Background: As a multi-functional cytokine, interleukin-6 (IL-6) is advanced in endometriosis. Probiotics are known to be able to modulate/regulate immune responses through downregulation of the pro-inflammatory cytokine IL-6. Lactobacillus plantarum IS-10506 (LIS-10506) is a novel probiotics strain derived from curd (a milk product which look like a yogurt) from traditionally made from buffalo milk or usually called by dadih from West Sumatra, Indonesia. This investigation intended to comprehend the impact of LIS-10506 administration on IL-6 expression in the endometrial tissue, serum IL-6 levels and endometriosis implant areas in mice model for endometriosis. Methods: This study conducted at the Animal Laboratory, Professor Nidom Foundation, Surabaya, Indonesia from January to June 2021. This experimental study was conducted on 32 adult female mice 12 weeks old divided into 4 groups in a completely randomized design with a posttest only control group design. LIS-10506 microencapsulation of curd was administered orally at a dose of 109 CFU/mice/day for 7 and 21 days. Serum IL-6 levels were assessed using IL-6 ELISA Kit for mice, IL-6 expression was assessed semi quantitatively according to the Remmele method and implant areas were measured by the area of hyperemia in mice’s peritoneal wall. Result: This investigation revealed that the peritoneal IL-6 expression and implant area experienced a decrease. In summary, the administration of LIS-10506 could downregulate pro-inflammatory cytokine IL-6. This present study has demonstrated the effect of LIS-10506 on one of the pathophysiological pathways in endometriosis.