We studied whether viscosity influence gut microbiota growth by supplementing the medium with bacteriological agar. Depending on the species, the bacteria growth is different; also bacteria changed the medium, even keeping constant GNM conditions (temperature and pH). Along the gastrointestinal tract, there is a constant change in viscosity that is not usually taken into account. We believe that these changes need to be characterized not only for nutrients diffusion but also for gut microbial developing. Viscosity has to be taken into account for improving in vitro studies where for example fibre ingredients are involved. Additionally, from the small intestine till the descending colon water is being absorbed, then viscosity is changing in an increase fashion, as it is influencing in different growth of bacteria species, it is a key factor to approximate to the reality the gut in vitro systems.

The authors of this work were funded by the Spanish MINECO project (AGL2015-64522-C2-R-01). L.L. would like to thank the Spanish “Juan de la Cierva” program for her contract (ref FJCI-2014-19907). C.C would like to thank the Comunidad de Madrid Program (ALIBIRD-CM S2013/ABI-278-CM) for her postdoctoral research contract. A.T. is the beneficiary of a contract in the Garantía Juvenil-CSIC Program.

Trabajo presentado al Wine and Health Meeting, celebrado en Logroño (España) del 16 al 18 de septiembre de 2017.

Peer Reviewed