In a recent work published in the front cover of Advanced Materials, researchers from 3B’s Research Group, University of Minho, in collaboration with Canary Center for Cancer Early Detection, University of Stanford, developed a new class of natural sugar-based hydrogel optical fibers. These flexible hydrogel structures enable the optical detection of processes such as mechanical deformation and the presence of biotargets such as SARS-CoV-2 viruses. Moreover, these innovative fibers can guide light while simultaneously transporting living entities, as human cells. Exploring the interaction between optical signals and biological events such as cell proliferation, these living optical fibers allow for the digitalization of, for example, the growth of a miniature tumor within the fiber, enabling the test of anti-cancer drugs in a quantitative and extremely rapid fashion. This technology can be easily adaptable and may integrate cells from specific patients to test therapies, representing an important advance for precision and personalized medicine