The guidelines for nutritional management are based on the best available evidence as well as survey results and expert opinion. In nearly all areas of these management and monitoring guidelines, collection of more clinical data, well-designed clinical trials, and use of patient registries have the potential to increase the validity of the recommendations. Certain basic information about the pathophysiology of PROP is still not well understood and more research will help us gain an understanding of the nutrition management of PROP, especially:

• The balance between intact protein and medical food protein that will promote normal plasma amino acids and improve outcomes (L.295)
• The effect of propionic acid and other metabolites on mitochondrial function and the possible benefit of supplements that enhance mitochondrial function (L.289, L.290)
• The effect of PROP on the gut microbiome and vice versa (L.291)

In addition, future research will be able to evaluate current and novel therapies that are under investigation, such as: 

• Enzyme replacement therapy (L.292)
• Further evidence on the benefit of carglumic acid in treating hyperammonemia associated with PROP (L.293) 
• Long term outcomes of liver transplantation in PROP (L.294)