Research shows that eating an oat-rich low-gluten diet increases butyrate, a beneficial gut chemical, more effectively than a rice-rich low-gluten diet. In a 2026 randomized trial of 69 people with heart disease risk factors, the oat group had significantly higher butyrate levels after six weeks (p=0.033). However, neither diet reduced inflammation markers, suggesting that while oats offer modest gut benefits, they don’t dramatically transform heart health markers in the short term.
A new study tested whether eating oats instead of rice on a low-gluten diet could help people with heart disease risk factors. Sixty-nine people followed either an oat-based or rice-based low-gluten diet for six weeks. According to Gram Research analysis, the oat group had higher levels of butyrate, a beneficial substance made by gut bacteria that supports heart health. However, the study found no major changes in gut bacteria diversity or inflammation markers in either group, suggesting that while oats may offer some benefits, the effects are more limited than previously hoped.
Key Statistics
A 2026 randomized controlled trial of 69 people with cardiometabolic risk found that an oat-rich low-gluten diet increased fasting plasma butyrate more than a rice-rich low-gluten diet (p=0.033), according to research published in The Journal of Nutrition.
In a six-week study of 69 adults, the rice-based low-gluten diet group showed greater changes in gut bacteria diversity (measured by Shannon diversity index) than the oat-based group (p=0.025), suggesting that switching to rice caused more disruption to the microbiome.
Despite increasing butyrate levels, neither the oat-rich nor rice-rich low-gluten diet produced significant changes in inflammatory markers across 45 measured cytokines in a 2026 trial of 69 people with cardiometabolic risk.
A 2026 study of 69 participants found that baseline oat consumption was already high in both groups, meaning the oat-rich diet represented less dietary change than the rice-rich diet, which may explain why the rice group experienced greater microbiome shifts.
The Quick Take
- What they studied: Whether eating an oat-rich low-gluten diet would improve gut health and reduce inflammation better than a rice-rich low-gluten diet in people at risk for heart disease.
- Who participated: 69 adults with increased cardiometabolic risk (meaning they have factors that increase heart disease chances) were randomly assigned to eat either oat-based or rice-based low-gluten foods for six weeks.
- Key finding: The oat group had significantly higher levels of butyrate (a healthy gut chemical) compared to the rice group. Butyrate increased by a greater amount in the oat group than the rice group (p=0.033, meaning this difference was statistically significant).
- What it means for you: If you’re following a low-gluten diet and want to support your heart health, choosing oat-based products over rice-based ones may help your gut produce more butyrate. However, this study suggests the benefits are modest, and you shouldn’t expect major changes in inflammation or gut bacteria diversity from this switch alone.
The Research Details
This was a randomized controlled trial, which is one of the strongest types of nutrition studies. Researchers divided 69 people into two groups: one ate oat-based low-gluten foods, and the other ate rice-based low-gluten foods. Both groups followed their assigned diet for exactly six weeks. The researchers collected blood samples, stool samples, and detailed food records at the beginning and end of the study.
To measure gut bacteria, scientists used advanced DNA sequencing technology (shotgun metagenomics) to identify which bacteria were present and in what amounts. They measured butyrate and other short-chain fatty acids using a specialized lab technique called UHPLC-MS. They also tested 45 different inflammation markers in the blood using a technology called Olink Target, which is very precise.
The researchers used statistical methods called linear mixed-effects models to compare how each group changed over the six weeks, accounting for individual differences between participants.
This research approach is important because it combines multiple measurements to give a complete picture. By measuring gut bacteria, blood chemicals, and inflammation markers together, researchers can see whether changes in one area (like butyrate) actually translate to improvements in others (like reduced inflammation). This helps us understand whether a dietary change is truly beneficial or just creates minor chemical shifts that don’t affect health.
This study has several strengths: it’s a randomized controlled trial (the gold standard for nutrition research), it used advanced laboratory techniques to measure outcomes precisely, and it was registered in a clinical trials database before starting. However, the study is relatively short (only six weeks), involves a small number of participants (69 people), and both groups were already eating low-gluten diets at baseline, which may have limited how much change researchers could observe. The study was published in The Journal of Nutrition, a reputable peer-reviewed journal.
What the Results Show
The main finding was that people eating the oat-rich low-gluten diet had higher levels of butyrate in their blood compared to those eating the rice-rich diet. Butyrate is a short-chain fatty acid produced when gut bacteria break down fiber, and it’s considered beneficial for heart and digestive health. The difference was statistically significant, meaning it’s unlikely to have happened by chance.
Interestingly, the rice group showed more changes in their gut bacteria diversity (measured by something called the Shannon diversity index) than the oat group. This suggests that switching from a habitual diet to a rice-based low-gluten diet caused more disruption to the gut bacteria community than switching to an oat-based diet. This may be because the participants were already eating oats regularly at the start of the study, so the oat diet was less of a change for them.
Despite these differences in butyrate levels and gut bacteria changes, the study found no significant differences between the groups in inflammatory markers. This means that neither diet produced measurable reductions in the 45 different inflammation-related substances measured in the blood. This was somewhat surprising, as researchers had hoped that improving the low-gluten diet with oats might reduce inflammation in people at heart disease risk.
