Eating pistachio nuts may help the growth of potentially beneficial gut bugs and promote digestive health, says a new study.

Pistachios are also an excellent source of vitamin B6, copper and manganese and a good source of phosphorus and thiamin. Gut bugs help in digestion of food in the stomach.

They may play a role in "modifying microbiota (microbial environment in the gastrointestinal tract) ... for supporting intestinal health," said Volker Mai, assistant professor at the University of Florida`s Institute of Food and Agricultural Sciences.

To examine this link between prebiotics in pistachios and the gut, researchers conducted a study at the Beltsville Human Nutrition Research Center in Maryland. Prebiotics are a functional food that stimulates the growth of healthy bugs, helping produce digestive enzymes.

A group of healthy individuals were randomly assigned to eat an American-style, pre-planned diet that included either 0 ounces, 1.5 ounces or 3 ounces of pistachios or almonds per day, according to a Florida statement.

Each participant`s diet was calorie-controlled to ensure they neither gained nor lost weight during the intervention. Multiple stool samples were collected throughout the study and analyzed for bacterial community composition.

After controlling for age, dietary factors and other relevant variables, the researchers observed that after 19 days, people who ate up to three ounces of pistachios (about 147 nuts or 2 servings) per day had increased changes in levels of various gut bacteria.

The difference in gut microbes was stronger in people who ate pistachios rather than almonds. The researchers used "modern high throughput sequencing" to quantify specific gut bacterial DNA signatures before and after nut consumption.

According to the researchers, this is the first study using this method to observe that pistachios and almonds may have the ability to help change the amounts of bacteria thriving in the gut.