to treat bloating and abdominal distention by reducing visceral hypersensitivity, raising sensation threshold, and improving psychological comorbidities. BEST PRACTICE ADVICE 13: Medications used to treat constipation should be considered for treating bloating if constipation symptoms are present. BEST PRACTICE ADVICE 14: Psychological therapies, such as hypnotherapy, cognitive behavioral therapy, and other brain-gut behavior therapies may be used to treat patients with bloating and distention. BEST PRACTICE 15: Diaphragmatic breathing and central neuromodulators are used to treat abdominophrenic dyssynergia.
18A Comprehensive Review of the Usefulness of Prebiotics, Probiotics, and Postbiotics in the Diagnosis and Treatment of Small Intestine Bacterial Overgrowth.PubMed
Adrian Martyniak, Magdalena Wójcicka, Iwona Rogatko, et al.
Microorganisms. 2025 Jan 1;13(1):57. doi: 10.3390/microorganisms13010057.
Small intestinal bacterial overgrowth (SIBO) is a disorder characterized by the excessive growth of bacteria in the small intestine. Bacterial overgrowth disrupts the bacterial balance and can lead to abdominal pain, weight loss, and gastrointestinal symptoms, including bloating, diarrhea, and malabsorption. SIBO is widespread in the population. There are two main methods for diagnosing SIBO: breath tests and bacterial culture. The most commonly used method is a breath test, which enables the division of SIBO into the following three types: hydrogen-dominant (H-SIBO), methane-dominant (CH-SIBO), and hydrogen/methane-dominant (H/CH-SIBO). This comprehensive review aims to present the current knowledge on the use of prebiotics, probiotics, and postbiotics in the context of SIBO. For this purpose, medical databases such as MEDLINE (PubMed) and Scopus were analyzed using specific keywords and their combinations. This review is based on research studies no older than 10 years old and those using only human models. In summary, clinical studies have shown that the efficacy of SIBO therapy can be increased by combining antibiotics with probiotics, especially in vulnerable patients such as children and pregnant women. The further development of diagnostic methods, such as point of care testing (POCT) and portable devices, and a better understanding of the mechanisms of biotics action are needed to treat SIBO more effectively and improve the quality of life of patients.
19DIAGNOSIS AND TREATMENT OF SMALL INTESTINAL BACTERIAL OVERGROWTH: AN OFFICIAL POSITION PAPER FROM THE BRAZILIAN FEDERATION OF GASTROENTEROLOGY.PubMed
Bruno César da Silva, Gabriela Piovezani Ramos, Luisa Leite Barros, et al.
Arq Gastroenterol. 2025 Feb 17;62:e24107. doi: 10.1590/S0004-2803.24612024-107. eCollection 2025.
BACKGROUND: Small intestinal bacterial overgrowth (SIBO) is a condition characterized by an abnormal increase in bacterial population in the small intestine, leading to symptoms such as bloating, abdominal pain, distension, diarrhea, and eventually malabsorption. The diagnosis and management of SIBO remain challenging due to overlapping symptoms with other gastrointestinal disorders such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and coeliac disease. OBJECTIVE: This article aims to review current evidence on the diagnosis and treatment of SIBO, with a focus on strategies suitable for the Brazilian healthcare system. METHODS: A comprehensive literature review was performed, focusing on clinical guidelines, randomized controlled trials, and cohort studies concerning SIBO. Diagnostic methods, including breath tests and direct aspiration techniques, were critically analyzed. Treatment approaches, including antibiotics, dietary modifications, and probiotics, were reviewed. The recommendations were formulated based on a panel of gastroenterologists, members of the Brazilian Federation of Gastroenterology (FBG), with approval from the majority of the members. RESULTS: Breath tests using glucose and lactulose remain the most commonly used non-invasive diagnostic tools, though they are subject to limitations such as false positives and false negatives. Treatment with rifaximin is effective in most cases of SIBO, while systemic antibiotics like metronidazole and ciprofloxacin are alternatives. Probiotics and dietary interventions, particularly low FODMAP diets, can complement antibiotic therapy. Long-term follow-up is essential due to the recurrence rate, which is common in SIBO patients. CONCLUSION: Standardizing SIBO diagnosis and treatment in Brazil is essential to reduce diagnostic delays and optimize care, especially given the disparities and heterogeneity in clinical practice across the country. This article provides evidence-based recommendations to guide clinical practice. Further research is needed to refine diagnostic methods, explore novel treatment strategies, and better understand the specific characteristics of the Brazilian population.
20Show Me What You Have Inside-The Complex Interplay between SIBO and Multiple Medical Conditions-A Systematic Review.PubMed
Natalia Sroka, Alicja Rydzewska-Rosołowska, Katarzyna Kakareko, et al.
Nutrients. 2022 Dec 24;15(1):90. doi: 10.3390/nu15010090.
The microbiota, as a complex of microorganisms in a particular ecosystem, is part of the wider term-microbiome, which is defined as the set of all genetic content in the microbial community. Imbalanced gut microbiota has a great impact on the homeostasis of the organism. Dysbiosis, as a disturbance in bacterial balance, might trigger or exacerbate the course of different pathologies. Small intestinal bacterial overgrowth (SIBO) is a disorder characterized by differences in quantity, quality, and location of the small intestine microbiota. SIBO underlies symptoms associated with functional gastrointestinal disorders (FGD) as well as may alter the presentation of chronic diseases such as heart failure, diabetes, etc. In recent years there has been growing interest in the influence of SIBO and its impact on the whole human body as well as individual systems. Therefore, we aimed to investigate the co-existence of SIBO with different medical conditions. The PubMed database was searched up to July 2022 and we found 580 original studies; inclusion and exclusion criteria let us identify 112 eligible articles, which are quoted in this paper. The present SIBO diagnostic methods could be divided into two groups-invasive, the gold standard-small intestine aspirate culture, and non-invasive, breath tests (BT). Over the years scientists have explored SIBO and its associations with other diseases. Its role has been confirmed not only in gastroenterology but also in cardiology, endocrinology, neurology, rheumatology, and nephrology. Antibiotic therapy could reduce SIBO occurrence resulting not only in the relief of FGD symptoms but also manifestations of comorbid diseases. Although more research is needed, the link between SIBO and other diseases is an important pathway for scientists to follow.