(C) upper panel depicts detection of gp340 in parotid saliva alone and after incubation with five different L. gasseri isolates and the L. gasseri type strain; (D) upper panel depicts detection of gp340 and lower panel detection of MUC7 in submandibular/sublingual saliva alone and after incubation with five different L. gasseri isolates and the type strain. Numbers below lanes in panels C and D refer to the following contents: (1) Saliva alone (+ve control), (2) Saliva after L. gasseri CCUG31451T incubation, (3) Saliva after L. gasseri isolate A241 incubation, (4) Saliva after L. gasseri

isolate A274 incubation, (5) Saliva after L. gasseri isolate B1 incubation, (6) Saliva after L. gasseri isolate check details B16 incubation, (7) Saliva after L. gasseri isolate L10 incubation. MUC7 (mw ≈150 kDa) was detected using Western blot analysis with mAb LUM7-2 antibodies in submandibular saliva (Figure 4, lower panels A and B, lane 6, lower panel D lane 1) but not in parotid saliva (data not shown). MUC7 levels were reduced in submandibular saliva after incubation with L. gasseri (Figure 4, Staurosporine nmr lower

panel A, lane 7) and S. mutans (Figure 4, lower panels B, lane 7). MUC7 was detected bound to L. gasseri (Figure 4, lower panel A, lane 8) and S. mutans (Figure 4, lower panel B, lane 8) after incubation with submandibular saliva. SDS treatment

released the MUC7 bound to L. gasseri (Figure 4, lower panel A, lane 9) and to S. mutans (Figure 4, lower panels B, lane 9). Similar results were observed for MUC7 binding to six additional isolates of L. gasseri (Figure 4D, lower panel). L. gasseri binds to human epithelial cells Adherence of FITC-tagged L. gasseri strains was detected by fluorescence microscopy as illustrated for strain A274 (Figure 5). All L gasseri strains were observed only adjacent to epithelial cells. Figure 5 Adhesion Urease of L. gasseri to human epithelial cells. Field of view containing differentiated human gingival epithelial cells (HGEP.05) and fluorescently stained L. gasseri A274 (in green). Bacteria were detected only in association with gingival epithelial cells. Images were captured using a Zeiss imager Z1 upright microscope. Bars in panels equal 20 μm. Discussion In this study lactobacilli were detected more frequently in breastfed than formula-fed 4 month-old infants in saliva and mucosal swab samples as we previously observed in a different population of infants [13]. L. gasseri was the dominant Lactobacillus species detected, which was identified from 16S RNA gene sequences of isolates. Probiotic potential of L. gasseri was found to include growth Bortezomib ic50 inhibition of F. nucleatum, A. naeslundii, A. oris, S. sobrinus and C.