Can a probiotic ease colic in breast-fed babies?

Q: When our first son was born, we almost lost our minds as we rode out his bouts of colic. Our second son is due this spring and the idea of dealing with colic again already has me panicking. I've been reading that certain probiotics can help. Is this true?

A: We honestly think it's a tossup as to who suffers more when an infant is caught in a bout of colic - the baby or those trying to help him. For anyone fortunate enough to not know what we're talking about here, colic is a condition in which a baby has regular, often predictable, episodes of intense crying that last anywhere from several minutes to several hours. It typically begins when the baby is a few weeks old and can continue for several months.

The frustrating thing is that the child can be well-fed, well-rested, in a clean diaper and in a comfortable environment. Then suddenly she or he will be in profound and prolonged distress. The crying is often high-pitched, accompanied by clenched fists, tensed-up stomach muscles and a defensive, curled-up posture. The level of discomfort is such that comforting a colicky baby can seem all but impossible.

A new study has good news for parents of colicky babies. It appears that a certain probiotic that is already being marketed as a treatment for colic can, in fact, be effective. Known as Lactobacillus reuteri, this species of probiotic has been shown to exhibit antimicrobial activity. And while various small studies have already pointed to Lactobacillus reuteri as a hedge against colic, this latest study backs up the claim for the probiotic with a larger and broader sample size.

Researchers looked at the raw data collected from babies who had been enrolled in four different clinical trials. The stated purpose of these clinical trials had been whether Lactobacillus reuteri was effective in reducing the distress of colicky babies. In these trials, half of the infants with colic received the probiotic, and half received a placebo. The babies were then monitored for outcomes that included how long each baby spent crying during a bout of colic, the degree of fussing that took place, and whether or not the colic symptoms had resolved after three weeks of treatment.

According to the findings, the group taking the probiotic spent measurably less time less crying and fussing than did the babies in the group that received the placebo group. But - and this is important - researchers were only able to confirm the positive effect of the probiotic among babies who were exclusively breast-fed. This was because there were not enough formula-fed infants in the clinical trials to generate sufficient data from which to draw conclusions.

The bottom line: This is a promising avenue of treatment for breast-fed babies with colic. We suggest that parents who want to give it a try (Lactobacillus reuteri is widely available as an over-the-counter product) do so in partnership with their pediatricians.

• Eve Glazier, M.D., MBA, is an internist and assistant professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and primary care physician at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.