If you’re a follower of health trends, you’ve probably noticed words like gut flora, microbiota, microbiome, prebiotics, and probiotics used frequently on TV, social media, book covers, and in the supplement aisles of your grocery store.
In today’s post, we’re going to take a look at how prebiotics and probiotics work. To do that, we’ll need to understand a bit more about our dedicated in-house team of microscopic assistants…
Microbiota: The Target of Prebiotics and Probiotics
Humans harbor a multitude of tiny helpful microorganisms throughout the body. The majority of these microbes are bacteria, fungi, and viruses that live within the gut, collectively known as “gut flora.” Although exact numbers have been debated, we have at least as many microbes living in (and on) our bodies as we have cells — trillions and trillions!
Humans have evolved to have a symbiotic relationship with these microbes, known collectively as the microbiota, and their genes altogether called the microbiome. We need their presence to live a healthy life.
Microbiota: The Spy Who Healed Me
Our gut microbiota help break down the foods we eat, including fibers we can’t usually digest. They are involved in helping to harvest energy and nutrients from this undigested food.
The microbiota is also critical for a healthy immune system, functioning as a sort of intelligence agency for the body’s defenses.
Scientists have shown that the presence of these microbes educates and influences the immune system. When a team of researchers created “germ-free” mice without a microbiota, their immune systems were poorly developed and dysfunctional. The gut has a large surface area, lined with specialized tissues that house a large percentage of the body’s immune cells.
You can see why the gut microbiota would be so influential on the function of the immune system!
Research has also shown that a higher diversity of gut microbes is associated with better health. Gut dysbiosis—a microbial imbalance in one’s gut—has been associated with many diseases. This includes metabolic disorders, inflammatory bowel diseases, autoimmune disorders, and even psychiatric and neurodevelopmental disorders such as depression and autism spectrum disorders. Dysbiosis can occur through exposure to antibiotics or other environmental or lifestyle factors such as poor diet, alcohol consumption, infections, hygiene practices, and excess stress.
Prebiotics: How to Be Good to Your Gut
What you feed your microbiota has a massive impact on its composition and diversity.
Prebiotics are non-digestible food ingredients that microbes can break down and ferment, which provide benefits for the host.
Those benefits include the production of short-chain fatty acids that have been found to have significant positive influences on human health. Common prebiotics include fiber and digestion-resistant starch; they can be found in many fruits, vegetables, grains, and other plant-based foods.
Foods listed with the highest amounts of prebiotic ingredients include:
● Jerusalem artichokes
● Garlic, onions, and leeks
● Legumes such as lentils, kidney beans, chickpeas and soybeans
● Banana (especially when slightly green)
● Grains such as oats, bran, and barley
Prebiotics are also sold in supplement form. The most common types are complex, indigestible sugars called fructo-oligosaccharide (FOS), galacto-oligosaccharides (GOS), and trans-galacto-oligosaccharides (TOS). Often, supplemental prebiotics are combined with a probiotic to provide more benefit as well as a synergistic effect.
Probiotics: Bringing Balance to the Force?
Probiotics are beneficial bacteria and yeast introduced either through foods such as yogurt or through supplementation.
The most common types of probiotics are Bifidobacterium and Lactobacillus. Others include the beneficial yeast Saccharomyces boulardii, and the bacteria Streptococcus thermophilus, often seen in yogurt cultures. There is some evidence to suggest that probiotics improve gut health. For example, they can promote the proper balance of microorganisms in the gut.
Probiotics can help restore the composition of microbiota after treatment with antibiotics.
They can help with diarrhea that often occurs when taking antibiotics. Probiotics can inhibit harmful microbes from setting up shop in the gut by providing a blockade and out-competing those harmful microbes for resources. Some probiotics can also produce substances, including enzymes and antimicrobial agents, that inhibit the survival and replication of pathogenic bacteria.
Probiotics can also promote health by providing nutrients and influencing the immune system.
Some probiotics naturally produce B vitamins and generate essential organic and amino acids. Beneficial bacteria are known to modulate immune responses through immune system stimulation, and recent studies suggest that certain probiotics may have benefits on metabolism, too.
Prebiotic and probiotic supplementation is growing in popularity as more research provides evidence of their beneficial effects. Understanding the myriad of ways in which the microbiota, prebiotics, and probiotics influence your body’s functioning can help you make proper dietary and supplement decisions!
Academic Journal Sources:
Spasova, D.S. and C.D. Surh, Blowing on embers: commensal microbiota and our immune system. Front Immunol, 2014. 5: p. 318.
Hooper, L.V., D.R. Littman, and A.J. Macpherson, Interactions between the microbiota and the immune system. Science, 2012. 336(6086): p. 1268-73.
Maruvada, P., et al., The Human Microbiome and Obesity: Moving beyond Associations. Cell Host Microbe, 2017. 22(5): p. 589-599.
Rapozo, D.C., C. Bernardazzi, and H.S. de Souza, Diet and microbiota in inflammatory bowel disease: The gut in disharmony. World J Gastroenterol, 2017. 23(12): p. 2124-2140.
de Oliveira, G.L.V., et al., Intestinal dysbiosis and probiotic applications in autoimmune diseases. Immunology, 2017. 152(1): p. 1-12.
Valles-Colomer, M., et al., The neuroactive potential of the human gut microbiota in quality of life and depression. Nat Microbiol, 2019. 4(4): p. 623-632.
Hughes, H.K., D. Rose, and P. Ashwood, The Gut Microbiota and Dysbiosis in Autism Spectrum Disorders. Curr Neurol Neurosci Rep, 2018. 18(11): p. 81.
Davani-Davari, D., et al., Prebiotics: Definition, Types, Sources, Mechanisms, and Clinical Applications. Foods (Basel, Switzerland), 2019. 8(3): p. 92.
Wilkins, T. and J. Sequoia, Probiotics for Gastrointestinal Conditions: A Summary of the Evidence. Am Fam Physician, 2017. 96(3): p. 170-178.
Markowiak, P. and K. Slizewska, Effects of Probiotics, Prebiotics, and Synbiotics on Human Health. Nutrients, 2017. 9(9).
Mazloom, K., I. Siddiqi, and M. Covasa, Probiotics: How Effective Are They in the Fight against Obesity? Nutrients, 2019. 11(2).