Abstract: In this talk we will discuss the relation between homological properties of Stanley--Reisner rings of simplicial complexes and topology of polyhedral products. A key result in this direction is the characterization of Golod rings over rationals in terms of their Poincaré series and loop homology of the corresponding moment-angle-complexes. Much more can be said if only flag simplicial complexes are considered. We will see how the methods and objects of toric topology allow us to interpret the results on Poincaré series and Koszul homology of face rings as well as to get new results.