Matter is distributed uniformly in any direction as we look out in any direction. Surveys of the radial distribution of matter have been conducted on a very large scale, using the relationship between redshift, recessional velocity and distance and on the largest scales, only very small departures from uniformity have been found.
It is part of Big Bang theory that the Big Bang occurred throughout the space that was created along with it, which implies homogeneity in the distribution of matter observed above.