By Dr. Melody Khorrami, PharmD, RPh, INHC

Probiotics are live microorganisms that are intended to have health benefits when they are consumed. They can be found in fermented foods, and yogurts, as well as certain dietary supplements. Some of these bacteria can help to digest food and produce vitamins. Knowing the different types of bacteria and fungi and their different characteristics is an important part of understanding the role of these microorganisms.

In this article, we delve into the world of probiotics and the different types of bacteria and fungi. From yeast-based products to spore-based, and lactic acid bacteria, we explore the unique benefits of each type and how they can improve your digestive health, play a role in the immune system, and overall well-being.

Yeast-based probiotics come from a group of microbes called fungi. Some fungal species live in our gut, so it makes sense that yeast-based probiotics could be helpful. The most abundant genera of fungi in the human gut according to the Human Microbiome Project are Saccharomyces, Candida, and Malassezia. One popular yeast-based probiotic is Saccharomyces boulardii, often used for short-term stomach problems, bacterial diarrhea, and even inflammatory bowel diseases. It may also play a role in conditions like H-Pylori and C-difficile.

Spore-based probiotics from the Bacillus species are also used as probiotics. These species are dormant and are typically in a desiccated state. It is believed that they are not natural colonizers of the human gut, meaning they don’t originate in the human gut, and they usually colonize after a person eats certain vegetables or raw ingredients. They are typically available in supplement form for mild gastrointestinal disorders like diarrhea, or for conditions like leaky gut, or gut permeability. They are also used in the agricultural space as a possible alternative to antibiotics. There is a theory that most probiotics do not survive the environment of the digestive system and a person could be getting dead bacteria. Spore-based probiotics, however, may be able to survive this environment and be viable and reach the small intestines alive. Bacillus strains also have higher stability in heat conditions. Spore-based probiotics are also very resilient and can even resist some antibiotics. A downfall of spore-based probiotics is that they can be opportunistic especially in immunocompromised people, potentially causing infections.

Lactic acid bacteria are one of the most common groups of probiotic bacteria and are often used in fermented dairy products. Some of the benefits of these bacteria include stimulating the immune system, and helping with symptoms of irritable bowel syndrome, ulcerative colitis, and diarrhea. They are commonly used in the fermented food industry.

Lactic acid bacteria are also responsible for synthesizing vitamins in the body. Common lactic acid bacteria include Lactobacillus and Bifidobacterium. One of the problems with these strains of bacteria is that they are very sensitive to heat and light. They are also transient in nature, meaning they do not permanently stay in the gut, and typically probiotics containing these bacteria need to be taken consistently to see a positive effect. Some of the benefits of Lactobacillus and Bifidobacterium include supporting inflammatory bowel disease, potential benefits in anxiety, allergic and inflammatory conditions, as well as bacterial overgrowth.

Each of the three types of probiotics can be beneficial and can help with certain health concerns. When choosing a probiotic, there are some key components to look for, including the species and colony forming units (CFU) listed, the manufacturer information and expiration date, certification for following good manufacturing practices (GMP), and verification of potency by a third-party analysis of the lab used. You should always talk to your healthcare provider regarding the risks and benefits of using each type of probiotic.