AND RELEVANCE Although L reuteri may be effective as treatment for crying in exclusively breastfed infants with colic , there is still insufficient evidence to support probiotic use to manage colic , especially in formula-fed infants , or to prevent infant crying .
IMPORTANCE  Excessive infant crying  is common , distressing , but without proven effective prevention or management options .
Probiotics may be a promising solution .
OBJECTIVE To examine whether probiotics are effective in the prevention/management of crying ( " colic " ) in infants 3 months or younger .
Effectiveness of casein hydrolysate feedings in infants with colic
This study found that two casein hydrolysate formulas varying in composition were equally effective in managing  colicky symptoms associated with protein sensitivity . Both hydrolysate formulas were associated with a significant , comparable reduction in crying duration and intensity from baseline in 15 of 22 infants with complete data . Subsequent challenge data suggest that the population studied were infants experiencing colicky symptoms due to protein sensitivity . A greater proportion of infants showed a positive reaction ( ≥1.5h of crying/d ) to the protein challenges than the placebo challenge , and crying was rated as more intense during whey and milk protein challenges
AND RELEVANCE Although L reuteri may be effective as treatment for crying in exclusively breastfed infants with colic , there is still insufficient evidence to support probiotic use to manage colic , especially in formula-fed infants , or to prevent infant crying .
IMPORTANCE  Excessive infant crying  is common , distressing , but without proven effective prevention or management options .
Probiotics may be a promising solution .
OBJECTIVE To examine whether probiotics are effective in the prevention/management of crying ( " colic " ) in infants 3 months or younger .