We integrate the nonpropagating B_μ gauge field for the non-linear BF Lagrangian describing N M2-branes which includes terms with even number of the totally antisymmetric tensor M^IJK in arXiv:0808.2473 and for the two-types of non-linear BF Lagrangians which include terms with odd number of M^IJK as well in arXiv:0809:0985. For the former Lagrangian we derive directly the DBI-type Lagrangian expressed by the SU(N) dynamical A_μ gauge field with a spacetime dependent coupling constant, while for the low-energy expansions of the latter Lagrangians the B_μ integration is iteratively performed. The derived Janus field theory Lagrangians are compared.