Objective: This study aims to examine the effect of giving probiotic adjuvant therapy on improving clinical symptoms & IL-6 levels in patients with schizophrenia. Methods: This research was a double-blind, placebo-controlled trial conducted at Dadi Psychiatric Hospital, South Sulawesi Province, Indonesia in November–December 2021. The sample of the research was patients with schizophrenia undergoing hospitalization who received therapeutic doses of risperidone with a total of 21 samples in each treatment and control group. Research subjects were measured with Positive and Negative Syndrome Scale (PANSS) at baseline, 2nd, 4th, and 6th weeks. The treatment group received one capsule/12 hours/oral of probiotics for six weeks and the control group received 1 capsule/12 hours/oral placebo for 6 weeks. In addition, two measurements of IL-6 using enzyme-linked immunosorbent assay were performed in both groups, namely at the beginning of week 0 and the end of the 6th week. Results: We found the decrease in the PANSS value which described the improvement in clinical symptoms of the schizophrenic group after receiving therapeutic doses of antipsychotics and probiotic capsules or the treatment group as well as the schizophrenia group receiving therapeutic doses of antipsychotics and placebo capsules or the control group. Conclusion Improvements in clinical symptoms and decreased levels of IL-6 in the group of patients with schizophrenia who received risperidone with probiotic adjuvant therapy were better than in the group of patients with schizophrenia who received risperidone without probiotics as adjuvant therapy.