The PRESTO study: Exploring the role of synbiotics in cow's milk allergy

Cow’s milk allergy (CMA) is one of the most common food allergies in early childhood, affecting infants during a critical period of growth and development. While many children eventually outgrow the condition, CMA can place a significant burden on both infants and their families, often requiring specialized diets, careful symptom management and regular medical care. 

“At Danone Research & Innovation (Danone R&I), our multidisciplinary teams are investigating how early life nutrition may help address the challenges of CMA, not only by managing symptoms and meeting an infant’s nutritional needs, but also by shaping the developing gut microbiota,” says Maaike den Os, Clinical Study Researcher in Specialized Paediatrics. “One example of our work is the PRESTO study, which explored the role of synbiotics in children with CMA, including their effects on the gut and longer-term health outcomes”.

CMA occurs when the immune system mistakenly reacts to proteins naturally present in cow’s milk, such as casein and whey. Clinical manifestations can range from skin (e.g: eczema) and gastrointestinal symptoms (e.g: diarrhoea and vomiting) to more severe allergic reactions (e.g: anaphylaxis). 

For infants who cannot be exclusively breastfed, specialized formulas are an important part of dietary management. “Healthcare professionals may recommend an amino acid-based formula for those with severe symptoms or complex nutritional needs,” explains Annelot Breedveld, Scientist in Allergy.

Our experts are becoming increasingly interested in the connection between nutrition, the gut microbiota, and immune development. “Synbiotics have been shown to support beneficial gut bacteria, helping to bring the gut environment closer to that observed in healthy breastfed infants,” notes Annelot.

To better understand their potential role in CMA management, Danone R&I conducted PRESTO, a long-term clinical study that followed 169 formula-fed infants with CMA across 18 sites worldwide. Over a 12-month period, infants received either an amino acid-based formula alone or the same formula enriched with synbiotics. Researchers then monitored the children for several years, with stool, saliva and blood samples collected at regular intervals to assess long-term health outcomes, gut microbiota composition and the development of tolerance to cow’s milk.  

Children in both groups outgrew their allergies, consistent with clinical expectations in CMA. In line with other studies, infants receiving the synbiotic-containing formula showed a gut microbiota composition that more closely resembled that observed in healthy breastfed infants. They also experienced fewer reported infections, reduced antibiotic use and fewer infections requiring hospitalisations. Additionally, long-term follow-up data showed that children in both groups had eating behaviours comparable to those of healthy peers at six years of age.

“These insights contribute to a growing body of research exploring how nutrition can support infants with CMA beyond symptom management alone,” Annelot highlights. “The study adds to the evidence suggesting that promoting a balanced gut microbiota may support immune development and contribute to long-term health.”  

Building on this growing body of knowledge, PRESTO is part of Danone R&I’s broader research program dedicated to advancing our understanding of how specialized nutrition can help support infants with CMA throughout early life.

Learn more about our research on allergies and gut health.

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