Disclosed herein is a skin care composition comprising at least one exopolysaccharide (EPS) originating from a microbial mat, wherein the EPS is in a concentration of about 0.001% w/w to about 1.5 w/w of the composition. Preferably, the EPS is derived from microorganism isolated from microbial mats found in French Polynesia. The composition is useful in reducing and preventing signs of skin aging and environmental damage by altering skin cell metabolism and improving hydration.