UPSC Prelims 2022 Q38: Science & Technology – Health & Diseases
Consider the following statements in respect of probiotics:
1. Probiotics are made of both bacteria and yeast.
2. The organisms in probiotics are found in foods we ingest but they do not naturally occur in our
gut.
3. Probiotics help in the digestion of milk sugars.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 2 only
- (c) 1 and 3
- (d) 2 and 3
Answer: (c) 1 and 3
Explanation
Probiotics — 'good' live microbes
| Statement | Verdict | Reason |
|---|---|---|
| 1. Made of bacteria and yeast | Correct | Bacteria like Lactobacillus and Bifidobacterium; yeast like Saccharomyces boulardii |
| 2. Found in foods but not naturally in our gut | Wrong | These microbes are naturally present in the human gut as part of the gut microbiome |
| 3. Help digest milk sugars | Correct | Lactobacilli make lactase, which breaks down lactose — helpful in lactose intolerance |
Probiotics vs prebiotics:
| Term | Meaning | Example |
|---|---|---|
| Probiotic | Live beneficial microbes | Curd, yoghurt, kefir |
| Prebiotic | Food (fibre) for good microbes | Banana, onion, garlic, oats |
Answer: (c) 1 and 3.
Why each option is right or wrong
- (a) Incorrect. It leaves out Statement 3; probiotic bacteria help digest lactose.
- (b) Incorrect. Statement 2 is false; probiotic microbes naturally live in the gut.
- (c) CORRECT. Probiotics include bacteria and yeast and help digest milk sugar (lactose).
- (d) Incorrect. Statement 2 is false; the gut naturally hosts these microbes.
Key point
Probiotics = live beneficial bacteria and yeasts (Lactobacillus, Saccharomyces); natural gut residents; aid lactose digestion.
Remember
Probiotics include bacteria and yeast and help digest milk sugar.
Common mistakes
- Thinking probiotics are only bacteria; yeasts are also used.
- Believing probiotic microbes are foreign to the gut; they are part of the natural microbiome.
- Confusing probiotics (live microbes) with prebiotics (fibre that feeds them).
Exam tip
Pro = life (microbes); Pre = food for them. Curd is the everyday probiotic.
Sources
- ICMR–DBT — Guidelines for Evaluation of Probiotics in Food (2011)
- NCERT Class XII — Biology, Ch 8 (Microbes in Household Products)