Prebiotics
DEPräbiotika
A prebiotic is food for your good gut microbes. The official definition comes from ISAPP (the International Scientific Association for Probiotics and Prebiotics). It is a substrate that your microbes selectively use to give you a health benefit. That definition is deliberately broad. It covers fermentable fibers like inulin, fructooligosaccharides, and galactooligosaccharides. It also covers some non-carb compounds and uses beyond the gut. And it demands proof of two things. First, that microbes selectively use it. Second, that it gives a real health benefit. Well-studied prebiotics reliably grow Bifidobacterium and Lactobacillus species. They also boost short-chain fatty acids (SCFAs) and firm up stool. Effects on harder outcomes, like blood-sugar control and immunity, are modest and show up only in some trials. A prebiotic is also not the same as fiber in general. Fiber is fermented broadly by many microbes. A prebiotic has to clear that stricter 'selective' bar.
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This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer