  The origin of ferromagnetic insulating state of La$_{7/8}$Sr$_{1/8}$MnO$_3$
is investigated. Based on the tight-binding model, it is shown that this state
can be attributed to the Peierls instability arisen from the interplay of spin
and orbital ordering. The importance of the hole-orbiton-phonon intercoupling
in doped manganites is revealed. This picture explains well the recent
experimental finding of the reentrance of ferromagnetic metal state at low
temperature [Phys. Rev. Lett. 96, 097201 (2006)].
