Prebiotics and Probiotics

Published 12/16/2013. Last updated 2/5/2014.

PROBIOTICS are helpful, live bacteria and/or yeasts that stimulate the growth of beneficial microorganisms in the gut. They are found in fermented foods such as kefir, live-culture yogurt, sauerkraut, kimchi, kombucha and real pickles (not ones made with vinegar). If our gut flora has already become seriously out of balance, we can also benefit from taking high quality probiotics as supplements to populate the necessary array of probiotics in our guts.

PREBIOTICS are complex sugars (such as inulin and other fructo-ogliosaccharides)  that are indigestible by humans but promote the growth of beneficial bacteria already in our guts – the probiotics – by serving as fuel for them. We get prebiotics from fruits, vegetables and whole grains – or supplements. Sometimes prebiotics and probiotics are combined in the same product, called SYNBIOTICS.


In the centuries before we had refrigeration or freezing, foods were often preserved by fermentation.  In eating and drinking those fermented foods, we regularly ingested prebiotics and probiotics that kept our gut flora balanced and happy.
Live, lactic acid fermentation is the simplest and usually the safest way of preserving food. Before we had refrigeration, canning and chemical preservatives, humans in every culture preserved foods by fermenting them – sauerkraut, tempeh (fermented soybeans), miso (fermented soybean paste), kimchi, dry sausages, pickles, cheeses, yogurt, kefir, sourdough bread starters, beers and wines, among others.
We pretty much stopped eating those digestion-enhancing foods when we started relying on foods kept ”fresh” by refrigeration and other artificial means – and even worse, started eating heavily processed, essentially fake and genetically altered foods. What we gave up in turning away from fermented foods was ingesting enough of the friendly bacteria our bodies need to maintain good health, the prebiotics and probiotics created by natural fermentation. (Hardin, 2011)
Natural fermentation develops vast amounts of lactic acid bacteria, friendly bacteria our guts need to maintain good health. Take sauerkraut for example: The numbers of different lactic acid bacteria in live sauerkraut can reach concentrations of 10 (to the 8th) to 10 (to the 9th) per gram. ( Zdenka Samish,  1963), whose mission is ‘To identify the best quality health and nutritional products through independent testing’, posts an extensive review of Probiotics for Adults, Children and Pets on its website. The full report is available only to subscribers but you can see a summary here. I highly recommend either becoming a subscriber or paying $18 to get the entire report with its wealth of information on which probiotics to take for specific conditions; how to choose  probiotics for yourself, your children and pets; and a chart of their testing results for of 41 probiotic supplements listed alphabetically by brand, the amounts/types of probiotics they contain, and whether they contain GMO products, gluten, milk, or yeasts.
According to the ConsumerLab chart, Dr Mercola’s Complete Probiotics is a good choice as a general supplement. Two capsules/day contain a high concentration of live probiotics – and no dairy, wheat, gluten or yeast. The 10 probiotic strains found in this supplement are listed about half way down on this page on the Mercola website.
See Chapter 11 in Bacteria for Breakfast by Kelly Karpa for a discussion of which probiotics are most effective for treating which health issues. I highly recommend the rest of the book too. It’s easy to read and chock full of helpful information on how probiotics support immune function, prevent uro-genital infections and maintain good GI health in general. Dr Karpa is a pharmacist, researcher and award-winning educator. (Karpa, 2006)