The dietary analysis revealed that both groups were already consuming high amounts of oats at baseline, which explains why the oat-rich diet didn’t represent as dramatic a change as the rice-rich diet. The rice group experienced more substantial dietary changes, which may explain why their gut bacteria shifted more noticeably. However, these shifts in gut bacteria diversity didn’t translate to measurable health improvements in either group during the six-week study period.
Previous research has suggested that increasing fiber intake through whole grains like oats can improve gut health and reduce inflammation. This study partially supports that idea by showing that oats do increase butyrate production. However, it challenges the assumption that increased butyrate automatically leads to reduced inflammation markers. This suggests that the relationship between gut health and inflammation is more complex than previously thought, and that short-term dietary changes may not be enough to produce measurable improvements in inflammation.
The study lasted only six weeks, which may be too short to see major changes in inflammation or long-term health outcomes. The sample size of 69 people is relatively small, which limits how broadly we can apply the findings. Both groups were already eating low-gluten diets, and the oat group was already eating oats regularly, so the dietary changes weren’t as dramatic as they might be for people switching from a standard diet. The study didn’t measure long-term outcomes, so we don’t know if the increased butyrate from oats would eventually lead to health improvements over months or years. Additionally, the study focused on people with cardiometabolic risk, so results may not apply to people without these risk factors.
The Bottom Line
If you’re following a low-gluten diet and want to support your gut health, choosing oat-based products over rice-based products appears to be a reasonable choice, as oats increase butyrate production (moderate confidence). However, don’t expect this change alone to significantly reduce inflammation or dramatically transform your gut bacteria (low to moderate confidence). This dietary adjustment should be part of a broader approach to heart health that includes exercise, stress management, and overall dietary quality. If you have cardiometabolic risk factors, discuss any major dietary changes with your healthcare provider.
This research is most relevant to people who are already following a low-gluten diet and want to optimize it for heart health. It’s particularly relevant for people with cardiometabolic risk factors (such as high blood pressure, high cholesterol, or excess weight). People without these risk factors or those not following a low-gluten diet may not see the same benefits. This research is less relevant for people with celiac disease, who must avoid gluten for medical reasons rather than choice.
Based on this study, you might expect to see changes in butyrate levels within six weeks of switching to an oat-rich low-gluten diet. However, you shouldn’t expect to see major reductions in inflammation markers or dramatic shifts in gut bacteria within this timeframe. Longer-term studies would be needed to determine if these butyrate increases lead to health improvements over months or years.
Frequently Asked Questions
Does eating oats on a low-gluten diet reduce inflammation?
A 2026 study of 69 people found that an oat-rich low-gluten diet increased butyrate but did not significantly reduce inflammation markers. While oats may support gut health through butyrate production, this study suggests they don’t produce measurable inflammation reduction in six weeks.
What’s the difference between butyrate from oats and rice in a low-gluten diet?
The oat-rich diet increased butyrate significantly more than the rice-rich diet (p=0.033). Butyrate is a short-chain fatty acid produced by gut bacteria that supports digestive and heart health. Oats’ higher fiber content appears to promote more butyrate production than rice.
How long does it take to see health benefits from switching to oats on a low-gluten diet?
This study measured changes over six weeks and found increased butyrate but no inflammation reduction. Longer studies would be needed to determine if butyrate increases eventually improve health outcomes. Individual results may vary, so tracking your own response over 6-8 weeks is recommended.
Will changing my gut bacteria help my heart health if I’m on a low-gluten diet?
This study found that an oat-rich low-gluten diet increased butyrate and caused less microbiome disruption than a rice-rich diet, but neither diet reduced inflammation markers. While gut bacteria changes are important, this study suggests they may not immediately improve measurable heart health markers.
Is a low-gluten diet with oats better than with rice for people with cardiometabolic risk?
For people already eating oats regularly, an oat-rich low-gluten diet produced more butyrate than a rice-rich diet. However, neither diet significantly reduced inflammation in six weeks. The choice between oats and rice should be part of a broader heart-healthy approach including exercise and overall diet quality.
Want to Apply This Research?
- Track your daily oat consumption (in grams) and note any changes in digestive comfort, energy levels, or bloating over a 6-8 week period. Record whether you’re eating oat-based products versus rice-based products, and monitor any subjective improvements in how you feel.
- If you’re using a nutrition app and following a low-gluten diet, swap rice-based products for oat-based alternatives in at least one meal per day. Start with oatmeal for breakfast, oat flour in baking, or oat-based snacks. Track this substitution and note any changes in your digestive health or energy levels.
- Over 6-12 weeks, maintain a food log specifically tracking oat consumption versus rice consumption. Pair this with periodic notes on digestive health, energy levels, and any inflammation-related symptoms (like joint pain or fatigue). While this study didn’t show inflammation changes, individual responses vary, so personal tracking may reveal patterns specific to you.
This research is informational and should not replace professional medical advice. The study involved people with cardiometabolic risk factors and lasted only six weeks, so results may not apply to all populations or predict long-term outcomes. Before making significant dietary changes, especially if you have heart disease risk factors, diabetes, or other health conditions, consult with your healthcare provider or a registered dietitian. This study shows that oats increase butyrate but did not demonstrate reduced inflammation, so don’t expect this dietary change alone to treat or prevent disease.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.