Are the floor joists on the upper floor positioned perpendicular to the beam in the picture? If so, the beam is likely intended to support the rafters' struts, one or more of which have unfortunately already been cut. To be able to answer your question, one needs to understand the roof structure plus the upper floor's framework. Span lengths, c/c spacing, and dimensions of rafters and floor joists. It's also necessary to know the position of the floor joists in relation to the beam.