MIT scientists have discovered an intestinal protein called intelectin-2 that plays a dual role in defending the gut. This little-known protein strengthens the mucus layer that lines the gastrointestinal tract. At the same time, it captures and disables harmful bacteria that try to penetrate through this layer. Intelectin-2 binds to sugars on both mucus molecules and bacterial surfaces. It creates a protective barrier against microbes. The protein can even kill some bacteria, including those that are resistant to antibiotics.