Infant colic, acid reflux and constipation are the most common gastrointestinal disorders that lead to a paediatrician referral during the first six months of life.
"They are often responsible for hospitalisation, feeding changes, use of drugs, parental anxiety and loss of parental working days," said Flavia Indrio of Aldo Moro University of Bari, Italy.
Researchers randomised 554 newborns in nine paediatric units in Italy to the probiotic lactobacillus reuteri or placebo for 90 days.
They asked parents to record in diary entries the number of vomiting episodes and evacuations (emptying of the bowels), the duration of inconsolable crying and the number of pediatrician visits.
Change in daily crying time, vomiting, constipation and the cost benefits of probiotic supplement use was measured during the three-month period, said the study published in the journal JAMA Paediatrics.
At three months of age, the average duration of crying time, regurgitations and evacuations per day was less in children who were given probiotic, it added.
"Probiotic improves intestinal permeability, visceral sensitivity and mast cell density. The probiotic use in infants may represent a new strategy for preventing many gastrointestinal conditions," the authors said.