Scientists discovered that a type of fiber called inulin may help children with obesity by improving communication between their gut and brain. In a 6-month study with 154 children, those who took inulin supplements showed increases in special brain-supporting chemicals in their blood. These chemicals are made by helpful bacteria in the gut and appear to help the body manage weight better. The study suggests that inulin works by changing which bacteria live in the gut, which then produce more of these helpful brain chemicals. This is exciting because it shows a natural way to support children’s health through their gut bacteria.

The Quick Take

  • What they studied: Whether a fiber supplement called inulin could change the chemicals in children’s blood that help their gut and brain communicate, and whether these changes relate to their gut bacteria.
  • Who participated: 154 children aged 7-15 years old who had obesity. They were split into three groups: one got inulin fiber, one got a fake placebo that looked similar, and one got advice about eating more fiber naturally.
  • Key finding: Children taking inulin showed significant increases in three important brain-supporting chemicals (putrescine, spermine, and tyrosine) after 6 months, while the placebo group did not. The inulin group’s increase in putrescine was 2.6 times stronger than the placebo group.
  • What it means for you: Inulin supplementation may help children with obesity by boosting natural brain-supporting chemicals made by gut bacteria. However, this is early research, and more studies are needed before doctors recommend it widely. Talk to your child’s doctor before starting any supplements.

The Research Details

This was a randomized controlled trial, which is one of the strongest types of research studies. Scientists randomly divided 154 children into three equal groups to make sure the groups were similar at the start. One group took inulin (a special fiber from plants) every day for 6 months, another group took a fake placebo that looked the same but had no inulin, and the third group got advice about eating more fiber naturally. The researchers measured special chemicals in the children’s blood at the beginning and after 6 months using advanced laboratory equipment. They also tested the children’s gut bacteria to see how it changed.

The study was designed to test whether inulin could change the chemicals that help the gut and brain communicate. Scientists focused on amino acids and other molecules that are known to affect brain function and energy balance. They used a technique called principal component analysis, which is like a special computer tool that finds patterns in lots of data at once.

This research approach is important because it looks at the actual biological changes happening inside the body, not just weight loss. By measuring specific chemicals and gut bacteria, scientists can understand the actual mechanism—the ‘how’ and ‘why’—behind how inulin might help with obesity. This is better than just measuring weight, because it shows us what’s actually happening at the microscopic level.

This study has several strengths: it was randomized (which reduces bias), it had a control group (placebo), it lasted 6 months (long enough to see real changes), and it used advanced laboratory methods to measure chemicals accurately. The study was registered before it started, which is a good sign of transparency. However, the study is relatively small (154 children), and we don’t know how long the effects last after stopping the supplement. The results are promising but not yet definitive proof.

What the Results Show

After 6 months, children taking inulin showed marked increases in three important chemicals: putrescine, spermine, and tyrosine. All three increases were highly significant (P < 0.0001, which means there’s less than a 0.01% chance these results happened by accident). In comparison, the placebo group did not show these increases.

The most impressive finding was putrescine, which increased significantly more in the inulin group compared to the placebo group (P = 0.021). This is important because putrescine is a chemical that helps protect brain cells and supports healthy brain function.

The researchers also found that the changes in these brain-supporting chemicals were directly connected to changes in the children’s gut bacteria. This suggests that inulin works by changing which bacteria live in the gut, and these bacteria then produce more of these helpful chemicals.

All three groups showed some clustering of metabolic changes over the 6 months, suggesting that all children’s bodies were changing. However, only the inulin group showed the specific increases in the brain-supporting chemicals that were being studied.

The study found that changes in gut bacteria composition were significantly associated with changes in the brain-supporting chemicals. This means that children whose gut bacteria changed the most also had the biggest increases in putrescine, spermine, and tyrosine. This connection suggests that the benefits of inulin come from how it feeds the good bacteria in the gut, which then produce these helpful chemicals.

Previous research has shown that the gut and brain are connected through what scientists call the ‘gut-brain axis.’ This study builds on that knowledge by showing that inulin specifically boosts certain chemicals that support this communication. Earlier studies suggested inulin might help with weight management, but this research provides a clearer picture of how it works at the chemical level. The findings align with other research showing that certain gut bacteria produce brain-supporting chemicals, but this is one of the first studies to show this effect clearly in children with obesity.

This study has several important limitations to keep in mind. First, 6 months is a relatively short time period—we don’t know if the benefits continue after stopping the supplement or if they last for years. Second, the study only measured chemicals in the blood; we can’t be sure these changes actually improved the children’s brain function or helped them lose weight long-term. Third, the study didn’t track whether children actually lost weight or felt better. Fourth, the sample size of 154 children is moderate; larger studies might show different results. Finally, we don’t know if these results would apply to children of different ages, ethnicities, or with different types of obesity.

The Bottom Line

Based on this research, inulin supplementation shows promise for children with obesity, but it’s too early to make strong recommendations. The evidence suggests inulin may help boost brain-supporting chemicals through gut bacteria changes (moderate confidence level). However, before giving inulin to children, parents should consult with their pediatrician or a registered dietitian. More research is needed to confirm whether these chemical changes actually lead to weight loss or improved health outcomes.

This research is most relevant to parents of children aged 7-15 with obesity who are looking for additional support beyond diet and exercise. It may also interest healthcare providers treating childhood obesity and researchers studying the gut-brain connection. This research is NOT a replacement for healthy eating, physical activity, or medical treatment. Children with certain medical conditions or those taking specific medications should check with their doctor before starting any supplement.

In this study, significant changes in brain-supporting chemicals appeared after 6 months. However, we don’t know if benefits would appear sooner or later in other children. It’s realistic to expect that if inulin helps, it would take several months to see effects. Don’t expect immediate weight loss or behavior changes—this is a slow, biological process.

Want to Apply This Research?

  • Track daily inulin intake (grams per day) and weekly energy levels, mood, and appetite satisfaction on a 1-10 scale. This helps correlate supplement use with how the child feels over time.
  • Start with a small daily dose of inulin (2-3 grams) mixed into foods like yogurt or smoothies, gradually increasing to the study dose (8 grams daily) over 2-3 weeks to allow the gut to adjust. Log each dose and any digestive changes in the app.
  • Create a 6-month tracking plan that includes: weekly appetite and energy logs, monthly weight and waist measurements, and quarterly check-ins with a healthcare provider. Use the app to identify patterns between inulin use and how the child feels, while maintaining a food diary to ensure overall diet quality isn’t neglected.

This research is preliminary and should not replace medical advice from a healthcare provider. Inulin supplementation is not approved by the FDA as a treatment for obesity. Before giving any supplement to children, consult with a pediatrician or registered dietitian, especially if your child has digestive conditions, allergies, or takes medications. This study shows promise but does not prove that inulin will help your child lose weight or improve health. Individual results vary, and more research is needed. Do not use this information to diagnose or treat any medical condition.