小肠细菌过度生长的定义
小肠细菌过度生长（SIBO）是一种以小肠细菌过多为特征的消化系统疾病。根据不同的检查方法有不同的定义方法。最早的期的方法是吸取近端空肠的小肠液做细菌培养。当每毫升近端空肠抽吸液达到或超过10的5次方个菌落形成单位（CFU）即定义为小肠细菌过度生长。
用甲烷和氢呼气实验检测细菌代谢产物的方法，在小肠段氢气上升值超过空腹基础值20ppm，或者甲烷超过空腹基础值12ppm，或者氢和甲烷的上升值超过二者基础值之和15pp
m，即可定义为小肠细菌过度生长。
最常见的过度生长的细菌是共生厌氧菌——类杆菌39%、乳酸杆菌25%、梭状芽孢杆菌20%和共生需氧链球菌60%、大肠杆菌36%、葡萄球菌ococcus 13%，klebsiella 11%。35最近的一项研究发现，需氧菌为大肠杆菌37%，肠球菌spp 32%，klebsiella肺炎24%，奇异变形杆菌6.5%。
从以下一些关于小肠细菌过度生长的定义或解释，有助于我们了解什么是小肠细菌过度生长。
1、在百度百科和互动百科给出相同的定义：小肠细菌过度生长(enteric bacterial overgrowth syndrome，EBOS)主要因为小肠淤滞，细菌在小肠过度繁殖从而造成吸收不良。临床上出现腹泻、脂肪泻、贫血和营养吸收障碍等表现，用适当抗生素治疗有良好效果。因此又称为小肠淤积综合征、小肠污染综合征或盲襻综合征。
2、在eMedicineHealth网站给出以 下定义: SIBO is a condition in which colonic-type bacteria (rembling bacteria normally found in the colon) proliferate in large numbers in the small intestine.
小肠细菌过度生长是一种结肠型细菌（类似于结肠中常见的细菌）在小肠大量增殖的疾病。
3、在Web Med网站给出以下定义：Small intestinal bacterial overgrowth (SIBO) is also known as small bowel bacterial overgrowth syndrome (SBBOS). Small intestinal bacterial overgrowth (SIBO) refers to a condition in which abnormally large numbers of bacteria are prent in the small intestine, while the types of bacteria found in the small intestine are more like the bacteria found in the colon.
小肠细菌过度生长（SIBO）也称为小肠细菌过度生长综合征（SBBO）。小肠细菌过度生长（SIBO）是指小肠内出现异常大量细菌，而小肠内发现的细菌类型更像结肠内发现的细菌。
4、在The Free Dictionay给出以下定义: small intestinal bacterial overgrowth is the “Excessive concentrations of colonic bacteria (exceeding 100,000 microorganisms per mL) within the duodenum or jejunum. SIBO may produce abdominal pain, bloating, and diarrhea owing to malabsorption. Synonym: small bowel bacterial overgrowth”. A conditio
n characterid by naua, vomiting, bloating, flatulence, diarrhoea, and steatorrhoea linked to a relative increa in bacteria in GI content which over time may be result in malnutrition. Diagnosis Jejunum aspirate with > 105 bacteria/ml. Risk factors Proton pump inhibitors, anatomic defects—e.g., fistulas, diverticula, blind loops, rection of ileo-cecal valve，Management Antibiotics, given in short cycles to prevent resistance.
小肠细菌过度生长是指“十二指肠或空肠内的结肠细菌浓度过高（超过每毫升100,000个微生物）。由于吸收不良，SIBO可能导致腹痛、腹胀和腹泻。同义词：小肠细菌过度生长”。一种以恶心、呕吐、腹胀、胀气、腹泻和脂肪酸为特征的疾病，与胃肠内细菌含量的相对增加有关，随着时间的推移，这可能导致营养不良。诊断空肠吸引液中细菌数>105/ml。危险因素有质子泵抑制剂，解剖缺陷，如瘘管、憩室、盲环、回肠盲肠瓣切除、抗生素治疗，短周期服用以防止抵抗。
5、Jan Bures, et al.,Small intestinal bacterial overgrowth syndrome. (World J Gastroenterol. 2010 Jun 28; 16(24): 2978–2990).的定义是：Small intestinal bacterial overgrowth (SIBO) is an intestinal microflora unbalance, which can show a wide clinical s
pectrum ranging from a mild and unspecific intestinal symptoms to a vere malabsorption syndrome. The culture of jejunal aspirate is considered the gold standard diagnostic test for SIBO, however, gluco and lactulo breath tests (GBT and LBT) are currently ud in clinical practice. Among them, GBT ems to have a higher diagnostic accuracy in studies comparing breath tests versus culture. Some conditions, such as hypo-aclorhydria, anatomical abnormalities or gastrointestinal motility failure, may cau SIBO and related malabsorption. In the cas, GBT may be uful in order to establish whether malabsorption is due to SIBO or to the underlying dia.
小肠细菌过度生长（SIBO）是一种肠道菌群失衡现象，其临床表现范围广泛，从轻微和非特异性的肠道症状到严重的吸收不良综合征。空肠吸引液培养被认为是SIBO的金标准诊断试验，而葡萄糖和乳果糖 呼气实验（GBT和LBT）目前已在临床实践中应用。其中，在比较呼吸测试与培养的研究中，GBT似乎具有更高的诊断准确性。某些情况，如低二氧化碳、解剖异常或胃肠动力衰竭，可能导致SIBO和相关的吸收不良。在这些情况下，GBT可用于确定吸收不良是由SIBO引起还是由潜在疾病引起。
6、在《胃肠道疾病的H2呼气测试的方法和指标：罗马共识会议》的定义是：SIBO is defined as an increa in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are veral endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid cretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal cretion and bacteriostatic properties of pancreatic and biliary cretion.
SIBO是指上消化道细菌数量的增加和/或类型的改变。有几种预防细菌过度生长的内源性防御机制：胃酸分泌、肠道运动、完整的回肠-盲肠瓣膜、肠道分泌中的免疫球蛋白以及胰腺和胆汁分泌的抑菌特性。
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 rections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, smal
l intestinal pudo-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 ud for the diagnosis of SIBO using gluco or lactulo. Therapy for SIBO must be complex, addressing all caus, symptoms and complications, and fully individualid. It should include treatment of the underlying dia, nutritional support and cyclical gastro-intestinal lective antibiotics. Prognosis is usually rious, determined mostly by the underlying dia that led to SIBO.
SIBO的病因通常是复杂的，与保护性抗菌机制紊乱（如：失氢症、胰腺外分泌功能不全、免疫缺陷综合征）、解剖异常（如小肠梗阻、憩室、瘘管、手术盲环、以前的回肠-盲肠切除术）和/或胃肠运动障碍有关（例如硬皮病、糖尿病的自主神经病变、放射后肠病、小肠假性梗阻）。在某些患者中，可能涉及多个因素。与SIBO相关的症状包括腹胀、腹泻、吸收不良、体重减轻和营养不良。诊断SIBO的金标准仍然是空肠抽吸物的微生物检查。无创氢气和甲烷呼吸试验最常用于使用葡萄糖或乳果糖诊断SIBO。SIBO治疗必须复杂，解决
所有原因、症状和并发症，并完全个性化。它应该包括对潜在疾病的治疗、营养支持和周期性胃肠选择性抗生素。预后通常很严重，主要由导致SIBO的潜在疾病决定。
