“What foods neutralize stomach acid?”

Alkaline foods. Low acid foods.

The short answer is that all foods neutralize stomach acid, but only to a limited degree. Normal stomach pH is 1 and when you ingest food then you buffer that acid a bit, but eating also stimulates acid production so the buffering is short-lived and the pH goes back to 1 quickly. Even thinking about food causes acid production, in anticipation of eating. The bottom line is that even so-called alkaline foods or drinks, like milk, cannot buffer stomach acid enough to have any clinical effect. In general, one does not need to buffer or control acid unless that acid is causing a problem such as refluxing into the esophagus. Abdominal pain after eating - i.e., this symptom alone - is not necessarily a sign of too much stomach acid. The only things that cause excessive stomach acid are H. pylori infection and very rare tumors.