Beneficial Bacteria for Humans: Probiotics, Prebiotics and Postbiotics

Probiotics are among the hottest supplements of 2019 and with good reason. The positive role of these “good” bacteria are being revealed in everything from digestive health to brain support on an almost-daily basis.

Learn more about probiotics, prebiotics and postbiotics below, or listen to the podcast on in which Life Extension’s own Michael A. Smith, MD, discusses the latest information concerning probiotics with nutrition expert Crystal Gossard, DCN, CNS, LDN.

While most of us are familiar with antibiotics, not everyone knows exactly what probiotics are. While antibiotics reduce or stop the growth of bacteria, probiotics are bacteria. The difference between these bacteria and those we seek to combat with antibiotics is that probiotic microorganisms are beneficial to the body, and therefore desirable, while those we want to treat with antibiotics are, of course, potentially harmful.

What are probiotics good for?

Probiotics colonize the intestinal tract and support gastrointestinal health, including digestion. We are learning more all the time about how they can benefit not only the GI tract, but the entire body. In fact, there are an estimated 10 times more microbial cells in the human body than human cells.1 Many of these microorganisms are the beneficial bacteria known as probiotics.

Common Probiotics and Probiotic Strains

Probiotic bacteria are classified by genus, species and strain. Two common genera are Lactobacillus and Bifidobacterium. Other genera include Escherichia, Enterococcus, Bacillus, Propionibacterium, Streptococcus, Pediococcus, Leuconostoc and Saccharomyces. Common Lactobacillus species are acidophilus, bulgaricus, casei, fermentum, plantarum and rhamnosus, and better-known Bifidobacterium include animalis, bifidum, breve, infantis, lactis and longum. Following these species names may be a number or letter designating the strain, as in Lactobacillus acidophilus NCFM.

Best Foods for Gut Health: Foods High in Probiotics

Yogurt is the most well-known food that contains one or more probiotic cultures. Other foods that contain probiotics include fermented products such as kimchi, miso, sauerkraut, kombucha, kefir, buttermilk, some cheeses and sourdough. Probiotics are also available in supplement form.

Probiotics Supplements: Multiple Strains

Probiotics in supplemental form are capsules, liquids or lozenges that contain concentrated amounts of probiotic bacteria. Popular probiotic species are Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus bulgaricus, Bifidobacterium infantis and Bifidobacterium bifidum, among others. Many supplements contain several strains to support a specific area of concern or general well-being.

Why take probiotics?

Probiotics help maintain healthy intestinal flora by limiting the overgrowth of potentially harmful bacteria. The balance of bacteria that live in our intestines is important for digestive and immune health.2 Probiotic bacteria may also help control the overgrowth of fungi such as Candida albicans, not only in the intestines, but in the mouth and other areas.3

Probiotics have been used around the world for many years in various forms. The legendary longevity benefits attributed to probiotic foods such as kefir might have a basis in their recently revealed health properties. While not everyone likes yogurt or sauerkraut, and kimchi may be hard to find, consuming a probiotic capsule is an easy way to encourage healthy microflora.

How do probiotics affect the brain?

The beneficial effect on mental states that may be associated with probiotics is facilitated by signaling between the digestive tract and the brain.4 The gut and brain communicate through the vagus nerve, endocrine signaling mediators and the immune system.

It has been observed that Alzheimer’s disease and Parkinson’s disease patients have a high incidence of gastrointestinal disorders.5,6 Unfavorable alterations in gut microflora may result in greater permeability of the gut barrier, potentially leading to immune activation and systemic inflammation. This can impair the function of the blood-brain barrier, thereby causing neuroinflammation and neurodegeneration.7 Therefore, management of intestinal flora may help support brain health.

An article published in 2019 – “Man and the microbiome: a new theory of everything?” – observes that the gut microbiome has been implicated in a variety of psychological disorders. “Preclinical studies have provided us with key insights into the mechanisms by which the microbiome influences bidirectional gut-brain communication,” the authors write. “The complex and widespread influence of the microbiome on many physiological and psychological processes has generated a keen interest in its therapeutic potential for depression, anxiety, autism, and other psychiatric disorders. It has been shown that the microbiome composition of people suffering with such conditions differs significantly from that of healthy controls, and although the area is in its infancy, interventional studies that alter a person's microbiome through the use of probiotics, prebiotics, or dietary change can alleviate psychopathological symptoms.”8

The Difference Between Prebiotics and Probiotics

Prebiotics act as food for probiotic bacteria. Inulin from chicory and fructo-oligosaccharides (FOS) from inulin are common prebiotic supplements that nourish probiotics. Other prebiotics include beans, legumes, starchy fruits, cereals, onions and other vegetables, as well as other foods such as milk and fungi.9 Polyphenols such as resveratrol and anthocyanins also have prebiotic properties.9

What are postbiotics?

Postbiotics have been defined as “those molecules released by bacteria and other microorganisms that, when administered in adequate amounts, confer health benefits to the host.”10 It is the opinion of the author of this definition that greater benefit may be derived from the ferment of fermented foods than the bacteria present in the foods: “The many nutrients the bacteria make, what I call the postbiotics, while fermenting the foods, are what are beneficial to the GI and the immune system.”10

Postbiotics are nonliving compounds that have a long shelf life. Among the hundreds of postbiotics are peptides and the short-chain fatty acids acetate, butyrate and propionate.

What are Phages and How Do They Work?

“Phages” is a short way of saying “bacteriophages,” which describes submicroscopic packages of DNA or RNA enclosed in a protein envelope that target bacteria. Certain bacteriophages selectively target specific undesirable bacteria while leaving beneficial bacteria undisturbed.

Bacteriophages were discovered over 100 years ago and are generating renewed interest in the face of antibiotic resistance.11

Bacteriophage Probiotic: What is phage therapy?

Phage therapy involves the use of bacteriophages in the treatment of bacterial infections. Phages can also be used preventively. Combining phages with probiotics may reduce the growth of undesirable bacteria, allowing the beneficial probiotic bacteria to thrive.

About Live Foreverish: Join Dr. Mike as he sits down with some of today’s leading medical, health and wellness experts to discuss a variety of health-related topics. From whole-body health to anti-aging and disease prevention, you’ll get the latest information and advice to help you live your life to the fullest. If you like what you hear, please take a moment to give Live Foreverish a 5-star rating on iTunes!

  1. Turnbaugh PJ et al. Nature. 2007 Oct 18;449(7164):804-10.
  2. Alarcón P et al. Rev Med Chil. 2016 Jul;144(7):910-6.
  3. Rossoni RD et al. Biofouling. 2018 Feb;34(2):212-225.
  4. Breit S et al. Front Psychiatry. 2018 Mar 13;9:44.
  5. Westfall S et al. Cell Mol Life Sci. 2017 Oct;74(20):3769-3787.
  6. Sarkar S et al. J Neuroimmunol. 2019 Mar 15;328:98-104.
  7. Kowalski K et al. J Neurogastroenterol Motil. 2019 Jan 31;25(1):48-60.
  8. Butler MI et al. Annu Rev Clin Psychol. 2019 Feb 20.
  9. Reynés B et al. Front Physiol. 2019 Jan 10;9:1908.
  10. Maguire M et al. Rev Neurosci. 2019 Jan 28;30(2):179-201.
  11. Kortright KE et al. Cell Host Microbe. 2019 Feb 13;25(2):219-232.


Unknown said...

Very good explanation. Thanks!

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