Authors' Response to Letter

Abstract

To the Editor: We thank Joosten and Lardeau for their interest in the position paper of the ESPGHAN Committee on Nutrition on fermented infant formulae (1). They note that this position paper does not address possible bacteriostatic properties of reconstituted fermented formula powder reported to reduce the proliferation of pathogens in reconstituted formula powder kept at warm temperatures under experimental conditions. The ESPGHAN Committee on Nutrition intended to assess known effects of fermented formulae in infants fed such products, as expressively stated in our commentary (1). Hence, we performed a systematic search and evaluation of literature reporting on the evaluation of effects in infants in clinical trials. This choice was made considering that the determination of properties of dietary products for infants (and of their components) by in vitro and animal experiments may be extremely valuable and often necessary, but that the effects and safety of dietary products for infants must be determined finally by an evaluation of their effects on physiological (eg, growth patterns), biochemical (eg, plasma markers), and functional (eg, immune responses, prevalence of infections or allergy) outcomes in infants fed such products, based on clinical trials meeting current scientific standards (2–5). Therefore, the Committee reviewed the reported effects of fermented infant formulae on health-related outcomes in infants in clinical studies, but did not focus on the results of preclinical studies. It is plausible that fermentation of milk products such as infant formulae, or their acidification by other means, can lead to reduced multiplication of pathogens in formula reconstituted with water and kept at warm temperatures for several hours. To our knowledge, however, it has not been documented that such effects would suffice to ensure the safety of infant feeding with formulae contaminated with pathogenic bacteria that has been prepared and handled under inadequate conditions. Infant formulae and other milk products are excellent media for the proliferation of bacteria, including pathogens, and multiplication of Enterobacter sakazakii in prepared formula feeds can cause devastating disease in infants, particularly in the first 2 months of life (6,7). The ESPGHAN Committee on Nutrition has previously recommended that powdered infant formulae be freshly prepared for each feeding in the home setting (6). Any milk remaining after a feeding should be discarded rather than used in the following feeding. Moreover, the Committee recommended that the manufacturers of infant formulae should make every effort to minimize bacterial contamination of powdered products. In our view, the available database does not support a different recommendation for the preparation and handling of fermented, powdered infant formula. However, because in vitro data suggest that the use of fermented infant formulae over nonfermented formulae may reduce the risk for infectious diarrhea and other relevant outcomes in infants, this hypothesis should be assessed in further randomized controlled clinical trials following current scientific standards (2). If proven to be the case, then such a protective effect may be particularly relevant to infant populations under poor living conditions at high risk for infectious disease and may have considerable relevance for global child health.