A “safe” food additive may be very dangerous for some people. The finding solves a medical mystery—why are so many people suddenly getting seriously ill from Clostridium difficile (C. diff) infections? The intestinal bacteria can cause severe, intractable bouts of diarrhea and lead to dangerous—even fatal—colon inflammation. It often is resistant to antibiotics. About a half million people get sick from this infection every year in the US—and 15,000 die. But serious C. diff infections were much rarer before the year 2000. Why the upsurge?
A POPULAR NEW ADDITIVE
Trehalose is a sugar that is found naturally in minuscule amounts in certain foods such as honey. But since a commercially produced version was approved as a food additive by the FDA—in the year 2000—larger amounts have flowed into our foods. It enhances flavor, reduces bitterness and adds sweetness to foods as varied as ice cream, baked goods, pastas and candies.
But trehalose also nourishes C. diff. A 2018 study published in Nature found that the two most virulent and deadly strains of C. diff metabolize trehalose and grow better than on other sugars. When researchers gave trehalose to mice infected with C. diff, the fatality rate of those mice tripled.
For people who acquire a C. diff infection—common in hospitals and other health-care settings—this means that having trehalose in your diet might give these especially dangerous, antibiotic-resistant strains an extra source of food. So they multiply.
WHEN TO AVOID TREHALOSE
For most people most of the time, there’s no need to avoid foods containing trehalose. Under normal circumstances, helpful bacteria in your gut outcompete C. diff, preventing illness.
But a great danger exists when you have a serious infection treated with “broad-spectrum” antibiotics, especially the kind that is serious enough to land you in the hospital. Those antibiotics wipe out helpful gut bacteria. Take action: Read ingredients lists on all packaged foods you eat, and avoid any that include trehalose while you are taking such antibiotics and for several weeks afterward. And avoid trehalose if you have or have recently recovered from a C. diff infection.