The fiber in pistachios also can help with digestion. Research shows that the fiber in pistachios works as a probiotic and feeds the good bacteria in our digestive tract to improve the health of our digestive system. A single serving of pistachios contains as much as 3 grams of dietary fiber. Developing adult onset diabetes, or Type 2 diabetes, is a common fear for boomers. The American Diabetes Association praises the health benefits of nuts, including pistachios.