I will start with a brief review of the observational evidences for the existence of dark matter (DM), of the particle candidates to constitute DM, and of the present status of DM searches. Then, I will describe how the annihilation of huge quantities of DM particles inside stars may influence the stellar properties. I will focus in two strategies to detect these effects: the analysis of the stellar oscillations and the changes in the global appearance of a whole stellar cluster. To conclude I will show how the same approach of using the stellar properties to investigate fundamental physics was successfully applied to test alternative theories of gravity using solar neutrinos and helioseismology.