Relation between lower respiratory tract microbiota and type of immune response against tuberculosis

In this study, the interaction between the microbiota of the lower respiratory tract and the type of immune response against Mycobacterium tuberculosis were studied. Bronchoalveolar lavage (BAL) samples of 10 tuberculosis (TB) patients and 5 cases suspected of lung cancer as control were obtained. Clinical symptoms were recorded for the TB patients. Serial dilutions of samples were prepared and cultured on a selective medium in order to count Streptococcus spp., Neisseria spp., Haemophilus spp. and Veillonella in the lung. To determine the type of immune response of Th1/Th2, Real Time-PCR method was used. The prevalence of Streptococcus spp. in the lungs of patients with TB increased when compared with the control group and the Th1-response in this group may be influenced by Neisseria and Haemophilus. However, reducing the number of Streptococcus and Neisseria can be involved in the development of Th1-response in the control group. Prevalence of Neisseria and Veillonella of the lung microbiota in this group may be associated with fever. The chest x-ray influenced both Th1 and Th2-responses in the lung, but only Th1-response was involved in reducing the weight of patients. The relationship between each of the clinical symptoms with immune response and with each genus of microbiota were reviewed separately, and these data are the new information on TB disease and can be the beginning of the study on the impact of genus, different species and strains of microbiota on the clinical signs of disease.