Breast Milk's Hidden Heroes: How Friendly Bacteria Fight Off Dangerous Germs

Breast milk is more than just food for babies. It's a powerhouse of good bacteria that can help fight off nasty infections. Scientists have found that certain types of these friendly bacteria, called Limosilactobacillus fermentum, can boost the body's defenses against a harmful germ called Neisseria meningitidis. This germ can cause serious illnesses like meningitis. The researchers looked at 113 different types of bacteria from breast milk. They found two superstars, BM-18 and BM-103, which are tough and can survive in harsh conditions. These bacteria are like tiny superheroes. They stick to the cells lining our airways and don't cause any harm. Instead, they help fight off the bad guys. When these friendly bacteria meet the harmful Neisseria meningitidis, they don't back down. They stick to it and fight it off. But that's not all. They also help calm down the body's overreactive immune response. This means they can reduce inflammation caused by the infection. The researchers found out how these friendly bacteria do their job. They activate a specific pathway in our cells, called the TLR-2/p38-MAPK/NF-κB pathway. This pathway helps the body produce more of a natural antibiotic called hBD-2. This antibiotic helps fight off the infection. On the other hand, the harmful Neisseria meningitidis tries to trick the body by activating a different pathway, TLR-4/MyD88/A20, which suppresses hBD-2. But the friendly bacteria outsmart it by activating their own pathway. This discovery is exciting because it shows that breast milk contains bacteria that can help fight off infections. However, more research is needed to see if these bacteria can be used as probiotics to prevent or treat infections in humans.