Raul Cabrera - Rubio

bution of host genetic factors (the FUT2 genotype in particular) on differences in the gut microbiota between patients with Crohn disease and healthy individuals. Thus, an intimate relation between host genetics and bioactive components is expected and should be linked to both infant microbiota colonization and immune system development. The process of microbial colonization of the infant’s gut plays a pivotal role in the metabolic and immunologic development of the child. Deviations from the characteristic microbiota of the healthy breastfed infant are associated with an increased risk of allergic and inflammatory conditions as well as obesity. The transfer of microbiota via breast milk from mothers to infants is influenced by maternal allergic and obesity status (10, 11). Therefore, the different species of bifidobacteria and lactic acid bacteria present in the breast milk of allergic and obese mothers are expected to influence infant gut colonization through a constant daily inoculum during breastfeeding. Thus, modulation of maternal gut microbiota during pregnancy and lactation could have a direct effect on infant health, and microbes present in milk should be characterized to evaluate if this microbiota could be a source for future and specific probiotic strains. We hope that our article stimulates further work to determine the role of host factors in modulating the composition of the human microbiota, enabling new applications in the field of personalized nutrition and medicine.