How to know if probiotics have gone bad?

According to a study of 33 expired probiotic products, most had viable cell counts significantly below the recommended effective dose, highlighting the importance of knowing when your probiotics are no longer potent. Because probiotics contain live organisms, their effectiveness depends entirely on their viability, which can decline over time or with improper storage.

Quick Summary

Probiotics can lose their potency or spoil due to age, storage errors, or contamination. Check the expiration date, look for unusual smells, visible mold, or changes in color and texture. Decreased effectiveness may also signal a loss of viability.

Key Points

• Expiration Date is Key: Always check the 'best by' or expiration date, as potency is not guaranteed after it passes.

• Check for Clumping: In supplements, clumps or hardened powder signal moisture contamination and a likely loss of viability.

• Inspect for Mold: Any sign of mold on supplements or fermented foods, regardless of color, means it should be discarded.

• Use the Smell Test: An off-putting, foul, or rancid smell is a strong indicator of spoilage in both supplements and fermented foods.

• Monitor Texture Changes: Curdled yogurt or slimy fermented vegetables suggest spoilage and are unsafe for consumption.

• Store Properly: Follow label instructions, keeping probiotics away from heat, humidity, and direct sunlight to maximize their shelf life.

The effectiveness of probiotics hinges on the survival of live microorganisms, and several factors can compromise their potency or cause them to go bad. The signs of spoilage differ depending on whether you're consuming supplements or fermented foods, but they generally involve changes in smell, texture, and appearance. While expired probiotics are not always dangerous to consume, their therapeutic benefits are likely diminished.

Spotting Spoilage in Probiotic Supplements

Probiotic supplements, including capsules and powders, are formulated to be more stable than live foods, but they are still susceptible to environmental factors like heat and moisture.

• Expiration Date: The first and most reliable indicator is the 'best by' or expiration date on the package. This date is the manufacturer's guarantee that the product contains the labeled amount of live, effective microorganisms when stored correctly. Beyond this date, the CFU (colony-forming unit) count will likely decline.
• Unusual Odor: If you open the bottle and notice an unpleasant or sour smell that was not there before, it could be a sign of degradation. A fresh probiotic supplement should generally have a neutral or slightly yeasty scent.
• Changes in Appearance or Texture: Be on the lookout for visible signs of moisture or contamination. This includes:
  • Clumping: Powder that is stuck together in a solid mass indicates moisture exposure.
  • Discoloration: Any visible change in the color of the powder or capsules.
  • Visible Mold: Mold is a clear sign that the product is compromised and must be discarded.

Recognizing Spoilage in Fermented Foods

For probiotic-rich foods like yogurt, kefir, sauerkraut, and kimchi, spoilage is often more evident through sensory clues.

• Yogurt and Kefir: These cultured dairy products can spoil if not properly refrigerated. Signs include:
  • Excessive Liquid: A small amount of liquid (whey) is normal, but a significant separation or pool of liquid can signal spoilage.
  • Mold: Any sign of mold, regardless of color, means it's time to throw it out.
  • Curdled or Lumpy Texture: The product should be smooth and creamy; a curdled or lumpy consistency is a warning sign.
  • Rancid Smell or Taste: A sour, rancid, or unusually bitter taste or smell indicates that the food has turned.
• Sauerkraut and Kimchi: These fermented vegetables rely on a salty brine to prevent harmful bacteria growth. Watch for:
  • Mold Growth: Mold on the surface, which can appear as white, green, blue, or pink fuzz.
  • Foul Odor: While they have a strong, characteristic smell, a rotten or foul odor is a sign of spoilage.
  • Texture Alterations: The vegetables should maintain some firmness; a mushy or slimy texture is a red flag.

The Role of Proper Storage

Proper storage is critical for maintaining probiotic viability and preventing spoilage. Heat, moisture, and light are the primary culprits that kill live cultures. Always follow the manufacturer's instructions, but here are some general guidelines:

1. Check the label: Determine if your product is shelf-stable or requires refrigeration.
2. Avoid heat: Do not store probiotics in warm, humid places like a bathroom cabinet or a hot car.
3. Keep it dry: Ensure the cap is tightly sealed after each use to protect from moisture.
4. Protect from light: Store in opaque containers away from direct sunlight.

Comparing Good vs. Bad Probiotics

Characteristic	Good Probiotics (Supplements)	Bad Probiotics (Supplements)	Good Probiotics (Yogurt/Kefir)	Bad Probiotics (Yogurt/Kefir)
Expiration Date	Within date	Passed date	Within date	Passed date
Appearance	Uniform color, dry powder/capsule	Clumped, discolored, moldy	Smooth, creamy, minimal whey	Moldy, curdled, excessive liquid
Smell	Neutral or mild/yeasty	Sour, off-putting, rancid	Tangy, slightly sour (normal)	Pungent, foul, musty
Texture	Fine, free-flowing powder	Hardened or clumpy	Smooth, creamy consistency	Lumpy, grainy, or watery
Efficacy	Provides intended digestive benefits	Benefits may be significantly reduced	Maintains digestive support	Decreased or no benefit; possible GI distress

Conclusion

Knowing how to spot the signs of spoiled probiotics is essential for maximizing their health benefits and ensuring your safety. For supplements, rely on the expiration date and watch for physical changes like clumping or discoloration caused by improper storage. For fermented foods, trust your senses: any signs of mold, excessive liquid, or a foul odor mean it's time to discard the product. Always prioritize proper storage by keeping probiotics in a cool, dry place, and consult the label for refrigeration requirements. When in doubt, it is always safer to throw out any product you suspect has gone bad rather than risk consuming a less effective or potentially harmful one.

Medical News Today offers additional advice on checking the safety of expired vitamins and supplements.

Frequently Asked Questions

Are expired probiotics dangerous to take?

While generally considered safe and not likely to cause harm, expired probiotics lose their potency over time. The number of viable bacteria decreases, making them less effective and potentially offering no health benefit.

Can improper storage cause probiotics to go bad before the expiration date?

Yes, improper storage is a major cause of premature spoilage. Exposure to heat, moisture, or light can kill the live cultures, rendering the product ineffective and potentially encouraging the growth of unwanted organisms.

What if my probiotic yogurt has a lot of liquid on top?

Some liquid separation, called whey, is normal. However, an excessive amount of liquid can indicate spoilage, especially if paired with a curdled texture or a foul smell.

How can I tell if my sauerkraut has spoiled?

Spoiled sauerkraut will have a foul or rotten smell, show signs of mold growth (fuzzy spots of various colors), or develop a slimy texture. A normal, pungent aroma is expected, but a rotten smell is a clear warning.

Should I throw away clumpy probiotic powder?

Yes, clumpy probiotic powder should be discarded. The clumping is caused by moisture getting into the container, which can activate and kill the dormant bacteria, reducing the product's effectiveness.

How do I know if my refrigerated probiotics are still good if I left them out?

If your refrigerated probiotics were left out for an extended period, they may lose their viability due to heat exposure. Check for any changes in smell, color, or texture. When in doubt, it is best to replace them for optimal results.

Do shelf-stable probiotics last longer than refrigerated ones?

Shelf-stable probiotics are formulated with more resilient strains or with special packaging to withstand room temperature. When stored correctly, they can last for a long time, but their longevity ultimately depends on the manufacturing process and the specific strains used.