What is a Postbiotic?
In recent times, we've been unraveling a crucial part of what happens in our gut. This new understanding is fascinating because it has a significant impact on various aspects of our health. Some of these aspects, which we previously didn't associate with our gut, include our mood, brain function, immune system, physical performance, and skin health, among others. In this article, we'll delve into the topic of butyrate , a short-chain fatty acid generated from the fermentation of fiber present in our diet, specifically in the lower digestive tract. For this reason, it's considered a postbiotic, since it's produced by certain saprophytic bacteria that depend on the fiber we consume and that should inhabit our terminal ileum and colon.
These butyrate-producing bacteria are essential for maintaining our gut health and, consequently, our overall health. The compound produced by these bacteria in our gut, the postbiotic known as butyrate, plays a crucial role in multiple aspects of our physiology.
The gut microbiome and butyrate
The gut microbiome, residing in our intestines, is a complex universe of trillions of bacteria, viruses, archaea, phages, and fungi that work in harmony to break down food , produce vitamins, amino acids, and fatty acids, and regulate our immune system, thus protecting us from pathogens. Given the importance of our gut health, this field has experienced a surge in research in recent decades.
Butyrate , as mentioned, is a short-chain fatty acid produced from the fermentation of dietary fiber in the gastrointestinal tract. In addition to being a crucial energy source for colon cells, butyrate improves energy expenditure, insulin sensitivity, and strengthens the intestinal barrier, thus helping to protect against gut dysbiosis.
So, where can we find butyrate? While it's not found directly in food, consuming certain types of fiber provides our gut bacteria with the materials they need to produce it. Some foods rich in these fibers include resistant starch, inulin, pectin, fructooligosaccharides, and arabinoxylan, which are found in a variety of fruits, vegetables, and whole grains.
Despite the availability of these foods, many people still have low butyrate levels due to insufficient intake of dietary fiber. In such cases, butyrate supplementation may be essential to restore gut balance and promote overall health.
Determining whether we have low levels of butyrate generally requires a stool test , although certain symptoms such as gastrointestinal problems, mood changes, and reduced insulin sensitivity may indicate a deficiency.
To increase butyrate levels , a high-fiber diet is essential, but when this isn't possible, butyrate supplements can be an option. However, not all supplements are created equal, so it's important to choose those containing bioavailable forms of butyrate.
If you're looking to increase butyrate levels in your colon, consider adding these foods to your diet:
- Apples
- Onions
- Asparagus
- Broccoli
- Brussels sprouts
- Cauliflower
- Leafy green vegetables
- Whole grains such as oats soaked in cold water for 8-12 hours for a breakfast that encourages butyrate production by bacteria.
- Unripe (greenish) bananas
- Chilled brown rice
- Plantain or cassava flour
In summary, butyrate plays a crucial role in gut and overall health. Through a balanced diet and, in some cases, appropriate supplementation, we can ensure optimal levels of this important compound to promote our well-being.
References:
- Gao Z, Yin J, Zhang J, et al. Butyrate improves insulin sensitivity and increases energy expenditure in mice . Diabetes. 2009; 58 (7): 1509-17.
- Peng L, Li ZR, Green RS, Holzman IR, Lin J. Butyrate improves the intestinal barrier by facilitating tight junction assembly through activation of AMP-activated protein kinase in Caco-2 cell monolayers . J Nutr. 2009; 139 (9): 1619-25.
- den Besten G, van Eunen K, Groen AK, Venema K, Reijngoud DJ, Bakker BM. The role of short-chain fatty acids in the interaction between diet, gut microbiota and host energy metabolism . J Lipid Res. 2013; 54 (9): 2325-40.
- Bourassa MW, Alim I, Bultman SJ, Ratan RR. Butyrate, neuroepigenetics, and the gut microbiome: Can a high-fiber diet improve brain health?. Neurosci Lett. 2016; 625: 56-63. doi:10.1016/j.neulet.2016.02.009