Lactobacilli are harmful bacteria.

The correct option is B False

Lactobacilli:

1. Also known as lactic acid bacteria, Lactobacillus acidophilus is a gram-positive bacterium.
2. This group of bacteria provides us with a lot of benefits which include improvement in digestion and immunity to curdling milk and many more.
3. This bacterium also protects us from infectious diseases like traveler's diarrhea and rotaviral diarrhea.

Final answer: The given statement is false.