Researchers are planning a study to test whether two common artificial sweeteners—sucralose and saccharin—might affect blood sugar control and gut bacteria in people with type 2 diabetes. While these sweeteners are used to help manage diabetes, some new research suggests they might actually harm the body’s ability to control blood sugar by changing the bacteria in our digestive system. This study will have 33 people with type 2 diabetes try each sweetener for a week and measure how it affects their blood sugar levels and gut bacteria. The results could help doctors give better advice about which sweeteners are safe for people with diabetes.

The Quick Take

  • What they studied: Whether two artificial sweeteners (sucralose and saccharin) change how well the body controls blood sugar and affect the helpful bacteria living in the stomach and intestines.
  • Who participated: The study will include 33 adults who have type 2 diabetes. Participants will be randomly assigned to take either sucralose, saccharin, or a placebo (fake pill) for one week at a time.
  • Key finding: This is a study protocol (a plan for research), not yet completed research. The study hasn’t started enrolling participants as of December 2025, so there are no results yet. When finished, it will show whether these sweeteners actually affect blood sugar control and gut bacteria in people with diabetes.
  • What it means for you: If you have type 2 diabetes and use artificial sweeteners, this research may eventually help your doctor recommend which sweeteners are safest for you. However, we need to wait for the actual results before making any changes to what you eat or drink. This study is still in the planning stage.

The Research Details

This is a carefully designed experiment called a double-blind, randomized, placebo-controlled crossover trial. Here’s what that means in simple terms: Each participant will try three different things—sucralose, saccharin, and a placebo (a fake pill with no active ingredient)—but in random order. Neither the participants nor the researchers will know which pill contains which substance until the study is finished. This prevents bias from affecting the results.

Each person will take one type of pill for 7 days, then stop for 4 weeks to let their body return to normal (called a washout period), then try the next pill for 7 days. This crossover design is powerful because each person serves as their own comparison, which helps researchers see real effects more clearly.

The researchers will measure blood sugar control using blood tests and will analyze stool samples to see how the sweeteners affect the bacteria living in the gut. They’ll also track diet, exercise, and body measurements.

This research design is important because it’s one of the strongest ways to test whether a substance actually causes changes in the body. By having each person try all three options (and comparing them to placebo), researchers can be more confident that any changes they see are really caused by the sweeteners and not by other factors. The double-blind part ensures that expectations don’t influence the results.

This study has several strengths: it’s randomized (reducing bias), uses a placebo control (so researchers can see real effects), and is double-blind (preventing expectations from affecting results). The crossover design is also strong because each person serves as their own control. However, the sample size is relatively small (33 people), and the study only lasts 7 days per sweetener, so we’ll only learn about short-term effects. The study hasn’t started yet, so there’s no data to evaluate.

What the Results Show

This is a protocol paper, which means it describes the plan for a study that hasn’t been completed yet. As of December 2025, no participants have enrolled, and no results are available. The study is scheduled to begin recruiting participants in January 2026 and should be finished by March 2027.

When the study is complete, researchers will measure two main things: (1) how well each person’s body controls blood sugar after taking each sweetener, and (2) how the sweeteners change the types and amounts of bacteria in the gut. They’ll use blood tests to measure blood sugar control and genetic testing to identify which bacteria are present in stool samples.

The study will compare results from the sucralose weeks, saccharin weeks, and placebo weeks to see if either sweetener causes changes compared to the fake pill.

Researchers will also look at other measurements including body weight, insulin sensitivity (how well the body uses insulin), and dietary patterns. They’ll track physical activity levels to make sure exercise doesn’t explain any changes they see. These measurements help paint a complete picture of how the sweeteners might affect overall health.

Recent research has raised concerns that artificial sweeteners might harm blood sugar control, even though they were designed to help people with diabetes. Some studies suggest this might happen because sweeteners change the bacteria in the gut, which affects how the body processes sugar. However, most of this research has been done in animals or in test tubes, not in real people with diabetes. This study will be one of the first to carefully test this idea in actual patients with type 2 diabetes, making it an important addition to what we know.

This study only tests the short-term effects (7 days) of these sweeteners, so we won’t know what happens if people use them for months or years. The sample size is small (33 people), which means the results might not apply to all people with diabetes. The study is being done in Malaysia, so results might be different in other countries with different populations. Also, the study uses capsules with measured doses, which is different from how people actually consume sweeteners in food and drinks in real life.

The Bottom Line

Wait for the results of this study before making changes. If you currently use artificial sweeteners and have type 2 diabetes, continue your current habits unless your doctor advises otherwise. Once this research is completed (expected in 2027), discuss the findings with your healthcare provider to see if they apply to you. The confidence level for any recommendations is currently low because the study hasn’t been completed yet.

This research is most relevant for people with type 2 diabetes who use or are considering using artificial sweeteners. It’s also important for doctors and nutritionists who advise people with diabetes. People without diabetes might be interested but should know this study specifically focuses on people with type 2 diabetes. Pregnant women, children, and people with other health conditions should wait for additional research before applying these findings.

Since the study hasn’t started yet, we won’t have results until at least mid-2027. Even after results are published, it may take several months for doctors to review the findings and update their recommendations. Real changes in your diet or sweetener use should only happen after discussing results with your healthcare provider.

Want to Apply This Research?

  • Once this research is published, users with type 2 diabetes could track their blood sugar readings (fasting glucose and post-meal readings) for one week while noting which sweeteners they consumed, then compare patterns across different weeks. This personal tracking would help them see if they individually respond to these sweeteners.
  • Users could use the app to log which artificial sweeteners they consume daily and correlate this with their blood sugar readings. If the research shows concerning effects, users could gradually reduce one sweetener at a time and track whether their blood sugar control improves.
  • Set up weekly reminders to check fasting blood sugar levels and log sweetener consumption. Create a simple chart showing blood sugar trends alongside sweetener intake over 4-week periods. Share this data with a healthcare provider during regular check-ups to see if patterns emerge.

This article describes a research study that is still in the planning stage and has not yet produced results. No participants have been enrolled as of December 2025. This information is for educational purposes only and should not be used to make changes to your diet or diabetes management. If you have type 2 diabetes and use artificial sweeteners, continue your current habits and consult with your doctor or registered dietitian before making any changes. Do not stop taking any diabetes medications or change your diet without medical supervision. Always work with your healthcare provider to make decisions about your diabetes management.