Researchers tested whether special bacteria called probiotics could help children recover faster from diarrhea. They gave 141 children either probiotics, a fake treatment, or just standard care for a month. While the probiotics did change the bacteria in kids’ stomachs in good ways, they didn’t actually make diarrhea go away any faster than regular treatment alone. The study suggests probiotics might help restore healthy gut bacteria, especially when kids are taking antibiotics, but they’re not a magic cure for diarrhea.

The Quick Take

  • What they studied: Whether giving children special healthy bacteria (probiotics) alongside normal diarrhea treatment would help them feel better faster and restore their gut health
  • Who participated: 141 children between 6 months and 6 years old who had diarrhea. They were randomly split into three groups: one got probiotic bacteria, one got a fake treatment that looked the same, and one got standard care only
  • Key finding: Probiotics did change the gut bacteria in positive ways—they increased good bacteria and reduced harmful bacteria. However, children taking probiotics didn’t recover from diarrhea any faster than children who didn’t take them
  • What it means for you: While probiotics appear safe and may help restore healthy gut bacteria (especially important if your child is on antibiotics), they shouldn’t be relied on as the main treatment for diarrhea. Standard care like fluids and electrolytes remains most important. Talk to your doctor before giving probiotics to young children

The Research Details

This was a high-quality study called a randomized controlled trial, which is considered one of the best ways to test if a treatment works. Researchers divided 141 children with diarrhea into three groups randomly—like drawing names from a hat. One group received Limosilactobacillus reuteri (a type of helpful bacteria), another got Bifidobacterium breve (another helpful bacteria), and the third group got a placebo (fake treatment that looked identical). Nobody knew which group they were in, which helps prevent bias. All children also received standard diarrhea care.

The researchers tracked the children for one month and tested their gut bacteria before and after using advanced lab techniques. They looked at the types and amounts of bacteria living in each child’s stomach and intestines. They also watched how long the diarrhea lasted and how the children felt overall.

This study design is important because it helps prove whether probiotics actually work, not just whether they seem to help. By comparing probiotics to a fake treatment, researchers can see if any improvement comes from the probiotics themselves or just from regular treatment and time. Testing the actual bacteria in the gut shows what’s happening inside, even if kids don’t feel better faster

This study has several strengths: it was double-blind (neither doctors nor families knew who got real probiotics), it had a control group for comparison, it used advanced lab testing to measure changes, and it was published in a respected science journal. The main limitation is that 141 children is a moderate sample size—larger studies might show different results. The study only lasted one month, so we don’t know about longer-term effects

What the Results Show

All three groups of children showed improvement in their gut bacteria diversity, meaning their stomachs developed a wider variety of bacteria—which is generally healthy. However, the children who received probiotics showed more growth of the specific good bacteria they were given (Limosilactobacillus and Bifidobacterium).

Harmful bacteria called Clostridioides difficile decreased in all groups, even those who didn’t get probiotics. This suggests that standard diarrhea care and time naturally help restore healthy bacteria.

The most interesting finding was in children taking antibiotics: only the probiotic groups showed significant changes in their gut bacteria. This suggests probiotics might be especially helpful when antibiotics are killing off all bacteria, both good and bad.

However, when researchers looked at what really matters—how long diarrhea lasted and how sick the children felt—there were no meaningful differences between the groups. Children with probiotics didn’t recover faster or feel better than children without them

The study found that probiotics were safe and well-tolerated in young children. There were no serious side effects reported. The probiotics successfully colonized (took hold in) the children’s guts, meaning the bacteria survived and grew. This shows the probiotics actually reached where they needed to go

Previous research has been mixed about probiotics for diarrhea in children. Some older studies suggested benefits, but many were smaller or had weaker designs. This study’s finding—that probiotics change gut bacteria but don’t speed recovery—suggests that earlier positive results might have been due to other factors like placebo effect or standard care. The results align with recent reviews suggesting probiotics have limited clinical benefit for acute diarrhea

The study only lasted one month, so we don’t know if benefits appear later. The researchers only tested two specific probiotic strains—other types might work differently. The study included children from 6 months to 6 years, a wide age range where responses might differ. We don’t know how results would differ in children with severe diarrhea or specific causes like rotavirus. Finally, the study didn’t track what children ate or other factors that might affect gut bacteria

The Bottom Line

Based on this research, probiotics are not recommended as a primary treatment for childhood diarrhea (moderate confidence). Standard care—keeping children hydrated with fluids and electrolytes—remains most important. Probiotics may be considered as an addition to standard care, particularly if your child is taking antibiotics, but don’t expect them to speed recovery (low to moderate confidence). Always consult your pediatrician before giving probiotics to young children, especially infants under 12 months

Parents of children with diarrhea should care about this research, especially those considering probiotics. Pediatricians should use this to counsel families that probiotics aren’t a replacement for standard care. Children taking antibiotics might benefit most from probiotics, though the clinical advantage is unclear. This research is less relevant for adults, as children’s developing gut bacteria may respond differently

If you do use probiotics, changes in gut bacteria may appear within days to weeks, but symptom improvement shouldn’t be expected. Diarrhea typically resolves on its own within 3-7 days with proper hydration, regardless of probiotics. Don’t wait for probiotics to work—focus on keeping your child hydrated and contact your doctor if diarrhea lasts more than a week or worsens

Want to Apply This Research?

  • Track diarrhea duration (number of days until normal stools return) and daily hydration intake (cups of fluids consumed) rather than expecting probiotics to show measurable improvements. Note any antibiotic use, as this context matters for probiotic effectiveness
  • If using probiotics, set a daily reminder to give them at the same time each day to ensure consistency. More importantly, establish a hydration tracking habit—log water, broth, or electrolyte drinks given to your child every 2-3 hours during diarrhea episodes
  • Create a simple symptom log noting stool frequency and consistency daily. Track any changes in appetite or energy level. If diarrhea lasts beyond 7 days, contact your pediatrician. Use the app to set reminders for follow-up doctor visits rather than relying on probiotics alone to show improvement

This research summary is for educational purposes only and should not replace professional medical advice. Probiotics are not FDA-approved medications and are not intended to diagnose, treat, cure, or prevent any disease. Before giving probiotics or any supplement to your child, especially infants under 12 months, consult with your pediatrician. If your child has severe diarrhea, bloody stools, signs of dehydration, fever, or diarrhea lasting more than a week, seek immediate medical attention. Individual results may vary, and this study’s findings may not apply to all children or all types of diarrhea.