There is limited evidence that some of these effects could be maintained in the medium term, as another study that followed chronic periodontitis patients for up to a year after a 3-week course of L. reuteri lozenges after scaling and root planning procedures found a reduction in GCF matrix metalloproteinase-8 (MMP-8) and an increase of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) up to 180 days [44]. This evidence concerns the gene MMP8 and periodontitis.