Bacillus subtilis is a spore-forming bacterium that is commonly used as a probiotic due to its ability to survive in harsh environments, such as the stomach, and produce enzymes that aid in digestion. Bacillus subtilis has also been shown to have antimicrobial properties, which can help reduce the growth of harmful bacteria in the gut.

Bacillus coagulans is another species of Bacillus that is commonly used as a probiotic. It has been shown to improve gut health, reduce inflammation, and enhance immune function. Bacillus coagulans has also been studied for its potential to improve digestion and reduce symptoms of irritable bowel syndrome (IBS).

Bacillus clausii is a spore-forming bacterium that is commonly used as a probiotic in Europe and Asia. It has been shown to improve gut health and reduce the risk of gastrointestinal infections. Bacillus clausii has also been studied for its potential to enhance immune function and reduce inflammation.

Bacillus mesentericus is a species of Bacillus that is commonly found in soil and plant matter. It is a spore-forming bacterium that has been studied for its potential to improve digestion and boost immune function.

Bacillus amyloliquefaciens is another species of Bacillus that is commonly found in soil. It has been shown to improve gut health by promoting the growth of beneficial bacteria and reducing the growth of harmful bacteria.

Bacillus cereus is a species of Bacillus that is found in soil and contaminated food. While some strains of Bacillus cereus can cause food poisoning, others have been studied for their potential use as probiotics to improve gut health.

Bacillus firmus is a species of Bacillus that is found in soil and fermented foods. It has been studied for its potential to improve gut health and reduce inflammation.

Bacillus licheniformis is another species of Bacillus that is commonly found in soil. It has been shown to improve gut health by promoting the growth of beneficial bacteria and reducing the growth of harmful bacteria.

Bacillus magentarium is a species of Bacillus that is found in soil and has been studied for its potential to improve gut health and reduce inflammation.

Bacillus stearothermophilus is a thermophilic species of Bacillus that is commonly used in industrial applications. While it is not commonly used as a probiotic, it has been studied for its potential to improve gut health.

Bacillus thuringiensis (Bt) is a species of Bacillus that is commonly used as a biological pesticide. While it is not commonly used as a probiotic, some studies have suggested that certain strains of Bt may have probiotic potential.