Behaviour in real time of cellular lines in the presence of bioactive compounds: interaction of surface components from Bifidobacterium with colonocyte-like HT29 cells

Abstract

The definition of a >healthy> human microbiota is unclear; but, it is known that a dysbiosis, or imbalance, of the microbial population inhabiting our digestive tract could be cause of, or is related to, several disorders. This indicates that the interaction between microorganisms and host is paramount to keep our wellbeing. The use of probiotics for prevention and treatment of intestinal disorders, as well as for restoration of microbiota after drastic treatments, is becoming more popular and the scientific evidence of efficacy is also increasing. However, not all probiotics have the same capability to confer health benefits on the host. Therefore, it is crucial the use of reliable, reproducible and fast methods monitoring the host response in the presence of probiotics. We have recently implemented in our group a technique based on the use of a ¿Real Time Cell Analyser¿ apparatus to test the behaviour of cellular lines (in proliferative or in confluent state) from human (colon) origin in the presence of different Bifidobacterium strains, extracellular polymers (exopolysaccharides) and bacterial surface extracts, among others. Preliminary results showed that, for a given bacterial compound at different doses, the behaviour of the eukaryotic cells was very much time-dependent. One of the compounds tested had cytotoxic effect at high dose on HT29 cells; whereas, at lower doses, we have detected an initial anti-proliferative effect ending with cell death. Besides, this behaviour was retarded when the bacterial compound concentration decreased. This method is a valuable tool that could be extended for the screening of different bioactive compounds obtained from different origins