Yacon is a root vegetable from the Andes. It contains high amounts of fructooligosaccharides (FOS), a prebiotic fiber that feeds beneficial gut bacteria. The root is often made into a low-calorie syrup and used as a sweetener. Some evidence points to possible help with blood sugar regulation and satiety, but human studies are limited.
A typical daily dose is 1 to 2 teaspoons of syrup mixed into drinks or food. Taking too much can cause digestive upset, including gas, bloating, and diarrhea. There is not enough safety data for use during pregnancy or breastfeeding.