You may have heard of probiotics, the live microorganisms that, when ingested in adequate quantities, can benefit your health. Found in natural foods like yogurt, kefir, kimchi, and sauerkraut, they are also available as supplements.
For probiotics to thrive, they require nourishment, which comes from prebiotics. These are non-digestible fibers found in foods such as garlic, onions, leeks, bananas, and oats. Prebiotics move through the digestive system largely unchanged, serving as fuel for the beneficial bacteria in your gut.
Recently, you may have noticed another term gaining traction in the supplement aisle: postbiotics. But what exactly are they, and are they necessary for us?
Postbiotics are the beneficial substances created when gut bacteria, including probiotics, metabolize prebiotics. Essentially, these compounds are the final products of the bacteria’s activity, rather than the live organisms themselves. This category includes short-chain fatty acids, enzymes, vitamins, and amino acids, as well as fragments of bacterial cell walls and the remnants of dead microorganisms.
Despite the novelty of postbiotic supplements, postbiotics have existed as long as humans have had gut bacteria. What’s new is the idea of taking them as a supplement rather than relying on the body’s microbiome to generate them.
Given that postbiotics are the end product, should we bypass probiotics and prebiotics in favor of postbiotic supplements? The answer is a resounding no. The longer explanation relates to the existing evidence.
Postbiotics encompass a diverse range of compounds, and research on their health effects is still evolving. While some studies hint at possible benefits, the quality and relevance of this evidence can vary significantly.
Some postbiotics have reportedly been linked to improved mood and enhanced sleep quality. Other findings originate from laboratory experiments, such as the reduced invasion of colon cancer cells in cell cultures or protection against E. coli infection in tightly controlled settings. While these results are intriguing, further research is needed to directly apply them to humans.
Animal studies indicate that certain postbiotics may enhance the gut’s surface area, potentially aiding nutrient absorption. However, results observed in animals do not always carry over to humans.
About the author
Rachel Woods is a Senior Lecturer in Physiology at the University of Lincoln.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Human studies also have limited evidence. For example, butyrate—a short-chain fatty acid produced when gut bacteria metabolize fiber—has been associated with possible improvements in symptoms for those with inflammatory bowel disease.
A double-blind, placebo-controlled study observed that supplementation with a heat-killed strain of Lactobacillus pentosus reduced the incidence of colds among older adults. Another review found that a heat-killed strain of Lactobacillus acidophilus may both decrease the risk and shorten the duration of diarrhea in children.
Other postbiotics, like exopolysaccharides, have demonstrated promise in boosting immune responses in cell and animal studies. However, these results are still preliminary.
One type of postbiotic, bacterial lysates, is already utilized in medical practice. These products, made from broken-down bacteria, are prescribed in some countries to help prevent recurrent respiratory infections in vulnerable individuals. They function by stimulating the immune system. However, beyond these specific clinical applications, substantial evidence supporting the use of postbiotic supplements remains lacking.
Practical advantages but limited evidence
When discussing the advantages of postbiotics, researchers often refer to practical and technical traits rather than confirmed health benefits. Unlike probiotics, which are live organisms, postbiotics are non-living compounds. This characteristic makes them more stable, easier to store, and less susceptible to heat, oxygen, and time. Consequently, the amount listed on a supplement label is more likely to be accurate.
Postbiotics may also be safer for vulnerable populations, such as immunocompromised individuals, because they do not involve the consumption of live bacteria. These features make postbiotics appealing from both manufacturing and safety perspectives.
Nevertheless, these practical advantages do not confirm that postbiotics are more effective for health improvements. Evidence supporting their benefits in humans remains limited and is often specific to certain compounds. Furthermore, there is a lack of standardization. Postbiotics encompass a wide array of substances with varying biological effects and dose requirements, making it difficult to generalize findings across different postbiotics.
For most individuals, the best way to support the gut microbiome is through a diverse diet rich in fiber and fermented foods, fostering the natural production of postbiotics while also offering broader nutrition that supplements cannot replicate.
Perhaps most importantly, postbiotic supplements cannot replace the holistic benefits of whole foods. For instance, consuming live yogurt not only provides probiotics but also calcium and protein. Pairing yogurt with a banana supplies prebiotic fiber, along with potassium and vitamin B6, enabling the gut to generate postbiotics naturally while delivering a wide range of nutrients simultaneously.
Cost is another factor to consider. Supplements can be pricey, and for many, allocating that budget toward a varied diet rich in fiber and fermented products is likely to yield greater health benefits overall.
So, what is the current standing of postbiotics? They present an exciting field of research and may become useful in clinical scenarios or for specific vulnerable groups. However, the evidence does not support a shift away from probiotics and prebiotics in favor of postbiotic supplements for the general population.
At this time, the most effective way to benefit from postbiotics is to allow your gut to function as it evolved. Consuming a diet that includes both probiotic foods and prebiotic fibers enables gut bacteria to produce postbiotics naturally. Until research on postbiotic supplements strengthens, focusing on whole foods remains the most practical and evidence-based strategy.
