The additives that make processed foods creamy, smooth, and long-lasting might come with a hidden cost. A recent study in mice found that common dietary emulsifiers disrupt glucose regulation and alter the gut microbiota, potentially contributing to metabolic disorders and immune dysfunction.

Researchers fed mice diets containing four commonly used emulsifiers: lecithin, sucrose esters, carboxymethylcellulose, and mono- and diglycerides. Then, they analyzed how the compounds affected the gut’s protective mucus barrier and microbial diversity.

They found that sucrose esters and carboxymethylcellulose elevated the animals' blood glucose and lipids, disrupted glucose regulation, and altered gut microbiota. Similarly, mono- and diglycerides impaired glucose and lipid metabolism, but they also raised markers of inflammation and increased bacterial encroachment into the gut mucus layer, potentially impairing immune function.

These findings suggest that dietary emulsifiers promote metabolic dysfunction by altering the gut microbiota and disrupting glucose and lipid regulation. Notably, the amounts of emulsifiers in the animals' diets represented a much higher proportion of dietary intake than what humans typically consume, as emulsifiers in processed foods are usually in smaller amounts. Still, long-term consumption could increase exposure through a diet high in processed foods containing emulsifiers.

Emulsifiers are common in processed foods, including ice cream, baked goods, margarine, salad dressings, and sauces. They help stabilize mixtures of oil and liquids, improving texture and shelf life. Their use reflects the broader role of food additives, which enhance flavor, preserve freshness, and improve processed food products' visual and textural appeal—often at the expense of health. Learn more about the harms of processed foods in Aliquot #111: Why ultra-processed foods and their additives are harmful.