A common stomach bug, Helicobacter pylori (H. pylori), could be responsible for millions of preventable cancer cases in the coming years, top researchers have warned.Scientists from the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), estimate that H. pylori infection causes 76% of all stomach cancer cases globally. Despite its serious implications, the infection is often silent, producing no noticeable symptoms beyond common digestive complaints.No Obvious Signs Until It Is Too LateThe bacteria, which lives in the lining of the stomach, is usually acquired through contaminated food, water, or close contact with infected individuals. It causes tissue damage over time that can eventually lead to stomach cancer.What makes it dangerous is that most people don't realize they're infected. “The vast majority—between 80 to 90 per cent—of infected individuals show no symptoms,” the researchers noted. In some cases, H. pylori may cause painful stomach ulcers, which is when it’s typically detected.Symptoms of stomach cancer are often subtle in the beginning: persistent indigestionbloatingheartburndifficulty swallowingfeeling full quicklyunexplained weight lossfatigueThese can easily be mistaken for common gastrointestinal issues, which delays diagnosis and treatment.Screening could save livesThe IARC team is now calling for more widespread screening for H. pylori, using simple blood, breath or stool tests. Writing in the journal Nature Medicine, they warn that if current trends continue unchecked, nearly 12 million people born between 2008 and 2017 will go on to develop stomach cancer due to the bacteria.“We found that about three-quarters of all stomach cancer cases globally could be prevented with proper screening and treatment,” said Dr Jin Young Park, lead author of the study and head of IARC’s gastric cancer prevention programme. “It is essential that health authorities make gastric cancer prevention a priority and accelerate efforts to control it.”Asia Is Most Affected, But The Risk Is GlobalWhile the highest number of predicted cases is expected in Asia, around 2 million are projected to develop in the Americas and 1.2 million in Europe.In the UK, data from Cancer Research UK (CRUK) shows that H. pylori is responsible for roughly 41 per cent of the 6,500 stomach cancer cases diagnosed annually—about 2,700 cases a year.Historically, about 40% of the British population has tested positive for H. pylori, although rates are now believed to be declining. However, the risk persists, especially among older generations or those born in areas where the bacteria is still widespread.Prevention Lies In Lifestyle ChangesDespite the global warning, CRUK has urged Britons not to panic. Dr Rachel Orritt, the charity’s health information manager, stressed that lifestyle factors such as smoking, poor diet, alcohol consumption and obesity remain more significant contributors to cancer risk in the UK, as reported by DailyMail.“Although this is an important issue worldwide, in the UK other preventable factors cause more cancer cases,” she said. “Ways to reduce your cancer risk include stopping smoking, keeping a healthy weight, cutting down on alcohol and eating a healthy, balanced diet.”CRUK also highlighted that over half of all stomach cancers in the UK are preventable, and that incidence rates have fallen by more than 25% in the past decade—a trend that is expected to continue.Early Signs You Should Not MissDoctors advise that persistent symptoms like indigestion, nausea, weight loss, or discomfort in the upper stomach lasting more than three weeks should prompt a visit to a GP. Around 18 people in the UK and 83 in the US are diagnosed with stomach cancer every day. The disease remains difficult to treat once advanced, with only 17 per cent of UK patients surviving beyond 10 years post-diagnosis.With screening and treatment, H. pylori infection can be managed—and lives saved. The challenge lies in catching it before it silently progresses to something far more dangerous.