Prebiotics & Gut Health {+ Kimchi Recipe}

What Are Prebiotics?

Prebiotics have been gaining a lot of attention lately due to their impact on the health and diversity of the gut microbiome. Researchers and nutritionists in the mid-1990’s discovered prebiotics as they observed that certain soluble fibers such as inulin, oligofructose and fructo-oligosaccharides caused remarkable changes in the bacterial composition of the colon. Today, the International Scientific Association of Probiotics and Prebiotics (ISAPP) defines “dietary prebiotics” as “a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health." (1) In other (less scientific) words, prebiotics are fermentable dietary fibers that serve as nutrition for resident gut bacteria resulting in improved digestive, cardiovascular, cognitive, neurological and immune system health.

Health Benefits of Prebiotics

Prebiotics play an important role in human health. They naturally exist in breastmilk (to seed the gut of a newborn baby with healthy microbes) as well as in various plant foods (fructo and galacto-oligosaccharides). The best food sources of prebiotics are asparagus, leeks, garlic, onion, okra, artichokes, barley, rye, peas, beans, and seaweed.

As intestinal bacteria munch on prebiotic fibers, which human digestion is unable to fully break down, they release short-chain fatty acids (SCFAs). SCFAs include lactate, acetate, butyrate, and propionate which increase the acidity of the colon (lower the colonic Ph), improve intestinal absorption, and modulate the innate immune system to better defend the host against pathogenic organisms.

Short-chain fatty acids are also beneficial for improving the integrity of the gut lining. Butyrate in particular serves as a substrate (food) for colonocytes (cells lining the large intestine) and is involved in the development of the intestinal epithelium: a one-cell thick protection layer separating the intestinal lumen from the rest of your body preventing foreign substances like microbes, undigested food particles, and toxic molecules from entering the circulation. (2)