Lactobacilli and bifidobacteria are commensal and/or indigenous bacteria common to the gut of mammals.
These bacteria are always present in our external environment.
The safety of lactobacilli in infants, including newborn babies, and immuno-compromised people has been verified in numerous clinical studies, in which doses of up to 1011 cfu (colony forming units) were given.
The normal dosage range is 108-109 daily. Formal documentation of safety is limited to those bacteria used in studies.
Rare cases of septicaemia have been reported and ongoing surveillance remains critical.
Prof. Bengt Björkstén MD, PhD
Prof.em. of Paediatrics and Allergy prevention
Karolinska Institute, Stockholm, Sweden