Probiotics For Infant Colic: One Finding Surprised Experts
Recent evidence on infant colic
The latest clinical evidence suggests that probiotics can reduce crying time in some infants with colic, but the benefit is inconsistent by feeding type and strain, and the certainty of the evidence remains low to moderate overall. The most notable recent finding is that breastfed infants appear more likely to benefit than formula-fed infants, and the best-studied strain, Lactobacillus reuteri DSM 17938, continues to show the strongest signal in trials and meta-analyses.
Recent reviews also show a split result: probiotics may not prevent infant colic in healthy newborns, yet they may still shorten daily crying once colic is present. That distinction matters, because prevention studies and treatment studies answer different clinical questions and can point in opposite directions.
What the studies found
In a 2024 systematic review and meta-analysis published in Acta Paediatrica, researchers pooled randomized controlled trials of probiotics and synbiotics for infantile colic and found an average reduction of about 51 minutes of crying per day overall. The same review reported a larger reduction in exclusively breastfed infants, while evidence in formula-fed and caesarean-born infants remained limited.
A Cochrane review updated in 2025, focused on prevention, found that probiotics made little or no difference to whether colic developed, but they may reduce crying time and did not raise clear safety concerns. That combination of findings is why clinicians now tend to describe probiotics as potentially useful for symptom reduction in selected infants rather than as a universal solution.
| Study | Year | Population | Main finding |
|---|---|---|---|
| Acta Paediatrica meta-analysis | 2024 | Infants under 3 months with colic | About 51 minutes less crying per day overall; stronger effect in breastfed infants |
| Cochrane prevention review | 2025 | Healthy newborns given probiotics | Little or no effect on colic occurrence, but crying time may fall |
| Earlier pooled RCT evidence | 2018 and later updates | Mixed infant feeding patterns | Signal strongest for Lactobacillus reuteri DSM 17938 in breastfed infants |
The surprising finding
The finding that surprised many experts is that probiotics do not seem to work equally well across all infants, even when the same general diagnosis of colic is used. The response appears to depend on whether the infant is exclusively breastfed, which suggests that the infant gut environment and milk composition may influence how probiotics act.
That pattern is clinically important because it means a treatment can look modest overall while still being quite relevant for a subgroup. In practical terms, a breastfed infant with persistent colic may be a more plausible candidate for a probiotic trial than a formula-fed infant, based on current evidence.
Most studied strains
Across recent trials, the most frequently studied organism has been Lactobacillus reuteri DSM 17938, with several studies also examining multispecies formulations and other Lactobacillus or Bifidobacterium strains. The most consistent evidence remains with Lactobacillus reuteri DSM 17938, although newer analyses suggest that multiple strains may have some benefit in certain settings.
- Lactobacillus reuteri DSM 17938: the best-known strain for infant colic research, especially in breastfed infants.
- Multistrain probiotics: studied less often, with promising but less consistent findings.
- Bifidobacterium-containing products: biologically plausible, but evidence is less robust than for L. reuteri.
- Synbiotics: probiotic-plus-prebiotic products have been tested, but the evidence base is still thin.
Why the results differ
One reason the results are mixed is that infant colic is not one single biological disorder. It is a clinical syndrome with multiple possible contributors, including gut microbiome differences, feeding practices, immature digestion, and early-life stress responses. That means the gut microbiome may be important in some infants but not in others.
Trial design also matters. Studies differ in the age at which treatment starts, the dose used, the length of follow-up, and the way crying is measured. When those variables vary, pooled results can look less precise even when a real biological effect exists.
Safety and limitations
Across the recent reviews, probiotics have not shown a major safety signal in otherwise healthy infants, which is one reason pediatric interest remains high. Still, the evidence base is not strong enough to say all products are interchangeable, and product quality can vary substantially from one brand to another.
There are also important limits to the evidence. Most trials are small, many use different endpoints, and the certainty of evidence is often rated low because the studies are heterogeneous. That means the current data are encouraging but not definitive.
"The evidence points to a real possibility of benefit, but not a blanket recommendation for every infant with colic."
How clinicians use this today
In practice, many clinicians treat probiotics as a short, monitored trial rather than a guaranteed fix. A reasonable approach is to consider them in an infant with typical colic who is otherwise healthy, especially if the infant is breastfed and the family wants to try a low-risk intervention. The key phrase here is time-limited trial, because ongoing use without measurable improvement is unlikely to help.
- Confirm the crying pattern fits infant colic rather than another medical problem.
- Check feeding history, growth, and any warning signs such as fever, vomiting, poor weight gain, or blood in stool.
- If appropriate, choose a studied strain rather than an untested "baby probiotic" label.
- Track crying time and feeding for 1 to 2 weeks to see whether there is a meaningful response.
- Stop the product if there is no clear benefit or if any concerning symptoms appear.
What parents should know
Parents looking at the recent research should know that probiotics are not a cure-all, but they may help some babies, especially those who are breastfed. The strongest evidence supports a reduction in crying time, not a guaranteed elimination of colic. In other words, the outcome is often less crying, not necessarily no crying.
It is also important to separate normal developmental crying from signs of illness. Colic is usually diagnosed when a baby is otherwise healthy but has repeated episodes of intense crying that are difficult to soothe. Persistent vomiting, poor feeding, lethargy, fever, or poor growth should prompt medical evaluation rather than a probiotic trial.
Practical takeaway
The newest studies suggest a nuanced answer: probiotics may help reduce crying in infant colic, but the benefit is not uniform and appears strongest in breastfed babies. The most surprising and clinically useful lesson is that a probiotic can be promising without being broadly effective for every infant.
For parents and clinicians, the evidence now supports cautious optimism, careful product selection, and realistic expectations. For researchers, the next step is better strain-specific trials, more formula-fed infant data, and longer follow-up to determine which babies benefit most from targeted therapy.
Key concerns and solutions for Probiotics For Infant Colic One Finding Surprised Experts
Do probiotics prevent infant colic?
Current evidence says probiotics do little or nothing to prevent colic in healthy newborns, although they may still reduce crying time once symptoms are present. That is the main distinction between the prevention literature and the treatment literature.
Which probiotic strain has the best evidence?
Lactobacillus reuteri DSM 17938 has the most consistent research support, especially in breastfed infants. Other strains and multistrain products have been studied, but the evidence is less uniform.
Are probiotics safe for babies with colic?
Recent reviews have not found a major safety signal in healthy infants, and serious adverse effects appear uncommon. Even so, the exact product matters, and babies with medical problems should be assessed by a clinician before any supplement is used.
Should all colicky infants take probiotics?
No. The best current evidence supports selective use rather than universal use, because benefits seem to vary by feeding type, strain, and study design. A monitored trial is more evidence-based than routine use for every infant.