  We investigate the properties of dispersion spectra of one-dimensional
periodic Bose systems with repulsive interparticle interactions. These systems
with sufficient large interactions can support metastable supercurrent states,
which correspond to the local minima of the dispersion spectra at non-zero
momenta. The existence of local minima in the spectra and the energy barriers,
which separate the minima, can be explained in terms of Bose exchange symmetry.
We extend our study to the case of higher dimensional Bose systems. We suggest
that superfluidity could be understood as a Bose exchange effect.
