The Oral Bacterium Streptococcus anginosus Also Promotes Stomach Cancer Microbes as Cancer Triggers: It is well known that Helicobacter pylori can cause stomach cancer. But there is another culprit: The bacterium Streptococcus anginosus also promotes the growth of cancerous tumors in the stomach, as a new study has confirmed. According to the study, this microbe is not only found in increased numbers in stomach cancer ulcers, but it also releases methionine, a molecule that f