Institute of Infection, Immunity and Inflammation and the Centre for Biomolecular Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
World J Gastroenterol. 2010 Jul 14;16(26):3226-34. doi: 10.3748/wjg.v16.i26.3226.
The Middle East is the home of ethnic groups from three main backgrounds: Semitic (Arabs and Jews), Indo-European (Persians and Kurdish) and Turkic (Turkish and Turkmens). Its geographic location, which has been under continuous influences from Asia, Europe and Africa, has made it an ideal site for epidemiological studies on Helicobacter pylori (H. pylori) infection and genotyping. The gastric cancer rate differs in this region from very high in Iran (26.1/10(5)) to low in Israel (12.5/10(5)) and very low in Egypt (3.4/10(5)). Epidemiological studies showed that the prevalence of H. pylori is almost similar in those countries with a high level of infection in childhood. Importantly, the frequency of vacA s1 and m1 regions and cagA+ genotypes were higher in non Semitic populations who inhabit the North than Semitic populations, the inhabitants of Southern parts of the Middle East. H. pylori infection prevalence, distribution pattern of virulence factors, diet and smoking could not have explained the difference in cancer rate. This reflects the multifactorial aetiology of gastric cancer and suggests that H. pylori infection does not always directly correlate with the risk for gastrointestinal disease, such as gastric cancer. Further detailed investigations and international comparative studies of each risk factor need to be performed to investigate whether this represents a true enigma.
闪米特人（阿拉伯人和犹太人）、印欧人（波斯人和库尔德人）和突厥人（土耳其人和土库曼人）。其地理位置受到亚洲、欧洲和非洲的持续影响，使其成为研究幽门螺杆菌（H. pylori）感染和基因分型的理想场所。该地区的胃癌发病率差异很大，从伊朗的高发病率（26.1/10(5))到以色列的低发病率（12.5/10(5))和埃及的极低发病率（3.4/10(5))。流行病学研究表明，在儿童时期感染水平较高的国家，H. pylori 的流行率几乎相似。重要的是，vacA s1 和 m1 区以及 cagA+基因型在北部分居的非闪米特人群中的频率高于居住在中东南部地区的闪米特人群。H. pylori 感染流行率、毒力因子分布模式、饮食和吸烟等因素并不能解释癌症发病率的差异。这反映了胃癌的多因素病因，并表明 H. pylori 感染并不总是与胃肠道疾病（如胃癌）的风险直接相关。需要进一步进行详细的调查和国际比较研究，以研究这是否代表一个真正的谜。
