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Probiotic Myths, Pros and Cons

Probiotic Quality Myths

For a probiotic to work, first it has to survive storage in the bottle with enough potency remaining to be of benefit by the time you take it. The probiotic also has to survive the harsh acidic environment of your stomach and make it into your intestines alive. If the product requires refrigeration, then it’s probably too fragile to survive long on the shelf or inside your stomach.

And to be a true probiotic, the species need to be a natural part of the environment and a normal part of your digestive system. Unfortunately, more than 90% of probiotics sold today don’t meet these requirements of a true probiotic1.

Probiotic Product Pros and Cons

Many popular probiotics are made with species of bacteria belonging to the Lactobacillus or Bifidobacteria groups. Both of these groups make up the largest population of organisms living inside your gut. The trouble is, these bacteria are fragile and easily killed by stomach acid before they reach the intestines where they are needed. And because they are already present in the gut in large amounts, some research suggests that supplementation with these two species has little or no effect on the overall balance of bacteria inside the gut.

S. boulardii, a helpful yeast probiotic

The beneficial yeast species Saccharomyces boulardii (S. boulardii or Sac b.) is a form of bakers yeast and it has some unique benefits for C. difficile infections, including diarrhea support. Since Sac b. is a hardy yeast and not a bacteria, it is naturally resistant to antibiotic drugs as antibiotics only kill bacteria. Therefore, you don’t need to be concerned about taking Sac b. alongside oral antibiotics like you do with most other probiotics.

There are several probiotics on the market containing S. boulardii either by itself or as part of a multi-strain formula. Many holistic doctors prefer a more complete, broad spectrum probiotic formulation that includes S. boulardii, or combining it with another broad-spectrum probiotic formula. Sac b. may be especially helpful during the active diarrhea stage of C. difficile infections.

If you have a catheter or IV, be sure to take extra safety precautions with your doctor. There appear to be several instances of Sac b. causing a blood infection through central venous catheters, likely caused by contaminated hospital staff hands 2. S. boulardii is not a good choice if you are allergic to yeast. Be sure to discuss the use of this probiotic with your doctor, especially if you are immune-compromised or critically ill.

The Benefits of Soil Based Organisms (SBO’s)

Soil based organisms or SBO's

SBO’s are natural organisms found in the soil.

Recent scientific studies are giving Soil Based Organisms (SBO’s) a lot of attention lately. SBO’s include many different microorganisms, but not all are suitable for probiotic uses. Not all SBO’s colonize the gut or survive passage through the stomach. And not all SBO’s form spores, which are beneficial for probiotic uses. Likewise, not all spore-based organisms are SBO’s.

Bacillus species are hardy spore-forming probiotics that can survive the stomach and populate the gut, thus they are the best SBO probiotic species. Bacillus species from the soil are naturally found on fruits and vegetables grown in the garden. People have incidentally eaten Bacillus bacteria throughout history and they are a natural resident inside the human gut.

Several strains of Bacillus have been shown to boost the immune system and ward off disease-causing bacteria and yeast inside the gut. And because Bacillus bacteria form spores, which are hard protective shells, they can survive 100% intact in the bottle and as they pass through your digestive system3. These spores also make Bacillus species highly resistant to light, heat and oxygen, making them very stable during shipping and storage. All these benefits make Bacillus ideal for use in high potency probiotic products.

While a growing number of holistic doctors love SBO probiotics and claim they are their best performing probiotics, SBO’s are not without controversy. Because Bacillus species are so hardy and retain their potency so well, some experts view them as an overly aggressive therapy. A conservative way to use SBO’s would be short-term use during an acute infection only. Tapering up slowly to the full usage amount and then tapering off again after the infection has passed can help reduce potential gut discomfort while taking SBO probiotics.

Like any probiotic, if you are severely immunocompromised or critically ill, probiotics may not be advised. Be sure to consult with your doctor before starting any new probiotic.

Find out how to choose a good probiotic supplement and learn other ways to benefit from probiotics.



  1. Guidelines for the Evaluation of Probiotics in Food http://www.who.int/foodsafety/fs_management/en/probiotic_guidelines.pdf
  2. Catheter-related Saccharomyces cerevisiae Fungemia Following Saccharomyces boulardii Probiotic Treatment: In a child in intensive care unit and review of the literature. Serkan Atıcı Ahmet Soysal. Med mycol Case Rep. 2017 Mar; 15: 33–35. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5333505/
  3. Commissioned gastric model study by Silliker Food Science Center – Crete, IL

Image credits: Bacteria combo graphic ©CDC and ©Les Moore, Human tree ©freshidea/Fotolia, Supplement bottles ©Elenathewise/Fotolia, children © Arlotta Martin/PHIL.