Question

Which of the following substances produced from lactose stimulates the growth of bifidobacterium in the intestine of bottle fed infants

• A. Lactitol
• B. Lactulose
• C. Lactate
• D. Saccharic acid

Hint:

Lactulose is a classic prebiotic disaccharide produced by the isomerization of lactose during heating. It is widely used in infant formulas to promote a healthy gut microbiota dominated by bifidobacteria.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Human milk contains oligosaccharides that act as prebiotics (bifidus factors), promoting the growth of beneficial Bifidobacterium species in the gut of breastfed infants.
Bottle-fed infants consuming bovine milk formulas lack these oligosaccharides, which can lead to a less favorable gut microbiota.

Step 2: Detailed Explanation:
Let us evaluate the options to identify the substance that acts as a prebiotic:
- Lactulose is a synthetic disaccharide consisting of D-galactose and D-fructose linked by a \(\beta\)-(1,4) glycosidic bond.
- It is formed in small quantities from lactose through isomerization during the heat processing (pasteurization or sterilization) of milk.
- Lactulose is not digested or absorbed in the human small intestine because the body lacks the specific enzyme to break it down.
- It passes intact into the colon, where it is fermented by beneficial probiotic bacteria, primarily Bifidobacterium and Lactobacillus species.
- It acts as a prebiotic (bifidus factor), stimulating the growth of these beneficial bacteria and helping establish a protective, acidic environment in the infant gut.
- Other options like Lactitol (a sugar alcohol), Lactate (salt of lactic acid), and Saccharic acid do not function as the primary bifidus factor in this context.
Therefore, lactulose is the correct substance.

Step 3: Final Answer:
The substance produced from lactose that stimulates the growth of bifidobacterium is lactulose.