Final answer:
The mother should provide a high-protein diet for the infant newly diagnosed with cystic fibrosis to address the impaired salt transfer caused by the condition and promote growth and development.
Step-by-step explanation:
The mother of an infant newly diagnosed with cystic fibrosis should provide a high-protein diet for the infant.
The impaired salt transfer caused by cystic fibrosis can lead to malabsorption, which may affect the infant's ability to absorb nutrients. A high-protein diet can help address this issue and provide the necessary nutrients for growth and development.