The Power Of Postbiotics: What They Are & How They Support Our Overall Health
The link between the gut microbiome and overall human health is a hot area of scientific research, which is why you're likely familiar with prebiotics and probiotics. But I'd be willing to wager you haven't paid much attention to the "biotics" that may matter the most: postbiotics.
What is a postbiotic?
While the scientific community is still debating the exact definition of postbiotics, broadly speaking, the term refers to compounds resulting from the microorganisms in our gut1.
Our gut microbiome consists of bacteria, yeast, fungi, viruses, and archaea, which thrive in this nutrient-rich environment. These organisms metabolize and convert properties from the food we eat into active substances (postbiotics) that have a health benefit for the host.
A challenge with these substances is that even after taking pre- and probiotics, many people don't have the right microbiome to produce optimal amounts of postbiotics, which is why supplementation is emerging as a unique solution.
There are several different postbiotic compounds2 that have already been identified. These include short-chain fatty acids (SCFAs), vitamins, polysaccharides, proteins, and lipids—each exerting its own beneficial effect. While researchers are still discovering the many ways postbiotics affect our health, the following have been well studied with promising results demonstrating their benefits.
Postbiotics & their effect on human health:
Urolithin A for mitochondrial health
Mitochondria are the powerhouses inside our cells, generating most of the energy we need to function. Over time, oxidative stress and age contribute to the decline in mitochondrial function3, and our health suffers as a result.
Urolithin A4 is the first postbiotic shown to activate an essential repair process called mitophagy, where damaged mitochondria are cleared away and renewed. A recent study at the University of Washington School of Medicine in Seattle showed that supplementing with a pure form of Urolithin A improved mitochondrial function5 and also improved hand and leg muscle endurance in older adults when compared to placebo.
While Urolithin A is a naturally occurring postbiotic derived from the polyphenolic compounds in pomegranates, nuts, and berries, an earlier study showed that only 30% to 40% of people are able to convert these compounds into enough levels of Urolithin A. This is likely due to the highly personalized nature of the gut microbiome. On average, the supplement provided people with six more Urolithin A than a glass of pomegranate juice6—hence the emerging interest in supplementing with a pure form of this postbiotic.
Direct supplementation with Urolithin A overcomes limitations of dietary exposure and gut microbiome variability in healthy adults to achieve consistent levels across the population.
Butyrate for improved digestion
Short-chain fatty acids, including butyrate, propionate, and acetate, are produced by fiber fermentation in the colon. They are an important source of energy for the cells of the digestive tract and therefore play a crucial role in the turnover and renewal of the intestinal lining.
These postbiotics may help preserve the integrity of the intestinal barrier7, making them helpful in treating inflammatory bowel disease and other digestive disorders. Additionally, SCFAs are being studied8 for their use in preventing cancer growth, supporting healthy blood sugar levels, and modulating immune function.
Equol for postmenopausal health
Equol is a postbiotic that has shown promise in supporting women's postmenopausal health. A small study demonstrated that intestinal bacteria could convert an isoflavone found in soybeans into equol, a postbiotic compound with a similar structure to estrogen. The study found that equol functioned like a weak alternative to estrogen and was able to help reduce the number and severity of hot flashes in peri- and postmenopausal women.
However, studies from early in the 2010s9 showed that only 30 to 60% of the Japanese population could convert soy isoflavones to equol and therefore were not able to get the health benefits associated with this postbiotic. Just like with Urolithin A, this may need to be taken as a supplement in order to get maximal benefit.
Beta-glucans for immune support
Some types of postbiotics appear to interact with the cells of the immune system. Specifically, beta-glucans (β-glucans) may support the cellular response to pathogens like parasites, bacteria, and viruses.
Beta-glucans are a polysaccharide structural component of the cell wall of fungi, yeast, and some bacteria. They also are found in cereals such as oats and barley. These compounds are detected by receptors in the intestines and stimulate an immunologic response10. Studies have shown that beta-glucans can modulate the activity of immune cells11, activating their antimicrobial activity. They also support health by increasing the absorption of carotenoids, antioxidants with anti-inflammatory properties, and promoting the adherence of healthy bacteria to the gut lining. These immune modulators are being studied for their use as a treatment for several immune-related conditions.
Postbiotics are the next frontier of understanding the gut microbiome. As research continues to unfold, postbiotic therapy is likely to become an important tool in treating a wide variety of health conditions, from improving immunity to promoting healthy aging.
Marvin Singh, M.D is an Integrative Gastroenterologist in San Diego, California, and a Member of the Board and Diplomate of the American Board of Integrative Medicine. He is also trained and board certified in Internal Medicine and Gastroenterology/Hepatology. A graduate of Virginia Commonwealth University School of Medicine, Singh completed his residency training in Internal Medicine at the University of Michigan Health System followed by fellowship training in Gastroenterology at Scripps Clinic Torrey Pines. Singh was trained by Andrew Weil, M.D., a pioneer in the field of integrative medicine, at the Andrew Weil Center for Integrative Medicine.
Singh is currently the Director of Integrative Gastroenterology at the Susan Samueli Integrative Health Institute at UC Irvine. He is also currently a voluntary Assistant Clinical Professor at UCSD in the Department of Family Medicine and Public Health; prior to this, he has been a Clinical Assistant Professor at UCLA and an Assistant Professor of Medicine at Johns Hopkins University. Singh is a member of the American Academy of Anti-Aging Medicine, American College of Lifestyle Medicine, and many other societies. He is actively involved in the American Gastroenterological Association. He is one of the editors of the textbook of Integrative Gastroenterology, 2nd edition (a Weil Series text) and has written several book chapters and articles.
He is dedicated to guiding his clients toward optimal wellness every step of the way, using the most cutting edge technologies to design highly personalized precision based protocols. Towards this end, he founded Precisione Clinic and wrote the book Rescue Your Health to bring the best in preventive medicine to his clients.