Carbonic acid has a pH of around 4 in sodas. Stomach acid is 3. Both are enough to discourage bacterial growth. It doesn't prevent _all_ bacteria, as I said. B

Carbonic acid has a pH of around 4 in sodas. Stomach acid is 3. Both are enough to discourage bacterial growth. It doesn't prevent _all_ bacteria, as I said. But it prevents most of pathogenic bacteria.