胃食管反流病（GERD）患者多伴有其它功能性胃肠病症状。特别是与肠易激综合征（IBS）和小肠细菌过度生长（SIBO）的症状存在高度的重叠性。胃食管反流病患者中小肠细菌过度生长的发病率明显高于对照组，反之，小肠细菌过度生长患者中胃食管反流病的发病率也明显高于对照组。小肠细菌过度生长的一个明显特点是在小肠过度增生的细菌酵解碳水化合物产生氢气和二氧化碳，在有产甲烷菌存在的情况下还会产生甲烷。过量的气体会通过三种机制导致胃食管反流：1.导致腹胀和腹内压增加，压迫胃内容物逆行进入食管；2.部分气体在压力作用下上行，通过胃和食管溢出；3.引起反射性下食管括约肌松弛。了解胃食管反流病和小肠细菌过度生长的关系有助于为寻找胃食管反流病的致病原因，制定合理的治疗胃食管反流病提供新的方向。

Patients with gastroesophageal reflux disease (GERD) are often accompanied by otherfunctional gastrointestinal symptoms. In particular, there is a high percentage overlapwith the symptoms of irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO). The GERD patients have a significant higher prevalence of SIBO than control group. While, the SIBO patients have a significant higher prevalence GERD than control group also. An obvious feature of SIBO is that the hydrogen and carbon dioxide were produced by overgrown bacteria ferment carbohydrate in small intestine, and may produce methane in the presence of methanogens. Excessive gas can cause gastroesophageal reflux through three mechanisms: 1. abdominal distension and increased intra-abdominal pressure, compression of gastric contents retrograde into the esophagus; 2. part of the gas under the pressure upward through the stomach and esophagus; 3. relax esophageal sphincter by reflex. Understanding the relationship between GERD and SIBO is helpful to find out the underline cause of GERD and provide a new direction for the rational GERD treatment.