Can probiotics help with infant colic?

At Onoco, we’re always on the lookout for new research that can help parents better understand and navigate the challenges of early parenting. We came across this recent study and found it particularly interesting, so we decided to share it with our community.

In a small randomized trial (n=68) published in the European Journal of Pediatrics (2025), a multistrain synbiotic (probiotics + prebiotic) was associated with faster improvements in caregiver quality of life and reductions in crying episodes/time over 4 weeks. One daily dose performed similarly to two, and improvements appeared within 7 days. The study was open access under CC BY 4.0, so we reproduce key figures below with attribution.

What is a synbiotic?

A synbiotic is a combination of probiotics (live beneficial microorganisms, such as Lactobacillus or Bifidobacterium) and prebiotics (non-digestible food components, often fibers, that serve as nourishment for those beneficial bacteria). When used together, synbiotics aim to improve the balance of gut bacteria more effectively than either component alone.

The International Scientific Association for Probiotics and Prebiotics (ISAPP) defines synbiotics as “a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host.” (Swanson et al., Nat Rev Gastroenterol Hepatol 2020.)

In infants, the goal of synbiotic supplementation is to promote a healthy gut microbiome early in life, potentially reducing inflammation, gas production, and discomfort associated with colic.

Why this matters for parents

Infantile colic—recurrent, prolonged periods of crying/fussing in otherwise healthy infants—affects a sizable minority of families and can be extremely stressful. Although most cases resolve by ~5 months, even a few weeks of intense crying can impact parent sleep, mental health, and confidence. Safe, evidence-based options that may ease symptoms are therefore important.

The study at a glance

Design: Randomized trial, intention-to-treat analysis.

Participants: 68 full-term infants, 2–8 weeks old, presumed healthy, any feeding mode (breast, mixed, formula).

Intervention: Bactecal D Liquid® once daily vs twice daily for 28 days.

Primary outcome: Caregiver quality of life (QoL) on a 1–7 Likert scale.

Secondary outcomes: Number of crying episodes, total crying time, gassiness, and “balling of the fists.”

Registration & ethics: NCT05052476; approved by UZ Brussel EC; conducted 2022–2023.

Are probiotics for colic effective? What were the results

QoL improved quickly and substantially. Median caregiver QoL rose from 2 (1–3) at baseline to 6 (5–7) by day 28 (p < 0.001). Improvement was already significant at day 7.

Dose mattered less than expected. Two doses were not more effective than one at any time point.

Across feeding modes. In post-hoc models, feeding type (breast, mixed, formula) wasn’t associated with different QoL improvements.

Crying metrics improved. Both the number of episodes and total crying time decreased over 4 weeks.

Key charts from the paper

Figure 1. Evolution of quality of life scores during the treatment period.

Figure 2. Percentage of caregivers with QoL > 4 by visit day.

Source for Figures 1–2: Delcourt H, Huysentruyt K, Vandenplas Y. A synbiotic mixture for the management of infantile colic: A randomized trial. Eur J Pediatr. 2025;184:27. Licensed under CC BY 4.0.

How does this fit with what we already know?

Colic definitions have evolved. While the old “Rule of Three” (3 hours, 3 days/week, 3 weeks) is well known, the study focuses on recurrent, prolonged crying/fussing without another disease explanation and is often used in research.

Microbiome-based approaches show promise. Prior trials and meta-analyses suggest certain probiotics—especially Lactobacillus reuteri DSM 17938—may reduce crying in breastfed infants; evidence in formula-fed infants has been less consistent. The present synbiotic trial extends this area, reporting improvements regardless of feeding mode.

Risk factors exist, but mechanisms are unclear. Recent cohort work highlights multifactorial early-life risk factors (e.g., prematurity, maternal factors), and reviews note possible links to later functional GI symptoms and even migraines—but causality remains unproven.

Limitations to keep in mind

No placebo arm. The trial compared once-daily vs twice-daily synbiotic, not synbiotic vs placebo, so we can’t fully separate treatment effects from natural improvement and supportive care.

Sample size was modest (n=68) and not powered for subgroup analyses.

Outcomes relied on caregiver-reported measures; objective crying measurements are challenging but would strengthen future work.

Short follow-up (28 days); longer-term outcomes are unknown.

Practical takeaways for families using Onoco

If your baby meets typical colic patterns, structured tracking and supportive routines still matter most: safe soothing techniques, caregiver breaks, and sleep hygiene. You can use the Onoco app to log crying episodes and naps—objective patterns help your care team.

Synbiotics are an option to discuss with your pediatric clinician. Product quality varies; your clinician can help you choose evidence-based brands and dosing.

Watch for red flags (fever, poor feeding/weight gain, bilious vomiting, lethargy, or signs of illness). These are not colic and require prompt medical evaluation.

References & further reading (open/official sources)

1. Delcourt H, Huysentruyt K, Vandenplas Y. A synbiotic mixture for the management of infantile colic: A randomized trial. Eur J Pediatr. 2025;184:27. doi:10.1007/s00431-024-05860-5. (Open access, CC BY 4.0).

2. Swanson KS, et al. ISAPP consensus statement on the definition and scope of synbiotics. Nat Rev Gastroenterol Hepatol. 2020;17(11):687–701.

3. Rome Foundation. Rome IV Diagnostic Criteria for Infant Colic. (Clinical research definition and criteria.)

4. Sung V, et al. Lactobacillus reuteri DSM 17938 to treat infant colic: meta-analysis. Pediatrics. 2018;141(1):e20171811.

5. Indrio F, et al. Infantile Colic and Long-Term Outcomes in Childhood. Nutrients. 2023;15(3):615.

6. Switkowski KM, et al. Early-life risk factors for infant colic and excessive crying. Pediatric Research. 2025;97(5):1537–1545.