Artificial sweeteners might mess up the good bacteria in your gut, which could mean your body makes less of a helpful substance that keeps your blood sugar in check.

What you eat overall—like veggies, meat, or carbs—is probably what’s really changing your gut bacteria, not the sugar-free sweeteners in your diet.

Studies with people who drink diet sodas or eat foods with artificial sweeteners don’t show that these sweeteners change the good bacteria in your gut or how your body handles sugar, as long as you’re eating or drinking them in normal amounts.

Some sugar-free sweeteners like saccharin might mess up your gut bacteria and make your intestines leakier, which could lead to problems like higher blood sugar and trouble with insulin.