Humans aren’t just human; there are about as many bacterial cells in our bodies as human cells.1 In fact, humans evolved from the combination of multiple bacterial cells that combined to form eukaryotic cells: cells with distinct parts called organelles that perform different functions. Similarly, each type of microbe in our body serves a function in our microbiome.2 This follows that microbes and organelles alike have incredible impacts on human health, including fatigue and energy levels.
Mitochondria are organelles suspected to have evolved from alphaproteobacteria, and they produce the energy by which our bodies operate.2 Amazingly, hundreds to thousands of these bacterial artifacts are found inside each of our cells.3 One biohack to optimize energy levels is to increase the number of mitochondria our cells have, and a simple way to do this is to exercise. Over time, our bodies adapt to the increased energy needs by producing more mitochondria for each cell, thus increasing our energy output potential.3
The microbiome also plays a major role in maintaining energy levels. The human body simply doesn’t have the metabolism to digest certain complex carbs and proteins. There are about 25,000 human genes compared to millions of unique bacterial genes in the microbiome; therefore, the microbiome has much greater metabolic flexibility.3 The undigested carbohydrates that enter our colon are then fermented by microbes into one of many compounds. One such compound, short-chain fatty acids (SCFAs), represent 6-10% of the energy source ultimately used by our bodies.4 Therefore, 6-10% of our energy is attributed directly to the microbiome; that could mean the difference between your desire to go for a run
However, SCFAs produced by the microbiome play an even larger role when it comes to regulating energy levels. SCFAs promote slower movement of food through the gut, thereby giving more time to absorb all the nutrients for energy.4 SCFAs also stimulate leptin signals to the brain, thereby suppressing appetite and regulating energy balance.4 Furthermore, SCFAs protect against oxidative damage by stimulating stress response genes and by acting as antioxidants, thus enhancing mitochondrial function and fighting fatigue.3 Lastly, some SCFAs lead to increased insulin sensitivity, which is closely tied to energy levels and proper nutrient absorption.3 In these ways, microbes are the producers of signals to your brain that tell you if you are hungry, full, energized, or tired.
How can we biohack increased SCFA production in our colon? As it turns out, the limiting factor of SCFA production is most oftentimes dietary fiber. As a biohacker, you can feed your microbiome via increased fiber intake, thus enriching your microbiome’s SCFA production and enhancing your energy levels.3,4
The ASM editorial is organized by the Juniata College Chapter of the American Society for Microbiology.
Sender R, et. al. bioRxiv. January 2016:036103. doi:10.1101/036103
Gray MW,et. al. Science (80- ). 1999;283(5407):1476-1481. doi:10.1101/cshperspect.a011403
Clark A, et al. Front Physiol. 2017;8:319. doi:10.3389/fphys.2017.00319
Krajmalnik-Brown R, et. al. Nutr Clin Pract. 2012;27(2):201-214. doi:10.1177/0884533611436116