Colic -- excessive crying that is unrelated to a medical problem -- is the cause of as many as one in five visits to pediatricians, the researchers said. It is also a source of anxiety and stress for parents.
"In Europe, probiotics are widely used to treat colic," said the study's lead author, Dr. Flavia Indrio, of the department of pediatrics at Aldo Moro University of Bari.
Probiotics are friendly, live bacteria that help maintain a natural balance of organisms in the intestines, Indrio said. To see if probiotics could prevent colic and other gastrointestinal distress, the researchers gave more than 500 newborns either probiotic drops or a placebo.
The results, which were published online Jan. 13 in the journal JAMA Pediatrics, showed that, over three months, the babies who got the probiotics had significantly shorter crying spells and less stomach upset than the babies given the placebo.
"Parents need to be informed that probiotics possibly cure and prevent colic," Indrio said. "This is something I use routinely in my practice to treat colic."
However, although the treatment caused no apparent harm or side effects, Indrio said these findings need to be replicated before this becomes standard care in the United States. The study showed an association between probiotic use and decreased colic, but it did not prove a cause-and-effect relationship.
Colic, acid reflux and constipation are the most common gastrointestinal problems infants suffer. They often result in hospitalizations, feeding changes, drugs and loss of working days for parents, the researchers said.
Normally, the intestines have about 400 types of probiotic bacteria that serve to reduce harmful bacteria and keep the digestive system healthy. One of the most common probiotic bacteria is Lactobacillus, which is found in yogurt and was the bacteria given to infants in this study.
The report was funded by BioGaia AB, Sweden, which makes the probiotic drops used in the study.
Another expert agreed that more research is needed before doctors can embrace the results.
"There is going to be a day -- and it may be soon -- when your pediatrician will give five probiotics a day to prevent your baby from getting colic," said Dr. Bruno Chumpitazi, a pediatric gastroenterologist at Baylor College of Medicine in Houston.
"But even though [this study is] encouraging, there is still a lot of work to be done," said Chumpitazi, the co-author of an accompanying journal editorial. "We don't know how the probiotic works, and we don't know the long-term effects of doing this."
Chumpitazi said colic and associated gastrointestinal problems usually clear up by themselves. However, there might be some long-term effects from colic, he said.
"Kids who have had colic seem to be at risk for abdominal pain with gas-like symptoms later in life," Chumpitazi said. So there might be a benefit to preventing colic, he said.
During the 90-day study, parents recorded the number of times their babies vomited or had a bowel movement or an episode of inconsolable crying (as well as its duration). Parents also reported how many times they saw their pediatrician.
Babies taking the probiotic had an average crying time of 38 minutes, compared with 71 minutes among the infants receiving the placebo, the researchers found.
In addition, kids on probiotics vomited about three times a day on average, while kids on placebo vomited almost five times a day. Those taking the probiotic had an average of about four bowel movements a day, compared with three and a half among those taking the placebo, the researchers found.
Moreover, probiotic use was associated with an average $119 savings for each baby, the researchers said.
Dr. William Muinos, co-director of the division of gastroenterology at Miami Children's Hospital in Florida, is cautious about using probiotics to prevent colic.
"We don't normally treat babies with probiotics," Muinos said. Some babies might be at risk for having the bacteria get into the bloodstream and causing serious illness, he said.
If parents want to give their baby a probiotic, it should be done under the supervision of their pediatrician, Muinos said. "[It should] not be used as a preventive tool, but as a treatment for colic, reflux or constipation," he said.
For more information on colic, visit the American Academy of Pediatrics.