Although causality remains to beconfirmed, current evidence supportsthe view that the gut microbiota play rolein human health and disease. If so, it islogical to assume that manipulation ofthe gut microbiota, such as through theadministration of probiotics could potentiallybe a preventive and/or therapeutic measurein the evolution of disease states. Here,some examples of current research relatedto probiotics are described.Certain probiotics prevent NEC.Controversy exists whether current evidenceis sufficient to change practice and startthe routine use of probiotics in preterminfants to prevent NEC. Lactobacillus reuteriDSM 17938 is likely to reduce crying timesin breast-fed infants with infantile colic.More studies, especially in formula-fedinfants, are needed. Recently, for the firsttime, it was documented that L reuteri waseffective for preventing infantile colic inboth breast-fed and formula-fed infants.A number of randomized controlled trialsfound that probiotics (e.g. Lactobacillus GGand L reuteri DSM 17938) reduced the riskof gastrointestinal and/or respiratory tractinfections. The use of probiotics with provenclinical efficacy [e.g., Lactobacillus GG, S.boulardii, L reuteri DSM 17938] is in linewith current European recommendations forthe management of acute gastroenteritis.There are studies that show a protectiveeffect, no effect, or even a predisposingeffect of using probiotics for preventing theallergic condition. In 2015, the World AllergyOrganization (WAO) published evidencebasedrecommendations about the useof probiotics in the prevention of allergy.According to these recommendations (allare conditional and supported by very lowquality evidence), current evidence doesnot indicate that probiotic supplementationreduces the risk of developing allergy inchildren. However, the WAO considersthat there is a likely net benefit fromusing probiotics resulting primarily fromprevention of eczema. The use of probioticswas suggested in pregnant women at highrisk for having an allergic child; in womenwho breastfeed infants at high risk ofdeveloping allergy; and in infants at high riskof developing allergy. For healthy infants,the administration of currently evaluatedprobiotic-supplemented formula to infantsis safe with regards to growth and adverseeffects.