Probiotics could be women’s post-pregnancy secret weapon for reducing belly fat, according to the findings of a new study on weight gain by the University of Turku in Finland.

During the study, researchers divided 256 pregnant women into three groups. Some women received dietary counseling along with salad dressing, spreads, fiber-enriched pasta, cereal and other foods. Women in another group were also given—in addition to the counseling and special foods—commonly used probiotics, “good” bacteria that support a healthy bacterial balance in the gut. Participants in the third group received only placebos and no dietary counseling.

Additionally, researchers weighed all of the women at the study’s start and again one year after childbirth. They also measured each woman’s waist circumference and skin fold thickness.

“The women who got the probiotics fared best,” said Kirsi Laitinen, a nutritionist and senior lecturer at Turku. “One year after childbirth, they had the lowest levels of central obesity as well as the lowest body fat percentage.”

Read “Digest This!” to learn more about probiotics.