The frequent spitting up experienced by babies is a common concern for parents seeking relief. Gastroesophageal Reflux (GER) is the medical term for the backward flow of stomach contents into the esophagus, often manifesting as non-forceful regurgitation or “spit-up.” This process is widespread in infants, generally peaking between four and five months of age before resolving naturally in most babies by the time they are a year old. As parents seek gentle interventions, the role of probiotics—live beneficial bacteria—has become a growing area of interest. This article explores the scientific basis and current evidence regarding the effectiveness of probiotics in addressing infant reflux.
Understanding Infant Acid Reflux
Infant reflux, or GER, occurs because the lower esophageal sphincter (LES) muscle, which functions as a one-way valve between the esophagus and the stomach, is still immature in newborns. This muscle relaxes at inappropriate times, allowing the liquid stomach contents, mixed with acid, to move back up. The frequency of these episodes is also contributed to by the fact that infants spend a large portion of their day lying down and consume an entirely liquid diet.
The condition is considered Gastroesophageal Reflux Disease (GERD) only when the reflux causes bothersome symptoms or complications, such as poor weight gain, feeding refusal, excessive irritability, or respiratory problems like wheezing. Simple spitting-up is defined as GER, whereas GERD suggests a more serious condition. Most infants with GER do not require treatment as the condition typically disappears as their digestive tract matures.
How Probiotics Influence Infant Gut Health
Probiotics are live microorganisms that contribute to a balanced infant gut microbiome, the community of microbes residing in the digestive tract. An imbalance in this microbial community is thought to contribute to various functional gastrointestinal disorders, including symptoms often associated with reflux.
One primary mechanism by which probiotics may help with reflux is by accelerating gastric emptying, the rate at which food leaves the stomach. A faster emptying time reduces the volume and pressure in the stomach, lessening the likelihood of reflux episodes. Certain probiotic strains may also reduce visceral hypersensitivity, decreasing the infant’s perception of pain or discomfort from stomach acid. These bacteria also possess anti-inflammatory properties that may modulate inflammation in the digestive tract.
Current Evidence on Probiotics for Reflux
Scientific studies have focused on specific probiotic strains to alleviate infant reflux symptoms, with Lactobacillus reuteri DSM 17938 being the most extensively researched. Studies have demonstrated that administering this strain can significantly reduce the frequency of regurgitation episodes per day in infants with functional GER compared to a placebo group.
This specific strain appears to exert its effect partly by accelerating the gastric emptying rate. The strongest evidence for probiotics in infants, however, centers on functional gastrointestinal disorders other than complicated GERD, particularly infantile colic. A consistent finding is that L. reuteri DSM 17938 reduces crying and fussing time in breastfed infants with colic, a condition that frequently overlaps with reflux symptoms.
While some studies show a reduction in regurgitation frequency, systematic reviews indicate that the overall evidence base is limited by the small size and high variability among the studies. The results suggest that probiotics may offer a non-invasive strategy for managing regurgitation frequency, but they do not universally show a direct benefit for all symptoms of GERD. Other strains, such as Lactobacillus rhamnosus GG and Bifidobacterium breve M-16V, have also been studied for their role in reducing gastrointestinal symptoms associated with colic and reflux.
Safety and Practical Guidance
Probiotics are generally well-tolerated and considered safe for healthy, full-term infants, with few reported adverse effects. The most common mild side effects are temporary digestive disturbances, such as increased gas or slight bloating, as the gut adjusts. Probiotics are classified as dietary supplements, meaning their quality and concentration are not always strictly regulated like medications.
Parents should always consult a pediatrician before introducing any supplement to an infant’s diet. This consultation is particularly important for infants who were born prematurely, have a weakened immune system, or have other existing health conditions, as severe infections have been reported in these high-risk populations. Administration typically involves mixing the drops or powder into a small amount of breast milk, formula, or semi-liquid food, ensuring immediate consumption. Choosing a product where the specific strain and dose have been studied in infants for the intended purpose is recommended.