Bac3Gel startup is based on a revolutionising technology to produce artificial mucus of different body districts in healthy and pathological conditions, including intestinal, lung, vaginal and stomach. Bac3Gel recreates key features of mucus, including gradients of oxygen, structure, viscoelastic properties and nutrients, known to control bacterial behaviour and crosstalk in the human body. Bac3Gel can be exploited to recreate gut, lung, vaginal and stomach microbiota in vitro to evaluate the effect of therapeutic molecules (antibiotics, nutraceuticals, probiotics, prebiotics, vitamins, and other food supplements) over complex bacteria communities. It is compatible with high-throughput screening and/or dynamic systems. Bac3Gel can also be exploited to determine the permeability of therapeutic molecules through human mucus. Bac3Gel is fully tuneable (culture media, DNA, proteins, lipids, among others), and its properties and structure can be modified accordingly to the organ and physiological or pathological scenario.