Miguel Angel Munoz — Universidad de Granada # A complex-system approach to microbiomes and dysbiosis # Microbiomes are intricate, dynamic communities of microorganisms that influence nearly every aspect of life. In this talk, I will outline key challenges in understanding their collective behavior and summarize recent results suggesting universal regularities in species-abundance patterns. I will discuss how interactions and non-trivial correlations shape community-level outcomes, and how microbial interaction networks often exhibit balanced structures that appear to be disrupted in dysbiotic states associated with disease. Many fundamental questions remain open, making microbial network complexity a rich and rapidly developing field for statistical physics and complex-systems research.