Ingmar Claes

Drying techniques of probiotic bacteria as an important step towards the development of novel pharmabiotics.

The increasing knowledge about the human microbiome leads to the awareness of how important probiotics can be for our health. Although further substantiation is required, it appears that several pathologies could be treated or prevented by the administration of pharmaceutical formulations containing such live health-beneficial bacteria. These pharmabiotics need to provide their effects until the end of shelf life, which can be optimally achieved by drying them before further formulation. However, drying processes, including spray-, freeze-, vacuum- and fluidized bed drying, induce stress on probiotics, thus decreasing their viability. Several protection strategies can be envisaged to enhance their viability, including addition of protective agents, controlling the process parameters and prestressing the probiotics prior to drying. Moreover, probiotic viability needs to be maintained during long-term storage. Overall, lower storage temperature and low moisture content result in good survival rates. Attention should also be given to the rehydration conditions of the dried probiotics, as this can exert an important effect on their revival. By describing not only the characteristics, but also the viability results obtained by the most relevant drying techniques in the probiotic industry, we hope to facilitate the deliberate choice of drying process and protection strategy for specific probiotic and pharmabiotic applications.

Novel opportunities for the exploitation of host-microbiome interactions in the intestine.

New sequencing technologies have dramatically increased our knowledge on the composition of the human intestinal microbiota in health and disease. In parallel, various omics as well as focused molecular studies have revealed novel insights in host-microbiome interactions at the cellular and molecular level. Although these studies are mainly descriptive, advanced microbiota-targeting intervention strategies are being explored, ranging from the selection of novel probiotic strains and synthetic stool substitutes, toward the better monitoring of prebiotic and dietary interventions. It can be envisaged that the efficacy of microbiota interventions will depend on the status of the microbiota of an individual at baseline, but also on genetic and physiological host parameters that determine the capacity to interact with microbes via specific receptors.