Over the last century, antibiotics have been one of the main pillars of modern medicine and have considerably contributed to the increase of our life expectancy. However, their overuse combined to the rapid adaptation power of bacteria has led to the emergence of antibiotic resistance and to health issues associated with their impact on the human gut microbiota. In a recent study, we measured the impact of 144 different antibiotics on 40 human gut microbes in vitro and observed that different antibiotic classes displayed distinct inhibition spectra. We also noticed that textbook bacteriostatic antibiotics were killing gut microbes and identified strategies, using drug combination, to reduce the impact of antibiotics on gut bacterial communities. We next explored the impact of non-antibiotic drugs on human gut microbes and on antibiotic resistance. By performing experimental evolution in the presence of non-antibiotic drugs and testing the resistant bacteria for antibiotic sensitivity, we identify drug pairs involved in cross-resistance or collateral sensitivity. This observation suggests that exposing gut microbes to non-antibiotic drugs contributes to the selection of antibiotic resistance. Finally, we are currently working on better understanding the diverse effects of antibiotics in different bacteria, on the emergence and spread of resistance elements in the gut bacterial communities and on developing new strategies for better treatment.