The largest diphtheria outbreak to strike Western Europe in 70 years has been affecting vulnerable people such as migrants and the homeless since 2022, new research said Wednesday. A baby's makeup of ...

Gram-positive bacteria have thick cell walls. A Gram stain test, which involves a chemical dye, stains the bacterium’s cell wall purple. On the other hand, gram-negative bacteria stain pink instead.

In recent years, scientists have learned that the key beneficial infant gut bacteria Bifidobacterium infantis are disappearing from infants in high-resource areas such as the United States and Europe.