* Lactobacillus: Found in yogurt, sauerkraut, and other fermented foods, these bacteria help with digestion and can contribute to a healthy gut microbiome.
* Bifidobacterium: Another common probiotic found in yogurt, these bacteria also aid in digestion and can help with immune function.
* Bacillus subtilis: This bacteria is often used as a soil inoculant, helping plants access nutrients more efficiently. It's also used in some fermented foods and is thought to have potential benefits for human health.
* Escherichia coli (E. coli) K12: While some strains of E. coli can be harmful, the K12 strain is considered safe and is widely used in research and biotechnology.
* Nitrobacter: This bacteria plays a crucial role in the nitrogen cycle by converting nitrite to nitrate, making nitrogen available to plants.
It's important to remember that even "good" bacteria can become harmful in certain situations. For instance, if a person's immune system is compromised, even harmless bacteria could cause illness.
