How your gut bugs feed you (a little)
Quantifying the varying harvest of fermentation products from the human gut microbiota
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Microbiome composition barely affects total energy harvest from fermentation.
Popular science often claims that having the 'right' gut bacteria is key to health and metabolism. This study shows that while bacterial types change the *mix* of fermentation products, they don’t change the *total amount* produced.
Practical Takeaways
Increase your intake of complex carbohydrates like whole grains, legumes, and vegetables to boost microbial energy production and support gut health.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Microbiome composition barely affects total energy harvest from fermentation.
Popular science often claims that having the 'right' gut bacteria is key to health and metabolism. This study shows that while bacterial types change the *mix* of fermentation products, they don’t change the *total amount* produced.
Practical Takeaways
Increase your intake of complex carbohydrates like whole grains, legumes, and vegetables to boost microbial energy production and support gut health.
Publication
Journal
Cell
Year
2025
Authors
M. Arnoldini, Richa Sharma, Claudia Moresi, Grifin Chure, Julien Chabbey, E. Slack, Jonas Cremer
Related Content
Claims (5)
The gut bacteria in people eating lots of fiber can provide up to 12% of their daily energy, while those on a typical Western diet get only 2%–5% from their gut bugs — so what you eat changes how much energy you get from your microbiome.
What you eat—especially fiber and complex carbs—mostly decides how much gut fermentation happens, and eating more of these carbs can boost fermentation by up to five times compared to a standard Western diet. The types of gut bacteria you have don’t really change the overall amount.
Most of the stuff your gut bacteria eat turns into helpful chemicals like butyrate, and your body soaks up almost all of it—very little ends up in poop.
Your gut bacteria don’t change how much waste they produce overall, but they do change what kinds of waste chemicals—like butyrate and lactate—are made, and this mix is different for everyone depending on their unique gut bug lineup.
People can't break down tough plant fiber like cows or rabbits can, so we get almost no energy from it — their stomachs are built for that job, but ours aren't.