the collection of all microorganisms that are present on the human body (especially gastrointestinal tract, skin, upper respiratory and reproductive tract)


the total microbial DNA of the organisms present on the human body (especially gastrointestinal tract, skin, upper respiratory and reproductive tract)


the genetic material of an organism


live micro-organisms that, when administered in adequate amounts, confer a health benefit to the host (World Health Organization definition from 2001)


the conversion by bacteria, molds or yeast of certain molecules in a product resulting in a change in pH, taste, smell or appearance. Examples are yogurt, beer, sauerkraut,…

Spray drying

an industrial method to produce powder from a liquid solution. In this technique, a solution is passed through an atomizer, and then sprayed into a drying chamber. Due to the heat, the mist dries and a powder with a small particle size is obtained.




the part of the upper respiratory tract that is above and behind the soft palate, at the same height as and immediately following the nasal cavity

Chronic rhinosinusitis (CRS)

chronic inflammation of the nose and sinusses that takes more than 12 weeks

Otitis media

a spectrum of disease conditions characterised by accumulation of fluid in the middle ear cavity and inflammation of the middle ear cleft


a microorganism that can cause a disease