2 Immunoglobulins. hand, IL-38 gene expression was increased by both probiotic and prebiotic treatment. Treatment with probiotics and prebiotics could control levels of IL-4, 5, 13, 25, 33, leukotrienes, the gene expression of AKT, NLR3, NF-B, MyD88, MUC5a. The prebiotic treatment could control peribronchial inflammation and PI3K gene expression. Both of the treatments had no significant effect on the GOT, TSLP and IL-8, eotaxin and CCL24 gene expression. Probiotics and prebiotics could induce tolerance in allegro-inflammatory reactions and alter immune responses in allergic conditions. Probiotics could also modulate cellular L-Leucine and humoral immune responses and prevent allergic disorders. Keywords: Allergy, Microbe, Diet, Immunomodulation, Asthma Main findings of the study Probiotics controls AHR, eosinophil infiltration to the perivascular and BALF, levels of immunoglobulins, IL-17, GTP and also mucus secretion, goblet cell hyperplasia, EPO activity. It could reduce gene expression of TLR4 and CCL11, Probiotics and prebiotics control levels of cytokines (IL-4, 5, 13, 25, and 33), leukotrienes, the gene expression of AKT, NLR3, NF-B, MyD88, MUC5a, peribronchial inflammation and increase IL-38 gene expression. Prebiotic controls and PI3K gene expression. Introduction Asthma, pneumonia, and lung injury are common acute respiratory problems in the clinic and allergic asthma is usually a relatively prevalent condition worldwide. Patients with asthma cannot be cured completely, and all available treatments generally aim to control the pathological condition. There is a huge economic burden on patients and governments [1, 2]. Allergic asthma is one of the most important health problems, especially in developed countries. Several pathways are involved in the pathophysiology of allergic asthma. Immune system dysregulation is directly related to health and is involved in the pathogenesis of a variety of immune disorders, including allergic diseases. On the other hand, the imbalance of inflammatory and anti-inflammatory factors and also dysregulation of the lung immune system through the TLR4/NF-kB signaling pathway can lead to pulmonary oxidative stress and injury [3, 4]. The therapeutic applications of probiotics and prebiotics in diseases such as asthma and pneumonia were not studied very well. Probiotics and prebiotics have been shown to possess immunomodulatory effects and be involved in the pathophysiology of various diseases. Short-chain (galacto-oligosaccharides) and long-chain (fructo-oligosaccharides or lcFOS) prebiotics along with probiotics (beneficial microbes) have also been noted to prevent allergic sensitization via regulating immune responses. Beneficial probiotic bacteria can modulate immune cells such as Th1, Th2, Th17, Treg, and also B cells [5, 6]. There are numerous microbial infections can active TLR4 signaling and probiotics as part of commensal gut microbiota, can have effect on the TLRs, especially TLR4 [7, Rabbit Polyclonal to PKA-R2beta 8]. LPS is usually structural material of bacteria and TLR4 activation by bacteria is initiated via LPS/TLR4/NF-kB pathway [9, 10]. On the L-Leucine other hand, LPS can induce acute lung injury and inflammation, which leads to accumulation of inflammatory cells in the lung and airway [11, 12]. OVA can induce allergic asthma model but, OVA-LPS can induce asthma and acute inflammation in airways. Also, it can involve with TLR4 and actives TLR4 signaling. Therefore, in L-Leucine this study, we explored the functional mechanisms of probiotics and prebiotics in regulating of the hosts defense against LPS-OVA-induced lung injury and airway inflammation and the TLR4/NF-kB pathway. Also, immuno-inflammatory responses and pulmonary pathological features.