Type 1 diabetes (TlD) is considered to be an autoimmune disease leading to destruction of the insulin producing beta cells in pancreas. Interaction between genetic factors and environmental factors are believed to trigger the autoimmune response finally causing T1D. A number of environmental factors have been suggested to be associated with TlD. Microbiotic colonization of the newborn infant's gut ecosystem by specific bacterial species may be important in the initial regulation of the developing immune system. Development of TlD has been associated with intestinal immune activation and enhanced immunity to food antigens. Probiotics is defined as nonpathogenic cultures of living bacteria with a health-promoting effect. The effect of probiotics is unspecific, likely mediated via the modulation of the innate immune system. The actions of probiotics in the prevention of TID could include reduced occurrence of enteral virus infections, enhanced maturation of the gut immune system, decreased gut permeability, and support for development of oral tolerance and/or induced immune regulation. The aim was to test the safety of probiotics in infants with risk genes for TlD and to study the effect of probiotics on the activation stage of monocytes ex vivo and on their response to in vitro LTA and LPS stimulation. We conclude that probiotics seems to be safe and we demonstrate here to our knowledge the first evidence in humans that probiotics are able to modulate the function of monocytes in vivo and even longstanding effects of the treatment during the early infancy are seen. The findings support the hygiene hypothesis suggesting that early microbial exposure may program the function of the innate immune system for later life. The probiotic induced hyporesponsiveness of the innate immune system to stimuli may protect from over-whelming inflammatory responses that could further contribute to the development of harmful innate and adaptive immune responses seen in allergies and autoimmune diseases. These results explain, at least partly, the beneficial effects of probiotics seen in the prevention and treatment of allergies in children.