There are a lot of buzzwords around gut health, and the various players in the microbial universe. Here are a few basic terms to educate yourself:

Meet the ‘Biotics family!

Prebiotics

Foods containing substances (mostly fibers) that we cannot digest, but which feed our good microbes.

Probiotics

Live bacteria that confer a health benefit when ingested. Found in raw fermented foods like sauerkraut, kimchi, yogurt, kombucha, miso, certain cheeses, pickles, kefir and probiotic pills. Learn more about the history of probiotics.

Synbiotics

A combination of synergistic prebiotics and probiotics; usually in a supplement form

Psychobiotics

Live microorganisms that confer health benefits to people with psychiatric illnesses such as anxiety and depression. (A subset of probiotics.) Major genera include Lactobacillus and Bifidobacteria.

Here’s a great book on the subject.

Postbiotics

The metabolic byproducts of probiotic bacteria such as acetate, butyrate, and propionate. these are short chain fatty acids which are used as energy by the host (us!)

Note that even a healthy gut contains pathogenic organisms (bacteria, fungi, and viruses*). Like any healthy ecosystem, they are kept in check by the “good” guys.

* if they exist