Stability Transition and Community Structure Shift of Microbial Communities under Antibiotic Stress

Antibiotics profoundly impact microbial growth and host health, yet current understanding is largely based on single-species or simplified communities. How antibiotics reorganize complex community dynamics and structure remains poorly characterized within a coherent framework. Combining experiments with synthetic microbial communities and theoretical modeling, we found that antibiotic exposure leads to community stability transitions in both directions, with increasing antibiotic concentration either driving stable communities transition  to fluctuating or stabilizing previously fluctuating ones. While single species growth is inhibited by antibiotics, increasing antibiotic concentration initially benefits some species through competitor inhibition, while ultimately driving them extinct at higher doses, revealing an emergent behavior of complex microbial communities. Our experiments further show that different timescale of antibiotic exposure can alter the trajectory and final states of the community, thereby exerting a long-term effect on community structure and function. These findings provide a predictive framework for understanding the critical role of species interactions and community dynamics in shaping community responses to antibiotic perturbations.