Question

Which of the following is NOT a benefit provided by the normal microbiota of the gastrointestinal (GI) tract?

a. Some members of the microbiota synthesize vitamins.
b. Some members of the microbiota fix nitrogen and provide a significant source of amino acids.
c. They assist with the enzymatic breakdown of some nutrients, particularly polysaccharides.
d. As a result of microbial antagonism, some members of the normal microbiota prevent pathogens from establishing a gastrointestinal infection.

Answer 1

The normal microbiota of the gastrointestinal (GI) tract provides several benefits including vitamin synthesis, nitrogen fixation, enzymatic breakdown of nutrients, and protection against pathogens.

Step-by-step explanation:

The normal microbiota of the gastrointestinal (GI) tract provides several benefits to the body. These include:

1. Some members of the microbiota synthesize vitamins. Bacteria like lactic acid bacteria can produce vitamins such as vitamin B12, folate, and riboflavin that humans cannot synthesize.
2. Some members of the microbiota fix nitrogen and provide a significant source of amino acids. Certain bacteria in the GI tract can fix atmospheric nitrogen and convert it into a form that can be used by the body.
3. They assist with the enzymatic breakdown of some nutrients, particularly polysaccharides. The microbiota helps in the digestion of complex carbohydrates and fiber that humans cannot digest on their own.
4. As a result of microbial antagonism, some members of the normal microbiota prevent pathogens from establishing a gastrointestinal infection. The presence of beneficial bacteria in the GI tract can inhibit the growth of harmful pathogens, thereby protecting against infection.

Therefore, the correct answer is d. As a result of microbial antagonism, some members of the normal microbiota prevent pathogens from establishing a gastrointestinal infection.