The Health Benefits of Prebiotics and Probiotics
Probiotics are one of the most popular dietary supplements in the United States, and their use continues to grow. According to a Zion Market Research report, the global probiotics market is expected to generate revenue of around USD 65.87 billion by the end of 2024. While you’ve probably heard of probiotics, do you know about prebiotics? These two terms sound very similar, but they each play different roles in the human body. Moreover, prebiotics and probiotics can provide several health benefits and have been studied for the treatment of a variety of diseases. To learn more about the health benefits of prebiotics and probiotics, keep reading below.
What are probiotics?
Probiotics are live microorganisms, such as bacteria and yeasts, that are good for you. A few examples of good bacteria include Lactobacillus acidophilus, Saccharomyces boulardii, and Bifidobacterium bifidum. Probiotics are available as dietary supplements and also occur naturally in certain foods. Examples of probiotic foods include yogurt, kefir, sauerkraut, kimchi, kombucha, and apple cider vinegar.
Gut microbiota, also referred to as gut flora, is the name given to the microbe population living in our intestine. Interestingly, the gut microbiota contains tens of trillions of microorganisms, including at least 1000 different species of known bacteria. When consumed, probiotics add specific strains of bacteria to the population of healthy microbes in your gut. Generally speaking, probiotics are responsible for nutrient absorption and supporting your immune system. We will discuss the health benefits of probiotics in detail below.
What are prebiotics?
Prebiotics are a type of non-digestible fiber compound that provide indirect benefits by enhancing the growth or activity of beneficial microorganisms (probiotics) in the digestive tract. Prebiotics are available as dietary supplements and also occur naturally in certain foods. Prebiotics include conjugated linoleic acid, polyunsaturated fatty acid, human milk, and a type of dietary fiber called oligosaccharides. (i.e. fructooligosaccharides, galactooligosaccharides, inulin, mannan-oligosaccharide, and xylooligosaccharide). Prebiotics are found in many fruits and vegetables, especially those that contain complex carbohydrates. Similar to other high-fiber foods, prebiotic compounds pass through the upper part of the gastrointestinal tract and remain undigested because the human body cannot fully break them down. Instead, prebiotics pass through to the large intestine where they stimulate the growth of Bifidobacteria (a good bacteria) by acting as a food source. Essentially, prebiotics can be thought of as a source of fuel for the good bacteria in your gut.
Health benefits of prebiotics and probiotics
Now that you know the role of prebiotics and probiotics in the human body, let’s dive into the health benefits of prebiotics and probiotics.
Prebiotics work synergistically with probiotics to enable specific changes to take place, both in the composition and activity of the gastrointestinal system. They play a fundamental role in preserving health by maintaining balance and diversity of intestinal bacteria, especially by increasing the presence of good bacteria. Since the health of your gut is closely tied to many other bodily functions, prebiotics and probiotics together are important for lowering overall disease risk.
While both prebiotics and probiotics provide health benefits, probiotics have been studied more closely for the prevention and treatment of certain disease. For instance, the use of probiotics has been evaluated for the treatment of hypertension, hyperlipidemia, obesity, allergic rhinitis, atopic dermatitis in infants, and type II diabetes. While probiotics have been evaluated for a wide range of diseases, gastrointestinal (GI) disorders have the most evidence of benefit. Below are a few examples of conditions in which the use of probiotics have demonstrated benefit.
Antibiotic-associated diarrhea: The bacteria Saccharomyces boulardii (found in the product Florastor) and Lactobacillus have both been extensively studied for the prevention of antibiotic-associated diarrhea. Saccharomyces has had the most consistent results during clinical studies. It is recommended to start taking a probiotic within two days of starting an antibiotic and to continue for three days after antibiotic treatment has ended.
Rotaviral Diarrhea: Rotavirus is a potentially severe infection that is highly contagious among infants and young children, with one of the most common symptoms being severe diarrhea. Since this condition is caused by a virus, treatment consists of supportive care and oral rehydration solution to prevent or treat dehydration. There is a theory that administering probiotics can shorten the duration of rotaviral diarrhea since the good bacteria can block the adhesion of rotaviruses to the surface of the intestines. Lactobacillus GG (found in the product Culturelle) is the most well-studied probiotic for rotaviral diarrhea, and it has been shown to reduce the duration of the diarrheal phase of rotavirus infection by one to three days in infants and young children.
Irritable Bowel Syndrome (IBS): IBS is a common disorder that affects the large intestine. The most common symptoms include abdominal pain, altered bowel habits, and sensations of bloating. Patients with IBS are known to have alterations in the gut flora, however, it is unclear if this is a cause or consequence of the condition. Studies have found that probiotics seem to moderately improve symptoms of IBS, particularly abdominal pain. The bacteria strain Bifidobacterium infantis (found in products such as Align or Bifantis) has shown the most promise in effectively reducing IBS symptoms, including abdominal pain, bloating, and bowel movement difficulty within one week of treatment.
So can probiotics provide health benefits if you do not have one of these conditions? Yes, they can! Research has shown that probiotics can improve gut barrier integrity and aid in digestion. Certain types of probiotics compete with pathogens (bad bacteria and viruses) to prevent their attachment, as well as stimulate the production of substances that inhibit pathogen growth. For example, some species of Bifidobacteria inhibit adherence of pathogenic E. coli and C. difficile to intestinal epithelial cells. Moreover, some probiotics produce short-chain fatty acids, which are known to provide anti-inflammatory effects and improve colon health.
What to keep in mind
There are a few things to keep in mind when it comes to prebiotic and probiotic supplements. One is that there are many, many different kinds. For instance, one type of bacteria commonly used is lactobacillus. But there are more than 120 species of lactobacillus, and at least a dozen of them are used as probiotics. Moreover, there are several other types of bacteria used in probiotic supplements, each with dozens of species.
Since choosing a probiotic supplement can be confusing, it’s important to first consult your doctor or pharmacist about your specific condition so that you can select the probiotic based on that condition. The benefit from a probiotic is not determined by the number of strains, but rather the right strains that have been shown to have benefit for a specific condition. Also, keep in mind that while a probiotic may show promising results in studies, it's likely that the research is still in early stages. While the supplement may have improved a condition for a few people in a very limited circumstance, it may not work as well in real-world settings.
If you have any further questions regarding anything that you have read here, or if you would like to share your experience with prebiotics and probiotics, please comment below.
PharmacyTimes.org, “The Expanding Health Benefits of Prebiotics and Probiotics”, Feb 2018
MayoClinic.org, “Prebiotics, probiotics and your health”
Dr. Axe, “13 Great Probiotic Foods You Should Be Eating”, Nov 2017
FoodRevolution.org, “Why You Need Both Probiotics and Prebiotics for Good Gut Health and Overall Wellness (Plus The Best Food Sources)” September 2018