Probiotics Are Overhyped, What You May Need More of is Prebiotics


Not all bacteria cause illness. Some function more as “good guys.” In fact, there’s a universe of bacteria in your gut, called the microbiome, and they help keep your gut and immune system healthy. When the 70% of your immune system that lies in your gut gets out of balance, it can lead to short-term issues, like diarrhea and digestive upset, but when these bacteria remain out of whack it can possibly contribute to long-term health problems as well.

One common way gut bacteria get out of balance is from taking antibiotics. Some research suggests that microbiome recovery from a single course of antibiotics may take months or even years, depending upon the antibiotic, the person’s age, and the individual. Plus, it preliminarily looks like the gut microbiome plays a role in body weight, possibly by impacting appetite and metabolism. Early studies also reveal that obese people have a less diverse microbiome. Although it’s not clear which bacteria offer the most health benefits, a more diverse microbiome appears to be healthiest.

With so much focus on the microbiome, it’s not surprising that probiotic supplements are growing more popular. These supplements attempt to provide your gut with a diversity of bacteria that, according to preliminary research, offer the most health benefits. The idea is that when you swallow a probiotic pill, the tiny organisms in the pill take up residence in your gut and become a part of your microbiome. However, some studies suggest that swallowing a pill containing probiotics may not offer the same benefits as modifying your microbiome through diet.

The Problem with Probiotics

One concern about probiotic supplements is that not everyone responds the same to them. Some people appear to have a microbiome that “fights” the addition of new bacteria to the gut, possibly seeing these as foreign invaders. In these people, the bacteria in a probiotic supplement don’t colonize the gut but are excreted by the body. The body rejects them. Therefore, some people may be resistant to probiotics in supplement form and gain no benefit from taking them. Plus, although some people experience improvements in digestive health when they take probiotics, others experience side effects like bloating.

Why Changing Your Diet Is a Better Approach

If swallowing a probiotic pill isn’t reliable, the other option is to change your diet. One approach is to consume more probiotic-rich foods. These include fermented foods that are naturally high in bacteria. Examples are kefir, kombucha, yogurt, and fermented vegetables. The best-known fermented vegetable is unpasteurized sauerkraut, but you can ferment a variety of vegetables to increase their healthy bacterial count. But there’s another approach that offers benefit and it might be your best bet for supplementing your microbiome. It’s adding prebiotic-rich foods to your diet.

What are prebiotics? Prebiotics is the fiber that gut bacteria feed on and depend on to survive and thrive. Plant-based foods contain fiber, but not all fiber in plants is prebiotic. Fiber falls into two classes: soluble and insoluble fiber. It’s the soluble fiber that has prebiotic potential. When bacteria feed on prebiotic fiber, they ferment the fiber and produce short-chain fatty acids such as butyrate, acetate, and propionate. These weak acids appear to have an anti-inflammatory effect on the walls of the colon. In fact, animal studies suggest that these weak acids produced by bacteria in the gut may lower the risk of colon cancer. You won’t get these benefits by popping a probiotic pill.

Unfortunately, most people fall short of getting the recommended amount of fiber daily, painfully short! The current guidelines say we should get 25 to 35 grams of fiber each day. The average person gets only 15 grams. The reason may be the highly processed diet many people eat. Processed foods are usually low in fiber and the fiber that’s in there is synthetic fiber added back in to compensate for the fiber removed during processing. The key to getting enough fiber is to eat more plant-based foods.

In terms of foods with prebiotic potential, some of the best sources include onions, garlic, artichokes, wheat bran, flaxseed, barley, leeks, legumes, oats, almonds, and bananas. Including these foods and more plants in general in your diet can help you boost the population of healthy bacteria in your microbiome.

Your Microbiome Can Change Quickly

How effective are dietary changes at boosting the microbiome? One study found that switching from an animal-based diet to a plant-based boosted the number and diversity of bacteria in the gut after only four days.  That’s quicker than the effect you would likely get from a probiotic supplement and it’s a more reliable approach. By consuming more prebiotic fiber, you create an environment that fosters the growth of healthy gut bacteria.

Other Problems with Taking a Probiotic Supplement

Since probiotic supplements aren’t closely regulated, so you have to depend on the manufacturer to use good quality practices to ensure there’s no contamination of their products. In 2014 a probiotic supplement contaminated with a fungus killed a premature infant. Plus, probiotics may be unsafe for people with immune system problems. Also, due to lack of regulation of supplements, almost anyone can private label a probiotic supplement and sell it on sites like Amazon. You don’t always know what you’re getting and whether the bacteria in a probiotic supplement are still alive and viable.

It’s also not clear yet what conditions probiotics are beneficial for. Studies suggest that the greatest evidence lies with probiotics for conditions such as diarrhea due antibiotic use, certain types of respiratory conditions, inflammatory bowel disease, and irritable bowel syndrome. For other conditions and for prevention of other conditions, we still need more research.

Some people take a probiotic supplement to help replenish bacteria destroyed after taking antibiotics, but a recent study suggests that probiotics may actually interfere with gut recolonization and return to the pre-antibiotic microbiome.

The Bottom Line

Unless your physician recommends it, skip the probiotic supplements and focus on adding more prebiotic foods to your diet. Fermented vegetables, such as sauerkraut, have the benefit of offering both prebiotic fiber and live probiotic organism – and that’s a win-win!



·        MMWR Morb Mortal Wkly Rep. 2015 Feb 20; 64(6): 155–156.

·        Cell. Volume 174, Issue 6, P1406-1423.E16, September 6, 2018.

·        The Lancet Gastroenterology and Hepatology. “Probiotics: elixir or empty promise?”

·        Nutr Today. 2016 Jul-Aug; 51(4): 167–174.


Related Articles By Cathe:

Prebiotics: Keeping Your Intestinal Flora Healthy

Probiotics and Prebiotics: What’s the Difference and Why Does It Matter?

Can Endurance Exercise Change Your Gut Microbiome?

Does All Yogurt Contain Probiotics and Active Cultures?

The Problem with Probiotic Supplements: Are They What They Seem to Be?

Can Probiotics Help with Exercise Recovery?

Are Probiotic Supplements Overhyped?

4 Science-Backed Reasons to Add More Fermented Vegetables to Your Diet

Share on facebook
Share on twitter
Share on pinterest
Share on email
Hi, I'm Cathe

I want to help you get in the best shape of your life and stay healthy with my workout videos, DVDs and Free Weekly Newsletter. Here are several ways you can watch and work out to my exercise videos and purchase my fitness products:

Get Your Free Weekly Cathe Friedrich Newsletter

Get free weekly tips on Fitness, Health, Weight Loss and Nutrition delivered directly to your email inbox. Plus get Special Cathe Product Offers and learn about What’s New at Cathe Dot Com.

Enter your email address below to start receiving my free weekly updates. Don’t worry…I guarantee 100% privacy. Your information will not be shared and you can easily unsubscribe whenever you like. Our Privacy Policy