Prebiotics: How to feed your friendly gut flora

By: Dr. David Friedman

Probiotics have earned much attention in recent health news for their gut protecting benefits. If you’re not yet familiar with them, probiotics are the healthy bacteria living in your digestive tract (and other areas of your body, too) helping to break down food, absorb nutrients, and keep out bad bacteria and infection. These good bacteria are referred to as your microbiome, and the amount of bacterial cells that compose it actually outnumber the amount of human cells in your body.

While we inherently have these happy bacteria in our bodies, they can decline thanks to things like antibiotics, a poor diet, and environmental toxins. Eating fermented foods like yogurt, sauerkraut, and kombucha are nutritionally sound ways to increase your probiotic intake. These bacteria play an extremely important role in human health, so it’s important to keep them thriving. To learn more about probiotics read my previous article.

Why Probiotics Aren’t the Whole Story

While eating certain foods can provide you with probiotics, it doesn’t necessarily mean they will survive the journey through your complex digestive system or even repopulate within it to keep your microflora going strong. One really helpful way to support this process is to focus on eating prebiotics as well. Prebiotics are what probiotics eat; they come from certain types of fiber that pass through the small intestine undigested. This allows them to make it all the way to the colon (where the majority of gut bacteria live) so that they can be fermented into fuel for those beneficial bacterial cells to live on.

Benefits of Prebiotics

 We’ve known for a long time that dietary fiber boasts all sorts of health benefits, like supporting a lower body weight and reducing the risk for cardiovascular disease. It makes sense, then, to see that prebiotics also have health promoting effects, since they come from various fibrous sources, most commonly as fructooligosaccharides (FOS), but also as inulin and resistant starch. Probiotics provide many different health benefits– from boosting the immune system and balancing mood, to promoting health hormones – they do a lot for our overall wellness. Assisting our probiotic balance with a healthy dose of prebiotics will further support all of these beneficial processes.

Prebiotic fibers have been shown to boost the growth of beneficial probiotic bacteria, specifically lactobacilli and bifidobacteria. These probiotics play a huge role in keeping our bowels moving regularly and helping to eliminate toxins – a major component to whole-body health. Changes in the microbiome have been linked to many symptoms and diseases, such as diarrhea, constipation, inflammatory bowel disease, and Candida overgrowth, and have been shown to decline in severity when a synbiotic (a combined probiotic and prebiotic supplement) is taken. Prebiotics have been linked to weight loss, as they alter the composition of various types of bacteria that are associated with lean body mass. Prebiotic fiber is also beneficial with weight management because of its satiating effect. Not only does it make you physically feel fuller but it’s also been found to positively impact satiety hormones, giving your brain and belly the signal to stop eating.

You might be surprised that non-gastrointestinal issues can also benefit from synbiotics, such as allergic rashes, respiratory infections, and urogenital complaints. Research has even found synbiotics can reduce the effects of lactose intolerance, as well as cancer promoting enzymes found in the gut. Over 70% of our immune system is located in out gut, which makes it clear that a balanced microbiome does more for us than just promote good digestion.

Prebiotic Rich Foods

Some of your everyday favorite foods are great sources of prebiotics. Bananas are one tasty option, which actually contain more prebiotic resistant starch when they are on the greener side of ripe. Whole-grain corn is another, so your homemade popcorn with coconut oil with sea salt is actually supporting a healthy bacterial composition in your gut. A study from the International Journal of Molecular Science shows that many kinds of mushrooms also contain several types of prebiotic carbohydrate compounds. White button mushrooms have specifically been found to directly enhance microbial diversity and resolve certain types of bacterial infections. Whole oats offer great prebiotic benefits. They contain large amounts of beta-glucan fiber, as well as some resistant starch. Beta-glucan from oats has been linked to healthy gut bacteria, lower LDL cholesterol, better blood sugar control and reduced cancer risk. Raw dandelion greens, raw garlic, and raw onions are other delicious prebiotic options to include in your weekly meals.

While it may be shocking that we rely on trillions of bacterial cells to help our body function at its best, this symbiotic relationship of probiotics and prebiotic is one that should truly be recognized and encouraged if you want to support optimal health.

References

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 Chonan O, Takahashi R, Watanuki M. Role of activity of gastrointestinal microflora in absorption of calcium and magnesium in rats fed beta1-4 linked galactooligosaccharides. Biosci Biotechnol Biochem. 2001 Aug;65(8):1872-5.

 Markowiak P, Slizewska K. Effects of Probiotics, Prebiotics, and Synbiotics on Human Health. Nutrients. 2017 Sep 15;9(9). doi: 10.3390/nu9091021.

Jayachandra M, Xiao J, Baojun X. A Critical Review on Health Promoting Benefits of Edible Mushrooms through Gut Microbiota. Int. J. Mol. Sci. 2017, 18(9), 1934; doi:10.3390/ijms18091934.

Parnell JA, Reimer RA. Prebiotic fibres dose-dependently increase satiety hormones and alter Bacteroidetes and Firmicutes in lean and obese JCR:LA-cp rats. Br J Nutr. 2012 Feb;107(4):601-13. doi: 10.1017/S0007114511003163. Epub 2011 Jul 18.

Valeur Jr et al.  Oatmeal Porridge: impact on microflora-associated characteristics in healthy subjects.  British Medical Journal 2016 Jan 14; 115(1):62-7 doi 10.1017/S0000711451500423 Epub 2015 Oct 29