Helicobacter pylori (H. pylori) is recognized as a human gastric pathogen that is a major risk factor for the development of peptic and duodenal ulcers, gastric adenocarcinoma, and lymphoma in humans. Antibiotic treatment is not completely effective due to antibiotic resistance. Probiotics play an important role in regulating the immune system and exert antibacterial effects by producing metabolites. Probiotic strains were administered to infected mice, and immune responses were monitored to investigate their immunomodulatory effects. Pathogen-free male C57BL/6 mice were divided into 6 groups of 5, and treatments were administered. Fourteen days after the last treatment, their spleens were removed, and IFN-γ and IL-4 expression levels were measured by real-time PCR. After treatment of L. acidophilus ATCC4356 and L. rhamnosusPTCC1607, the expression of INF-γ increased, but IL-4 expression was decreased. It can be concluded that the functions of probiotic strains differ. Two probiotics, L. acidophilus ATCC4356 and L. rhamnosus PTCC1607, stimulate interferon-gamma production to increase the phagocytic activity of macrophages and facilitate the differentiation of T cells to Th1.
Bacterial resistance to antibiotics is considered the most important health problem in developed and developing countries. Studies on new pharmaceutical strategies, such as probiotics and their derivatives, have increased. The purpose of this study is to isolate and purify bacteriocin and biosurfactant from Lactobacillus rhamnosus and investigate its antibacterial and anti-biofilm activity. Bacteriocin and biosurfactant produced by Lactobacillus rhamnosus standard strain were isolated and purified. Biosurfactant screening tests, including oil expansion test and drop spreading test, were conducted. Bacteriocin was separated using two different methods, including separation with the help of 2-propanol and separation with the help of ammonium sulfate. The purification of bacteriocin was realized by dialysis, and the effect of biosurfactant and bacteriocin on Staphylococcus aureus and Escherichia coli was realized using the disc diffusion method. The antibacterial properties of these substances were determined by diffusion method from its anti-biofilm disk with the help of the ELISA reader. Statistical Program for Social Sciences (SPSS) software was utilized for data analysis. The diameter of the non-growth halo of E.coli in contact with the disc impregnated with bacteriocin in concentrations of 250, 500, and 1000mg/ml was 21 ± 1, 21.33 ± 2.3 and 34.66 ± 7.02 mm, respectively, and in Staphylococcus aureus was evaluated as 18.33 ± 3.78, 24.33 ± 4.72 and 43.66 ± 4.72 mm, respectively. The order was evaluated as 18.33 ± 2.88, 25 ± 5, 43.33 ± 5.77 mm. The biofilm inhibition percentage was measured for Escherichia coli 0.36, 2.15, and 71.75%, respectively, and for Staphylococcus aureus 1.07%, 5.96%, and 53.3%, respectively, at the mentioned concentrations. The results showed that bacteriocin and biosurfactant isolated from Lactobacillus rhamnosus have high antibacterial and anti-biofilm properties
