This clinical study investigated the effects of subgingival administration of Lactobacillus reuteri in patients with diabetes. The research focused on patients suffering from both periodontitis (gum disease) and diabetes mellitus. The bacterium Lactobacillus reuteri was administered as an oral solution dietary supplement from BioGaia. This supplement was used as an adjunct to standard non-surgical periodontal therapy. Within the study, the effects of this solution were compared against a control group receiving a saline solution. The main sponsor and conductor of this research was the University of Medicine and Pharmacy at Ho Chi Minh City. The study has been completed, focusing on improving oral health outcomes in diabetic patients.