Researchers compared the gut bacteria of 10 boys with autism to 10 boys without autism, all around age 6. They found that children with autism have different types of bacteria living in their stomachs and also have more trouble with eating behaviors. The study also showed that kids with autism tend to eat differently and may not get enough of certain nutrients. These findings suggest that doctors should pay more attention to stomach health and eating habits when helping children with autism.

The Quick Take

  • What they studied: Do children with autism have different bacteria in their stomachs and different eating habits compared to children without autism?
  • Who participated: 20 boys around age 6 years old—10 with autism and 10 without autism. Parents answered questions about their children’s eating habits, stomach problems, and what they ate.
  • Key finding: Children with autism had different types of stomach bacteria and more difficulty with eating behaviors. Specifically, they had more of certain bacteria (like Clostridium and Ruminococcus) and less of others (like Blautia and Bifidobacterium) compared to children without autism.
  • What it means for you: This small study suggests that stomach bacteria differences may be connected to autism and eating challenges. However, because this is a very small pilot study, we need larger research before making any changes to how autism is treated. If your child has autism and stomach problems, talking to a doctor about gut health may be helpful.

The Research Details

This was a pilot study, which means it was a small test to see if a bigger study would be worth doing. Researchers collected poop samples from 10 boys with autism and 10 boys without autism (all around age 6). They used special lab techniques to identify all the different bacteria living in each child’s stomach. Parents filled out detailed questionnaires about their children’s eating habits, any stomach problems, and what they ate over two days. The researchers then compared the bacteria types between the two groups and looked at the eating behavior differences.

The study measured eating behaviors using a special tool called the BAMBI scale, which asks parents about mealtime challenges like refusing foods, eating too fast, or having trouble with textures. Researchers also looked at what nutrients the children were getting from their food, including things like sodium, vitamins, and minerals.

This type of study is called a ‘comparative pilot study’ because it compares two groups but uses a small number of participants to test the idea before doing a larger study.

Understanding the differences in gut bacteria between children with and without autism is important because the stomach bacteria affect digestion, nutrition, and even mood and behavior. If we can identify specific bacteria differences, doctors might eventually be able to help children with autism feel better by addressing their stomach health. This research also highlights that eating difficulties in autism might be connected to both behavior and biology, not just one or the other.

This is a very small pilot study with only 20 children total, so the results are preliminary and shouldn’t be considered definitive. The study only included boys, so we don’t know if the findings apply to girls with autism. The sample size is too small to make strong statistical claims. However, pilot studies are valuable for identifying patterns that deserve larger research. The use of genetic sequencing to identify bacteria is a reliable scientific method, and the study used established questionnaires to measure eating behaviors, which strengthens the quality of the data collected.

What the Results Show

The most important finding was that children with autism had significantly different gut bacteria compared to children without autism. In the control group (children without autism), a bacteria type called Bacteroidota was most common. In contrast, children with autism had more Firmicutes, Actinobacteriota, and Proteobacteria.

When researchers looked at specific bacteria types, they found that children without autism had more ‘good’ bacteria like Blautia and Bifidobacterium. Children with autism had more of bacteria called Clostridium sensu stricto 1, Ruminococcus_torques_group, and Lachnospiraceae_UCG004, along with a different type of Bifidobacterium called Bifidobacterium breve.

The second major finding was about eating behaviors. Children with autism scored higher on the BAMBI scale, which measures mealtime difficulties. This means they had more challenges with eating, such as being very picky about foods, having trouble with food textures, or eating too quickly. Parents also reported that children with autism had more stomach-related problems and were eating less sodium (salt) than recommended.

The study also found that children with autism had more health conditions alongside their autism (called comorbidities), which may be related to their different gut bacteria and eating challenges.

The research showed that the differences in gut bacteria were not just random—they followed a clear pattern. The overall diversity and balance of bacteria were different between the two groups, suggesting that autism may be associated with an imbalance in the gut ecosystem. The dietary analysis showed that children with autism may not be getting enough of certain nutrients, possibly because they eat a more limited variety of foods. The connection between eating behavior difficulties and gut bacteria differences suggests these two issues may be related to each other.

Previous research has suggested that children with autism often have stomach problems and eating difficulties more often than other children. This study adds to that knowledge by showing that the actual bacteria living in their stomachs are different. Some earlier studies have found similar bacteria differences in autism, but this is one of the first to directly compare both the bacteria and eating behaviors in the same group of children. The findings fit with the growing understanding that autism affects not just the brain but also the digestive system.

This study is very small with only 20 children, so the results might not apply to all children with autism. The study only included boys around age 6, so we don’t know if girls or older/younger children would show the same patterns. The study didn’t follow children over time, so we can’t tell if the bacteria differences cause the eating problems or if eating problems cause the bacteria differences. The study didn’t measure many other factors that could affect gut bacteria, like whether children took antibiotics, what they ate before the study, or other health conditions. Because this is a pilot study, larger research is needed to confirm these findings before doctors should change how they treat autism based on this information.

The Bottom Line

Based on this small pilot study, we cannot yet make strong recommendations for changing treatment. However, the findings suggest that doctors should consider paying attention to stomach health and eating habits in children with autism. If your child with autism has stomach problems or very limited eating habits, discussing gut health with your pediatrician may be worthwhile. Larger studies are needed before any new treatments based on these findings should be used. (Confidence level: Low, due to small sample size)

Parents of children with autism who also have eating difficulties or stomach problems should find this research interesting. Healthcare providers working with autistic children may want to monitor this research area. Children with autism who have very limited diets or frequent stomach issues might benefit from further evaluation. This research is less relevant for children without autism or those with autism who don’t have eating or digestive challenges.

This is a pilot study, so we should expect 2-5 years of larger research before any new treatments based on these findings might become available. If doctors do eventually recommend changes to help gut bacteria in children with autism, benefits would likely take several weeks to months to notice, similar to how long it takes for dietary changes to affect digestion in anyone.

Want to Apply This Research?

  • Track your child’s daily eating variety by recording how many different food groups they eat each day (fruits, vegetables, proteins, grains, dairy). Also note any stomach symptoms like bloating, constipation, or diarrhea to share patterns with your doctor.
  • If your child with autism has limited eating habits, try introducing one new food per week in a low-pressure way. Use the app to celebrate small wins, like trying a new food or eating a new color of vegetable. Track which foods cause stomach discomfort to identify patterns.
  • Over 3-6 months, monitor changes in eating variety, stomach symptoms, and mealtime behavior using the app. Take photos of meals to track dietary diversity. Share monthly summaries with your child’s healthcare provider to discuss whether any changes in diet or eating approach seem to help with both eating behaviors and stomach health.

This is a small pilot study with only 20 children and should not be used to diagnose or treat autism or digestive problems. The findings are preliminary and need confirmation through larger research studies. If your child has autism and experiences stomach problems, eating difficulties, or nutritional concerns, please consult with your pediatrician or a healthcare provider who specializes in autism. Do not make changes to your child’s diet or medical treatment based solely on this research without professional medical guidance. This information is for educational purposes only and is not a substitute for professional medical advice.