The appendix has long been thought to be a vestigial organ – a leftover, useless thing from earlier times. But a recent study indicates it may serve as a natural reserve of beneficial bacteria for the body, helping the body recover from – and prevent a recurrence of – intestinal disorders.

During infections of the gut, such as cholera, good bacteria in the region are depleted. It is believed that the appendix’s abundant bacteria help restore their ranks following such an infection.

For the study, researchers analyzed the records of 254 patients admitted to Winthrop University-Hospital in New York between 2005 and 2007. All subjects were over the age of 18, and all were admitted for an infection by a deadly bacterium, Clostridium difficile, that causes gastrointestinal distress. C. difficile infections are common among patients on prolonged courses of antibiotics.

James Grendell, chief of the Gastroenterology, Hepatology and Nutrition division, and his colleagues theorized that those patients without an appendix would be more likely to experience a recurrence of C. difficile. Their findings confirmed this theory: Some 48 percent of patients without an appendix experienced a recurrence of the infection – compared to just 11 percent of patients with an appendix. Thus, those without an appendix were four times more likely to have a recurrence of the gut infection.

In addition, researchers found that patients over 60 were more likely to have a recurrence of C. difficile, whether they still had their appendix or not.

The findings have been published in the journal Clinical Gastroenterology and Hepatology.