by Dr. Jonathan Goldfinger, MD, MPH, FAAP, Chief Medical Officer, HealthySteps, ZERO TO THREE
Colic is a common, distressing experience for parents. The intense, frequent, and prolonged crying, seemingly for no reason, can be very upsetting. Depending on the study, anywhere from 8–40% of babies and their parents go through this. Many experience what my parents once described as chauffeuring my screaming older brother around town for endless nights until he fell asleep.
Treating Colic With Lactobacillus
As common as colic is, there is little agreement on how to manage it. So it was no surprise when a new study titled Lactobacillus reuteri to Treat Infant Colic: A Meta-analysis by Valerie Sung and colleagues was published in a recent issue of the journal Pediatrics and the accompanying commentary read, Is It Time To Recommend Lactobacillus for Colic? Not Necessarily. Years addressing newborn and parent well-being in a primary care breastfeeding clinic led me to similarly promising, yet rebutted studies.
In their meta-analysis, Sung and colleagues provided a compelling case for using Lactobacillus, a naturally occurring gut bacterium (aka a “probiotic”), to treat infant colic. Their high-quality study design combined data on 345 infants with colic (174 given probiotics and 171 placebos) from four double-blinded trials. Infants in all four studies received the same doses of probiotic and placebo. No study reported adverse events.
The authors found that babies on probiotics had significantly less “crying and/or fussing” at 1 week, 2 weeks, and 3 weeks after taking it, with the greatest difference—approximately 25 minutes less crying and/or fussing per day—noted at 3 weeks. Those who received probiotics were nearly twice as likely to have their crying time decrease by half or more at all time points, with breastfed infants 2–3 times more likely, and insignificant change in formula-fed infants.
The commentary noted that the authors limited their analysis to studies of infants outside the United States, including one in which breastfed infants in Australia did not wholly benefit from probiotics. A fair case is made that the developing natural intestinal bacteria (aka the “microbiome”) of breastfed infants within the U.S. might not react as favorably as the microbiome of breastfed infants in other countries. I’ll add another wrinkle—the majority of American infants are still fed formula in latest national data.
Despite these limitations, I believe this is an important study for pediatricians and early childhood professionals to consider when counseling parents. Certainly, newborns at risk of systemic inflammation or immunocompromise (because of premature birth, a recent stay in intensive care, being on a ventilator, or even having the flu or other severe illnesses) should avoid prolonged probiotics. But in otherwise healthy, breastfed babies, this study is as good a reason as any I’ve seen to at least consider probiotics for colic after other proven methods have failed.
I say consider it, rather than making it your first choice, for a number of reasons. First, working closely with lactation and gastrointestinal experts taught me to reserve a healthy skepticism for “consume this and all will be well” nutrition research. The Sung study implies that millions of years of evolution in our babies’ first food (mammals by definition feed via mammary!) and multiple natural paths to seeding newborn intestinal flora may still need our help. We know healthy exposure to bacteria starts in the birth canal, continues with skin-to-skin contact with parents and caregivers, and occurs through breastfeeding. So it feels odd that infants who exclusively go through this natural nurturing process may need even more of a certain bacteria to cry less distressingly.
I can think of other reasons to pause. No one has found a unifying or consistent explanation for colic. I believe the theory that says it’s because colic is likely different things in each case. In residency I was taught that researchers find a plausible etiology in less than half of colic cases, and the majority of those tend be discomfort from gastroesophageal reflux or gas. The study’s authors could provide no unifying explanation as to why Lactobacillus would work in all the cases it did.
Because enough cases of colic may be tied to how a baby is being fed, prudence would dictate that professionals should be offering all parents tried and true feeding interventions first and foremost. Backed by research, my colleagues and I frequently found in our breastfeeding clinic that adjusting latch technique, positioning the infant upright both during and after feeds (breast or bottle), and pacing feeds with smaller more frequent meals all helped. In addition, soothing techniques such as warm baths, pacifiers, car or stroller rides, baby carriers, rocking or massage, and soothing heart-sounds or white noise at low decibels, have been shown to help, and are equally harmless.
Last and never least, primum non nocere. Currently, society tends to think of probiotics as harmless, but I wonder whether ever-present food crazes, from kombucha to kimchi, influence these beliefs and desires more than real research. I counsel parents who’ve exhausted their options or really want to try Lactobacillus that, although it is likely safe and may help, there are no long-term follow-up studies on its use in babies. Researchers still don’t know whether changing a baby’s natural gut bacteria may somehow risk early intestinal inflammation and thereby trigger autoimmune disorders. There is enough research on potential mechanisms for intestinal inflammatory cascades leading to asthma, allergies, diabetes, and even heart disease years later.
Don’t get me wrong. Excellent research has been done to show that certain edible bacteria are healthy for adults (go kimchi!), and I have seen Lactobacillus used successfully and harmlessly in infants for the short-term treatment of antibiotic-caused diarrhea. In fact, research has shown there are “no differences…in stool consistency, flatulence, fussiness, or adverse events” when typical infants are given varying doses of the bacteria, or none at all, in their formula.
A Different and Needed Approach: Addressing the Social Context of Colic
I also wonder whether colic is somehow adaptive, such that we shouldn’t rush to extinguish it. Colic has been associated with first-born babies, and babies of mothers with depression, anxiety, and high levels of stress. A mainstay of treatment is therefore to address the needs and well-being of new parents, including how they react when a baby is crying. Instead of pathologizing babies with colic, professionals should work to ensure parents have protective factors, such as social supports and parenting knowledge, to help them weather the storm.
Having had a first-born with colic after my wife suffered multiple stressors during her pregnancy, this last point really speaks to me. I’ve often thought that the breastmilk of mothers who remain under duress may somehow trigger (or maintain) colic in infants whose rapidly developing brains were predisposed to these stressors in the womb or shortly after birth. There may also be triggers in the way stressed, exhausted parents interact with colicky infants, leading to a vicious cycle.
Real research shows that social triggers can be modified through parenting programs such as ZERO TO THREE’s HealthySteps model. In one clinical trial, parents of colicky infants who were counseled regarding effective responses to crying saw crying decrease from 2.6 to 0.8 hours a day. That’s about 4 times the effectiveness of giving Lactobacillus in Sung’s study! In another randomized trial, crying decreased twice as much when parents received parenting counselling as it did when mothers changed their diets. (Mom’s diets causing breastfed babies problems is more myth than reality.)
Additional research connecting both the biological and social underpinnings of colic, and how professionals and families might address them together, is still needed to be able to “put this baby to rest.” For now, I recommend connecting families with trustworthy resources on colic such as the AAP’s HealthyChildren.org and ZERO TO THREE.org, and proven feeding and parenting supports. In the end, all parents can be reassured that colic will die down by 3 to 4 months and be gone by 6 months. That, and perhaps kimchi, should help all sleep just a little better as new parents.
Dr. Jonathan Goldfinger, MD, MPH, FAAP, is Chief Medical Officer for HealthySteps and ZERO TO THREE, and a loving father to 6-month-old and 3-year-old boys. This piece reflects his personal and professional views, with links to published research expressing that of the stated author. This is in no way a reflection of the recommendations or position of HealthySteps or ZERO TO THREE.