Abstract
The gut microbiome plays a pivotal role in human health, yet its complexity has long eluded detailed study under physiologically relevant conditions. Hydrogel-based models are revolutionizing microbiome research by bridging the gap between traditional in vitro systems and the complexity of in vivo environments. These advanced systems replicate key physical and biochemical features of the gastrointestinal tract, offering unprecedented opportunities to study microbial behavior, adaptation, and interactions within three-dimensional, tunable architectures. Unlike suspension cultures, hydrogels provide porous, mucosa-like environments that enable the cultivation of mucosa-associated microbes, co-culturing with human cells, and mimicking healthy and disease-related states. This review explores the transformative potential of hydrogel matrices in unveiling the spatial organization, nutrient gradients, and community communication that define microbial ecosystems. By integrating the benefits of in vitro and in vivo models, hydrogel-based platforms promise to accelerate discoveries in microbiome science, with far-reaching implications for understanding human health and developing targeted therapeutics. Video Abstract.