S1	MH "Dietary Proteins+" OR ( ( TI ( protein OR hydrolysate OR hydrolys* OR hydrolyz* ) ) NOT formula* ) OR ( ( AB ( protein OR hydrolysate OR hydrolys* OR hydrolyz* ) ) NOT formula* )
S2	MH "Milk, Human+" OR TI ( ((human or breast or expressed) N2 milk*) ) OR AB ( ((human or breast or expressed) N2 milk*) ) OR TI ( ((mother* or maternal or donor*) N2 milk*) ) OR AB ( ((mother* or maternal or donor*) N2 milk*) ) OR TI "breastmilk" OR AB "breastmilk"
S3	( (infan* OR newborn OR neonat* OR premature OR low birth weight OR VLBW OR LBW) ) AND ( (randomized controlled trial OR controlled clinical trial OR randomized OR placebo OR clinical trials as topic OR randomly OR trial OR PT clinical trial) )
S4	S1 AND S2 AND S3