NOW Women's Probiotic has been specially formulated using three clinically tested probiotic strains to support women's health through every stage of life. This product features L. rhamnosus HN001 and L. acidophilus La-14 which have been shown to colonize the vaginal tract and help to maintain healthy vaginal pH when taken orally. Both the B. lactis HN019 and HN001 strains may help to support healthy immune system function in pregnant and nursing women. HN019 also supports GI regularity and reduces occasional gas and bloating. These specialized strains also support healthy, balanced immune system function in women of all ages.