ZT：哪些幽門螺杆菌菌株具有更高的致胃癌風險？哪些也許有益？

    http://www.medsky.cn/meida/chaoliu/269.html

幽門螺杆菌的特征是具有高度的種內遺傳多樣性。不同地區人群所感染的幽門螺杆菌菌株不僅在單個基因的序列上有差異，而且表現出基因含量和染色體組織的差異……

感染了含有CagA、s1類型VacA和BabA的幽門螺杆菌菌株的人群，其發生胃癌的風險最高。幽門螺杆菌與胃癌風險相關，且不同類型幽門螺杆菌菌株與胃癌的相關性具有顯著差異。………

 

http://www.mdweekly.com.cn/html/xueshu/huiyizhongxin/2019/0819/22916.html

不同角度看幽門螺杆菌

越來越多的研究顯示，Hp對人體可能存在的保護作用，並且一些研究也反映了根除後會出現的一些問題，包括：Hp實際上是一種與人體共生的有益細菌，被根除後會破壞腸道菌群生態平衡；在發展中國家，攜帶Hp的孩子更不容易患上過敏；兒童時期，攜帶Hp可以降低哮喘的發病風險；攜帶Hp可以降低濕疹的發生率；當Hp從人體的胃中消失後，人們更容易患上胃食管反流病及其並發症（調查顯示，當Hp被根除及胃癌發病率下降同時，食管腺癌的發病率在幾十年後開始上升），比如巴雷特食管和食管腺癌，也更容易體重增加等。此外，2013年的一項研究顯示，根除Hp帶來多種不良後果：50%以上的患者在根除中會出現不良反應；20%作用的概率會根除失敗；根除後腸道菌群的變化可能帶來長期的健康影響；使用抗生素會增加耐藥性細菌產生的風險。………

 

http://sph.54doctors.net/Html/News/Articles/3830.html

　中國人群幽門螺杆菌（Hp）感染率很高達到50%以上，而且一旦感染後如不進行針對治療，很難自然根除。很多人一旦悉知自身感染了Hp就會感覺體內安放了一枚能讓人患胃病甚至是胃癌的“不定時炸彈”。可大多數人感染了Hp卻終身沒有胃病的發生。隨著科學向前深入，發現Hp分為不同類型，Hp菌株基因甚至能起到對我們人類有益菌的作用，而另一些Hp則會讓我們患病的幾率大大增強。

　　研究發現，患有Hp的病人如果不進行分型檢測，而是選擇一旦發現Hp，不論有無症狀都進行根除，那麽我們一定要認識到根除本身會帶來很多意想不到的副作用。近十年來隨著我們大規模殺死Hp，遠端胃癌發病率下降的很快，然而我們驚訝的發現，近端胃癌卻呈現快速的高增長率，我們逐漸認識到Hp其實也許對我們人類起到一定保護作用。

 

https://www.ncbi.nlm.nih.gov/pubmed/30455363

Within human stomachs, RABEP2 and G3BP2 expression in gastric epithelium increased in parallel with the severity of premalignant and malignant lesions and was significantly elevated in intestinal metaplasia and dysplasia, as well as gastric adenocarcinoma, compared with gastritis alone. These results indicate that carcinogenic strains of H. pylori induce dramatic and specific changes within the gastric proteome in vivo and that a subset of altered proteins within pathways with oncogenic potential may facilitate the progression of gastric carcinogenesis in humans.

 

https://www.nature.com/articles/s41598-018-34425-4 

Isolation of less pathogenic H. pylori strains carrying CagA with attenuated pathobiological activity in a small and isolated host population is reminiscent of the result of our previous study regarding v225d CagA, a natural CagA variant of H. pylori isolated from an Amerindian subject living in the Amazon rainforest54. Like Hp_TH2099 CagA, v225d CagA was also incapable of binding with PAR1b, suggesting that attenuated CagA activity, especially loss of PAR1b binding, is a hallmark of H. pylori sustainably cohabiting with a small number of hosts. Although it needs to be determined whether macaques carry and transmit H. pylori among themselves in wild life, many studies have shown that wild macaques have an intimate relationship with humans, especially in Asian countries55,56. It is possible that macaques became infected with H. pylori from human vomit or waste. Conversely, humans might have acquired H. pylorifrom macaques by feeding on them, a human habit that has been historically recorded in many geographic regions of the world. It is tempting to speculate that rapid evolution of distinct H. pylorisubpopulations has been made possible by back and forth natural infection/colonization between humans and non-human primates, which may have facilitated bacterial microevolutions in a way that is milder than the mutation burst triggered by experimental H. pyloriinfection.

 

注

1. 菌亦有別，如這壇子網友，良莠不齊。切勿摸象、孔窺，以點帶麵，或混為一談。

2. 也許又會被人指責：你到底支持還是反對？

      大千世界，本來就是多樣多變。但可以肯定，雜色為主。

      發帖不應預設立場，回帖應論而不辯，或辯而不爭。

3. 易敏者，也許需要來點螺旋菌。