Probiotic supplements, yogurt, or other fermented foods can lower blood pressure, according to research published in the journal Hypertension. Australian researchers examined nine earlier studies that followed a total of 543 people, and found that consuming probiotics for at least eight weeks lowered systolic blood pressure (the top number) by an average 3.56 millimeters of mercury (mm Hg), and diastolic blood pressure (the lower number) by an average 2.38 mm Hg. People with slightly elevated blood pressure experienced the biggest drop. The most effective supplements contained multiple strains of probiotics. An effective daily dose was at least 100 billion colony forming units (CFUs).