, Greensboro, NC) were assembled according to the manufacturer’s instructions and maintained at 37°C in ambient atmosphere. As previously described, one mL of L. reuteri (OD600 = 0.1 or 7 × 107 cells) was injected

into the flow cell [44]. L. reuteri were allowed to adhere to the glass surface for an hour before being selleck chemical continuously supplied with 25% MRS (v/v) at 2 mL per minute. Cell counts verified that the selected flow rate removed planktonic cells and retained adherent bacteria on the surface of the flow cell. After 48 hours, the flow cells were collected and washed once with sodium phosphate buffer (50 mM) for 10 minutes at 37°C, 70 rpm. L. reuteri biofilms were stained with acridine orange for imaging by confocal microscopy. Preparation of cell-free supernatants from L. reuteri planktonic cultures for immunomodulation studies For planktonic cells, 10 mL of LDMIIIG was inoculated with L. reuteri cultures (incubated 16–18 hrs) and adjusted to OD600 = 0.1.

Bacteria were incubated for 24 hours at 35°C in anaerobic conditions. Cells were pelleted (4000 × g, RT, 10 minutes) and discarded. Supernatants were filter-sterilized (0.22 μm pore size). Aliquots were vacuum-dried and resuspended to the original volume using RPMI. Preparation of cell-free supernatants from L. reuteri biofilms for immunomodulation studies For biofilms grown in 24-well plates, L. reuteri cultures (16–18 hrs of incubation) were diluted 1:100 in 1 mL of MRS broth. Plates were incubated anaerobically for 24 hours at 35°C. Supernatants and planktonic cells were removed by aspiration, and biofilms were washed with 50 mM sodium phosphate buffer (37°C, 100 rpm, 10 STI571 minutes). One mL of LDMIIIG was added to each well, and the plates were incubated for 2 hours at 35°C in anaerobic conditions. The supernatants were filter-sterilized (0.22 μm pore size), vacuum-dried and resuspended in RPMI to the starting volume. L. reuteri biofilms were cultured in flow cells supplied

with MRS media for the first 23 hours followed by immersion in LDMIIIG at a flow rate of 2 mL per min in ambient atmosphere at 37°C. Biofilm supernatants were collected by sampling effluents, downstream from the chambers containing the biofilms, at the flow cell’s luer lock connection after 24 hours of culture. The supernatants were Niclosamide filter-sterilized (0.22 μm pore size), vacuum dried, resuspended to 1/20 the starting volume in RPMI, and tested for TNF inhibition. TNF inhibition experiments As previously described [45], cell-free supernatants of L. reuteri planktonic cell or biofilm cultures (5% v/v) and E. coli O127:B8 LPS (100 ng/mL) were added to human THP-1 cells (approximately 5 × 104 cells). Plates were incubated at 37°C and 5% CO2 for 3.5 hours. THP-1 cells were pelleted (1500 × g, 5 minutes, 4°C), and TNF quantities in ROCK inhibitor monocytoid cell supernatants were determined by quantitative ELISAs (R&D Systems, Minneapolis, MN). Preparation of cell-free supernatants from L.