Humans can't digest plant fiber like cows do—we don't have the right enzymes. Instead, our gut bacteria do a little bit of breaking it down, which suggests our ancestors relied more on meat than plants for energy.

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Human Digestive Physiology and Evolutionary Diet: A Metabolomic Perspective on Carnivorous and Scavenger Adaptations

Narrative Review

2025 Jul 4

Humans can't digest plant fibers like cellulose on their own, so we rely on gut bacteria to help a little—but our bodies evolved to get most energy from meat, not plants, and this study shows how our digestion changed over time to favor animal foods.

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Source Study

Human Digestive Physiology and Evolutionary Diet: A Metabolomic Perspective on Carnivorous and Scavenger Adaptations

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DOI: 10.3390/metabo15070453

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71%