Final answer:
Biotin is the B vitamin synthesized by bacteria in the intestine besides being found in egg yolk and peanuts.
Step-by-step explanation:
Besides food sources like egg yolk and peanuts, bacteria in the intestine make the B vitamin Biotin. Many bacteria in the digestive system are part of the gut flora which contribute to the synthesis of certain essential vitamins. Among the options provided, biotin is the correct answer as it is synthesized by intestinal bacteria. Vitamins like Folate (B9), Pantothenic acid (B5), and Vitamin B12 (Cobalamin) are also available in various food sources, but according to the specific detail in the question, biotin is notably produced by gut bacteria, fulfilling part of the body's requirement for this vitamin. Hence, in addition to dietary sources such as eggs, liver, fish, meat, beans, and germinating seeds, biotin can also be synthesized by intestinal flora.