Microbial communities represented by commensal bacteria of Staphylococcus epidermidis & Corynebacterium spp (C. amycolatum, C. accolens, C. pseudodiptheriticum and C. propinquum) and potential pathogens Staphylococcus aureus & Haemophilus influenzea respectively. The microbial communities (single bacteria and combinations) were co-cultured with differentiated human respiratory epithelial cells (Calu-3) and this co-culture model was then used to assess differences in host response on exposure to either ?healthy? / ?disease? associated microbiota or their mixture. In addition, Human rhinovirus (HRV) and TNF alpha were added to the above-mentioned co-culture model to study host?s response to viral infection and inflammation stimulation respectively. 

Results: Successful co-culture of bacteria (single and combination) with Calu-3 cells for up to 72 hrs without any cytotoxic effect (LDH assay) and barrier integrity impairment was achieved. Significantly reduced/increased levels of IL-6 and IL-8 were observed by commensals and pathogens respectively.

TNF alpha stimulation of the established co-culture of Cau-3 cells and microbial communities resulted in increased cytokine production of IL-6 by 3-4 folds and IL-8 by 2 folds in addition to impaired barrier integrity of epithelial cells after 24 and 48 hours of treatment. Infection of microbial communities and epithelial cells co-culture with HRV resulted in significantly increased IL-6 by 3-4 folds and IL-8 by 2 folds along with impaired barrier integrity of epithelial cells after 24 and 48 hours of treatment.