Question

Which statement is not true in relation to probiotic strains?

• A. Health benefits of probiotics are strain specific
• B. Probiotic culture must remain viable and stable in the product during storage
• C. Probiotic products must be harmless to the consumers
• D. Yoghurt starter culture possess probiotic properties

Hint:

Standard yogurt bacteria (L. bulgaricus and S. thermophilus) are transient starters.
They help digest lactose in the cup but do not colonize the human gut, meaning they are not classified as probiotics.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host."
To be classified as a probiotic, a strain must meet strict functional and survival criteria.

Step 2: Detailed Explanation:
Let us evaluate each statement about probiotics:
- Statement (A): This is true. The health benefits of probiotics (such as cholesterol lowering or immune modulation) are highly strain-specific and cannot be generalized to an entire species.
- Statement (B): This is true. For a probiotic to be effective, a high number of viable cells (typically at least \( 10^6 \) to \( 10^7\text{ cfu/g} \)) must survive and remain stable in the food product until consumption.
- Statement (C): This is true. Probiotic strains must be completely safe, non-pathogenic, and harmless to the host.
- Statement (D): This is not true. Standard yogurt starter cultures (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) are transient, cannot survive gastric acid and bile in high numbers, and do not colonize the human gut.
Therefore, they do not possess probiotic properties in the strict scientific sense, unless the yogurt is specifically fortified with dedicated probiotic strains like Lactobacillus acidophilus or Bifidobacterium.
Thus, statement (D) is the incorrect statement.

Step 3: Final Answer:
The statement that is not true is option 4 (Yoghurt starter culture possess probiotic properties).