Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 11 4 2019 09 17 294 299 Kurniawan Kadafi Department of Pediatrics, Division of Pediatric Emergency and Intensive Care, Saiful Anwar General Hospital, University of Brawijaya, Malang, Indonesia Satrio Wibowo Department of Pediatrics, Division of Pediatric Gastroenterology and Hepatology, Saiful Anwar General Hospital, University of Brawijaya, Malang, Indonesia 2019 07 14 2019 09 17 Background and Objectives: The aim of this study was to compare the systemic humoral immune responses, including IgE, IgA, IgG and IgM levels in Balb/c mice administered a probiotic, LPS derived from Escherichia coli (E. coli), and probiotic-LPS derived from E. coli. Materials and Methods: Thirty-two male Balb/c mice, 10-12 weeks of age with body weight ranging from 30-40 g were randomly divided into four experimental groups (n=8). The treatment regimens were as follows: Group 1, mice did not receive LPS or probiotic (control group); Group 2, mice received only LPS on the first day; Group 3, mice received probiotic for 7 days; Group 4, mice received LPS on the first day, and then continued, with probiotic for 7 days. The mice were observed for 8 days, and then, euthanized the next day (day 9). The serum was collected, and the levels of IgE, IgA, IgG and IgM were measured using ELISA. Results: The humoral immune response was higher in the presence of a probiotic compared to that in the control; IgE (9.02 ± 0.58 units/ml, p=0.000), IgA (3.26 ± 0.99 units/ml, p=0.316), IgG (7.29 ± 0.24 units/ml, p=0.000), and IgM (4.01 ± 2.98 units/ml, p=0.505). When administered with LPS E. coli along with probiotic, the humoral immune response was the highest; IgE (10.68 ± 1.63 units/ml, p=0.000), IgA (8.34 ± 1.47 units/ml, p=0.000), IgG (9.96 ± 0.98 units/ml, p=0.000), and IgM (4.31 ± 1.05 units/ml, p=0.319) compared to the control group. Conclusion: Probiotic-LPS derived from E. coli treatment induced a higher humoral immune response (highest IgE, IgA, IgG and IgM levels) compared to treatment with probiotic only. https://ijm.tums.ac.ir/index.php/ijm/article/view/2251 https://ijm.tums.ac.ir/index.php/ijm/article/download/2251/1180