

A gastric culture is a test done on children that looks at the stomach (gastric) contents to identify the microorganism that causes tuberculosis (mycobacterium tuberculosis).
A gastric culture is done in children because when they cough up tuberculosis bacteria from the lung, rather than spitting it out, they swallow the mucus. Children cannot cough up mucus and then spit it out until about age 8. That is also why young children cannot spread tuberculosis.