Question

Which vitamin is synthesised by the bacteria in human gut?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin K

Answer 1

The correct option is D Vitamin K

Escherichia coli are Gram-negative, facultative aerobic bacteria. They are common inhabitant of human gut. These strains of E. coli are harmless. They form the part of the normal microbiota of the intestine. They live in symbiotic association. They benefit hosts by producing vitamin K${}_2$ and preventing colonization of the intestine with pathogenic bacteria.

Thus, the correct answer is 'Vitamin K.'