Researchers wanted to know if kefir, a fermented milk drink full of healthy bacteria, could help children with ADHD feel better and sleep more soundly. They gave 53 kids either kefir or a fake drink for six weeks and tracked their ADHD symptoms, sleep patterns, and gut bacteria. While kefir didn’t dramatically reduce ADHD symptoms overall, kids who drank kefir did spend less time awake during sleep time according to movement tracking devices. The study suggests kefir might help with sleep quality, though the results were modest and more research is needed to understand how it works.

The Quick Take

  • What they studied: Whether drinking kefir daily could reduce ADHD symptoms, improve sleep, and change the types of bacteria living in children’s stomachs.
  • Who participated: 53 children between ages 8-13 years old who had been diagnosed with ADHD. The average age was about 10 years old. Half got kefir to drink daily, and half got a placebo (fake) drink that looked and tasted similar.
  • Key finding: Kefir didn’t significantly reduce ADHD symptoms overall. However, kids drinking kefir showed less time awake during sleep periods (70 minutes vs. 90 minutes), suggesting better sleep quality. Interestingly, kids who reported their own sleep said they had more sleep problems after drinking kefir, which contradicts the movement tracking data.
  • What it means for you: Kefir may help children with ADHD sleep a bit better based on objective measurements, but the evidence is still weak and mixed. This is early-stage research, so don’t expect kefir to be a cure for ADHD. Talk to your doctor before making dietary changes for ADHD management.

The Research Details

This was a randomized controlled trial, which is considered one of the strongest types of research studies. Researchers randomly assigned children to either drink kefir or a placebo drink every day for six weeks. Neither the children, parents, nor researchers knew who was getting the real kefir and who was getting the fake drink—this is called “double-blind” and helps prevent bias. The study measured ADHD symptoms using teacher and parent questionnaires, tracked sleep using special wristbands that detect movement, and analyzed the bacteria in children’s stool samples using advanced genetic testing.

The double-blind, randomized design is important because it helps prove that any changes are actually caused by the kefir and not by expectations or other factors. By measuring sleep with both movement trackers and self-reports, researchers could compare objective data with what kids actually felt. Testing the gut bacteria directly allowed researchers to see if kefir changed the bacterial community, which might explain any symptom improvements.

This study has several strengths: it was properly randomized, double-blinded, and published in a peer-reviewed medical journal. However, the sample size of 53 children is relatively small, which means results might not apply to all children with ADHD. The study only lasted six weeks, so we don’t know if benefits would continue longer. The conflicting sleep results (movement trackers showed improvement, but kids reported worse sleep) raise questions about what’s really happening.

What the Results Show

Kefir did not significantly reduce ADHD symptoms as measured by parent or teacher ratings. This was the main goal of the study, and it didn’t work out as hoped. However, there was a hint that children who started with the most severe ADHD symptoms might have improved slightly more in the kefir group compared to placebo, though this difference wasn’t quite statistically significant (p = 0.088, meaning there’s about a 9% chance this happened by random luck). The researchers also looked at attention and impulse control using a computer test, and found a near-significant trend suggesting kefir might help with attention consistency, but again, this wasn’t a clear win.

The most interesting finding was about sleep. Movement tracking devices showed that children in the kefir group spent about 20 fewer minutes awake during their sleep period (70 minutes vs. 90 minutes), which was statistically significant. This suggests kefir might genuinely improve sleep quality. However, this contradicts what the children themselves reported—kids in the kefir group actually reported more sleep problems after the study ended. The study also found that kefir increased several types of healthy gut bacteria, including bifidobacterium species, which are known to be beneficial. However, these bacterial changes didn’t clearly connect to symptom improvements.

Previous research suggested that children with ADHD might have different gut bacteria compared to children without ADHD, leading scientists to hypothesize that changing the gut bacteria might help symptoms. This study is one of the first to test this idea with kefir in children with ADHD. The results are more modest than some researchers hoped, but they align with other studies showing that gut health interventions have complex effects that aren’t always straightforward.

The study was only six weeks long, which might not be enough time to see major changes in ADHD symptoms. The sample size of 53 children is small, making it harder to detect real effects. The conflicting sleep results (objective vs. self-reported) are confusing and hard to interpret. The study didn’t follow children after the intervention ended, so we don’t know if any benefits lasted. Additionally, the study was conducted only in the UK with a specific population, so results might not apply to all children with ADHD worldwide.

The Bottom Line

Based on this research, kefir is not recommended as a primary treatment for ADHD symptoms. However, if a child with ADHD is struggling with sleep, kefir might be worth trying as a complementary approach (alongside other treatments), with medical supervision. The evidence is still weak (confidence level: low to moderate), so this should not replace standard ADHD treatments like medication or behavioral therapy. Always consult with a pediatrician or ADHD specialist before making dietary changes.

Children with ADHD who also have sleep problems might benefit from exploring kefir as an additional tool. Parents and caregivers of children with ADHD should be aware of this research but shouldn’t expect it to replace proven treatments. Healthcare providers working with children with ADHD should know about this emerging research. People without ADHD or without sleep problems probably won’t see benefits from kefir for ADHD-related reasons.

In this study, any sleep improvements appeared within six weeks. However, changes in gut bacteria might take longer to develop fully. Realistic expectations: if kefir helps, you might notice subtle sleep improvements within 4-6 weeks, but don’t expect dramatic changes in ADHD symptoms. It typically takes several weeks of consistent use to see any effects.

Want to Apply This Research?

  • Track sleep quality using the app’s sleep log feature. Record: (1) minutes spent awake during sleep periods using a wearable device if available, (2) subjective sleep quality rating (1-10 scale), and (3) morning alertness level. Compare these metrics weekly while taking kefir to establish if there’s a personal benefit.
  • Add a daily kefir serving (one small glass or serving size) at the same time each day, preferably in the morning or early afternoon. Log this in the app as a daily habit to track consistency. Note any changes in sleep patterns, mood, or focus over the six-week period.
  • Create a 6-week tracking protocol: weekly ADHD symptom check-ins using simple parent/self-rating scales, daily sleep quality logs, and weekly gut health notes (digestive comfort, energy levels). Use the app’s trend analysis to compare baseline measurements with week 6 measurements. If no improvement appears after 6 weeks, discuss with a healthcare provider about continuing or trying other approaches.

This research is preliminary and should not replace standard ADHD treatments prescribed by healthcare providers. Kefir is a food supplement, not a medication, and has not been proven to treat ADHD symptoms. Some children may have allergies or intolerances to kefir (especially if lactose intolerant or allergic to dairy). The conflicting sleep results in this study suggest the effects are complex and may vary by individual. Always consult with a pediatrician, psychiatrist, or ADHD specialist before making dietary changes for ADHD management, especially if your child is taking medications. This summary is for educational purposes and does not constitute medical advice.