Researchers studied 75 Korean preschoolers to understand how food choices affect eczema (a skin condition that causes itching and irritation). They found that children with eczema who ate more processed foods and snacks had different types of bacteria in their stomachs compared to healthy kids. These bacteria were linked to worse itching, especially at night, and lower quality of life. Kids who ate less vitamin C had even more of these problematic bacteria. The study suggests that eating healthier foods with more vitamin C might help reduce eczema symptoms in young children by changing the balance of bacteria in their gut.

The Quick Take

  • What they studied: Whether the types of food young children eat affect the bacteria in their stomachs and how severe their eczema becomes
  • Who participated: 75 Korean children ages 3-6 years old: 24 with eczema and 51 without eczema (healthy controls)
  • Key finding: Children with eczema who ate more processed foods and snacks had higher amounts of certain gut bacteria (Dorea and Anaerostipes) that were connected to worse itching and lower quality of life. Children with lower vitamin C intake had more of these problematic bacteria and more severe eczema.
  • What it means for you: Eating less processed food and more foods with vitamin C (like fruits and vegetables) may help reduce eczema symptoms in young children, though more research is needed to confirm this. This is especially important for children who have trouble sleeping due to itching.

The Research Details

This was a cross-sectional study, which means researchers looked at a group of children at one point in time rather than following them over months or years. They compared children with eczema to healthy children to see what was different about their diets and gut bacteria. The researchers used DNA testing to identify which bacteria lived in each child’s stomach and intestines. They also asked families about what their children ate and measured how severe each child’s eczema was using standard medical scoring systems. They looked at dietary patterns by grouping foods into two main categories: a Traditional Korean diet (with whole foods) and a Processed Food and Snack diet (with packaged and fried foods).

This approach is important because it helps researchers understand the connection between three things: what we eat, the bacteria in our gut, and skin health. By comparing children with and without eczema, scientists can identify patterns that might explain why some children have worse eczema. Understanding these connections could lead to simple dietary changes that help children feel better without needing more medications.

This study has some strengths: it used scientific DNA testing to identify bacteria accurately, and it measured eczema severity using established medical tools. However, the study is relatively small (only 24 children with eczema) and only looked at Korean children, so results may not apply to all populations. Because it’s a cross-sectional study, we can’t prove that diet causes the bacteria changes or eczema—we can only see that they’re connected. The study was done at one point in time, so we don’t know if these patterns stay the same over time.

What the Results Show

Children with eczema who ate more processed foods and snacks had higher amounts of two types of bacteria called Dorea and Anaerostipes in their guts. These bacteria were strongly associated with worse nighttime itching that disturbed sleep and lower quality of life scores. The connection was statistically significant, meaning it’s unlikely to be due to chance alone. Children with eczema who ate less vitamin C had even more Anaerostipes bacteria and showed more severe eczema on two different severity scales (EASI and SCORAD). The vitamin C connection was particularly strong, with children eating the least vitamin C having the most bacteria and worst eczema symptoms.

Dorea bacteria were specifically linked to daytime itching in children with eczema. The Traditional Korean diet pattern (with whole foods) was associated with better outcomes compared to the Processed Food and Snack diet. Children with eczema who followed healthier eating patterns had better quality of life scores overall, suggesting that diet affects not just physical symptoms but also how much eczema impacts daily activities and sleep.

Previous research has shown that gut bacteria play a role in eczema in babies and infants, but this is one of the first studies to carefully examine this connection in preschool-aged children. The findings support the growing scientific understanding of the ‘diet-gut-skin axis’—the idea that what we eat changes our gut bacteria, which then affects skin health. This study adds to evidence that vitamin C and processed foods may be particularly important factors in childhood eczema.

The study is relatively small with only 24 children with eczema, which limits how much we can generalize the findings. All participants were Korean, so results may not apply to children from other ethnic backgrounds who have different traditional diets. The study only looked at one point in time, so we can’t determine if dietary changes actually cause improvements in eczema or if children with worse eczema simply eat differently. The study couldn’t prove cause-and-effect, only that these factors are associated. More research with larger groups and longer follow-up periods is needed to confirm these findings.

The Bottom Line

For parents of children with eczema: Consider reducing processed foods and snacks and increasing foods rich in vitamin C (oranges, strawberries, bell peppers, broccoli) with moderate confidence. This dietary change appears safe and may help reduce itching and improve sleep quality. Discuss any major dietary changes with your child’s doctor, especially if your child has other food allergies or sensitivities. These findings suggest dietary modification may be a helpful addition to other eczema treatments, not a replacement for them.

Parents and caregivers of preschool children (ages 3-6) with eczema should pay attention to these findings. Children with eczema that causes significant itching or sleep problems may benefit most. Healthy children without eczema may also benefit from eating less processed food and more vitamin C-rich foods for overall health. Healthcare providers treating childhood eczema should consider asking about dietary patterns as part of their assessment.

Changes in gut bacteria can begin within days to weeks of dietary changes, but noticeable improvements in eczema symptoms typically take 2-4 weeks to become apparent. Sleep disturbance from itching may improve sooner if dietary changes help reduce nighttime itching. Full benefits may take 6-8 weeks to become obvious. Individual children may respond differently, so patience and consistency are important.

Want to Apply This Research?

  • Track daily processed food and snack intake (servings per day) alongside eczema itching severity (rate nighttime itching on a 1-10 scale) and sleep quality (hours slept, number of nighttime awakenings). Monitor weekly vitamin C intake through foods like citrus fruits, berries, and vegetables.
  • Replace one processed snack per day with a vitamin C-rich whole food (apple with almond butter, orange slices, or carrot sticks). Gradually increase the number of home-cooked meals using whole ingredients. Track which specific food swaps seem to reduce itching most for your child.
  • Create a simple weekly log showing: (1) percentage of meals that are home-cooked vs. processed, (2) daily vitamin C servings, (3) average nighttime itching score, and (4) sleep quality. Look for patterns over 4-8 week periods to see if dietary improvements correlate with better eczema control. Share this data with your child’s healthcare provider to guide treatment decisions.

This research suggests associations between diet, gut bacteria, and eczema severity in preschool children, but does not prove that dietary changes will cure or eliminate eczema. This study was conducted in Korean children and results may not apply to all populations. Always consult with your child’s pediatrician or dermatologist before making significant dietary changes, especially if your child has food allergies, other medical conditions, or takes medications. Dietary modification should complement, not replace, medical treatment prescribed by healthcare providers. Individual results vary, and what works for one child may not work for another.