What role does Helicobacter play in gut health?

Helicobacter pylori is a bacterium that colonizes the stomach lining. Its role in gut health is dual: it is the primary cause of chronic gastritis, peptic ulcers, and a risk factor for gastric cancer. Conversely, some epidemiological studies suggest H. pylori may protect against gastroesophageal reflux disease and esophageal adenocarcinoma, but this is not proven causally. In the gut, H. pylori can alter the microbiome by modulating gastric acidity, potentially impairing digestion and nutrient absorption. Importantly, a positive antibody result from a home test indicates past or current exposure, not necessarily active infection. Eradication should only follow clinical diagnosis (breath, stool, or biopsy). The evidence is mixed: strong for harm, moderate for possible protective effects. Without symptoms, routine screening is not recommended. Consumer DNA tests often include H. pylori risk variants, but these have low predictive value and should not replace medical evaluation.