Your gut bacteria produce plant hormones called cytokinins that circulate through your bloodstream, according to a 2026 research study published in Gut Microbes. Scientists found that diet and gut bacteria are major sources of these compounds in mammals—when animals stopped eating, their cytokinin levels dropped significantly, and mice without any bacteria had substantially lower levels than normal mice. While researchers haven’t yet determined what cytokinins do in human bodies, this discovery reveals another way your microbiome influences your body chemistry.
Scientists discovered something surprising: your body contains plant hormones called cytokinins, and they’re not just coming from the food you eat. According to Gram Research analysis, a 2026 study found that your gut bacteria actually produce these compounds, which then circulate through your bloodstream. Researchers studied five different animal species and found cytokinins in their blood, tissues, and waste. When animals stopped eating, their cytokinin levels dropped dramatically. Even more interesting, mice without any gut bacteria had much lower cytokinin levels than normal mice. This discovery opens new questions about what these plant hormones might be doing in your body and how your diet and microbiome work together to create them.
Key Statistics
A 2026 research study of five animal species found that cytokinins—plant hormones traditionally known only in plants—are consistently present in mammalian blood and tissues, with concentrations varying by species.
According to a 2026 study in Gut Microbes, starvation significantly reduced cytokinin abundance in serum, colon, feces, and urine, confirming that diet is a major contributor to the mammalian cytokinin pool.
Germ-free mice (raised without any bacteria) showed substantially lower cytokinin levels than conventionally raised mice, establishing that gut bacteria make a significant contribution to these plant hormones in the body.
A 2026 analysis of gut microbiomes identified cytokinin-related genes across multiple bacterial taxa, with the highest representation in human microbiomes, followed by mouse and pig microbiomes.
The Quick Take
- What they studied: Whether plant hormones called cytokinins exist in animal bodies, where they come from, and how diet and gut bacteria affect their levels.
- Who participated: Five different animal species (including mice, humans, and pigs) were studied using blood samples, tissue samples, and fecal samples. Some mice were germ-free (raised without any bacteria) to test the bacteria’s role.
- Key finding: Cytokinins are present in mammalian blood and tissues, with diet and gut bacteria being major sources. Starvation significantly reduced cytokinin levels, and germ-free mice had substantially lower levels than normal mice.
- What it means for you: Your gut bacteria may be producing beneficial compounds that circulate throughout your body. This suggests that maintaining a healthy microbiome through diet could influence these hormone levels, though researchers still need to determine what these compounds actually do in humans.
The Research Details
Researchers used advanced laboratory techniques to detect and measure cytokinins in blood samples from five animal species. They analyzed the genetic makeup of gut bacteria to identify which microbes could produce cytokinins. They also performed dietary experiments where animals were starved to see how food intake affected cytokinin levels. The most revealing experiment involved comparing normal mice (with bacteria) to germ-free mice (without any bacteria), which clearly showed the bacteria’s contribution.
The team used three complementary approaches: metabolomics (measuring small molecules like cytokinins), microbiome analysis (identifying which bacteria are present), and metagenomics (reading bacterial DNA to find genes related to cytokinin production). This multi-pronged approach allowed them to connect the dots between diet, bacteria, and these mysterious compounds.
The researchers examined where cytokinins accumulated in the body by testing blood, various organs (kidney, heart, liver), the colon, feces, and urine. This comprehensive sampling revealed that cytokinins are distributed throughout the body, not just in one location.
This research approach is important because it moves beyond simply detecting cytokinins to understanding their sources. By comparing normal mice to germ-free mice, the researchers could prove that bacteria contribute to cytokinin levels rather than just guessing. The dietary manipulation experiments showed that food is a major factor, while the genetic analysis of bacteria identified which microbes might be producing these compounds.
The study’s strength lies in its use of multiple complementary techniques and multiple animal species, which increases confidence in the findings. The germ-free mouse experiments provide strong evidence for the bacteria’s role. However, the study doesn’t yet explain what cytokinins actually do in the mammalian body, which is an important limitation. The research is also preliminary in humans, with most detailed work done in mice.
What the Results Show
Cytokinins were detected in the blood of all five animal species studied, confirming these plant hormones exist in mammalian bodies. The most common form found was zeatin-O-glucoside, followed by trans-zeatin and kinetin. Importantly, the types and amounts of cytokinins varied between species—for example, mice had less trans-zeatin while humans had lower kinetin levels.
When researchers starved animals, cytokinin levels dropped significantly in blood, colon tissue, feces, and urine. This dramatic decrease proved that diet is a major source of these compounds. The researchers also found cytokinins stored in vascular tissues (blood vessels) of the kidney, heart, and liver, showing these compounds circulate throughout the body.
The genetic analysis of gut bacteria revealed that multiple types of bacteria carry genes related to cytokinin production. Human microbiomes showed the highest representation of these genes, followed by mouse and pig microbiomes. When researchers compared normal mice to germ-free mice (raised without any bacteria), the germ-free mice had substantially lower cytokinin levels, proving that bacteria contribute significantly to the body’s cytokinin pool.
The study revealed that cytokinins in mammalian blood exist at much lower concentrations than in plant tissue, suggesting mammals have evolved ways to regulate these compounds. The specific pattern of which cytokinin forms are most abundant differs from plants, indicating mammals process or select these compounds differently. The presence of cytokinins in multiple organ tissues suggests they may have biological functions beyond simply being dietary byproducts.
This is groundbreaking research because cytokinins have been known as plant hormones for decades, but their presence and role in animals has been largely ignored. Previous research focused on plants, so this systematic characterization in mammals is novel. The findings suggest that the microbiome’s role in producing bioactive compounds may be broader than previously understood, supporting growing evidence that gut bacteria influence mammalian health through multiple chemical pathways.
The study doesn’t yet explain what cytokinins actually do in mammalian bodies—their biological function remains unknown. While the research is thorough in mice, human studies are limited to blood samples, so less is known about human cytokinin distribution. The study identifies which bacteria have the genes to produce cytokinins but doesn’t prove they’re actually producing them in living animals. Finally, the research doesn’t determine whether dietary cytokinins are absorbed intact or broken down during digestion.
The Bottom Line
Maintain a diverse diet rich in plant foods, as this appears to support healthy cytokinin levels through both direct dietary intake and by feeding beneficial gut bacteria. Support your microbiome health through fiber-rich foods, fermented foods, and avoiding unnecessary antibiotics. However, these recommendations are based on preliminary evidence—researchers still need to determine whether maintaining higher cytokinin levels actually benefits human health.
Everyone should find this interesting because it reveals another way your gut bacteria influence your body chemistry. People interested in microbiome health, nutrition, and how diet affects biology should pay attention. However, until researchers determine what cytokinins actually do in humans, specific health claims cannot be made. People taking antibiotics or dealing with microbiome issues may eventually benefit from understanding this pathway.
This is early-stage research, so practical applications are likely years away. Researchers first need to determine what cytokinins do in the mammalian body before recommending specific interventions. If cytokinins prove beneficial, changes in diet or microbiome composition might show effects within weeks to months, but this remains speculative.
Frequently Asked Questions
Do plant hormones from food actually get into my bloodstream?
Research shows that cytokinins, plant hormones found in food, are detected in mammalian blood and tissues. A 2026 study found that starvation significantly reduced cytokinin levels, confirming diet contributes to these compounds in your body, though whether they’re absorbed intact or broken down during digestion remains unclear.
Can my gut bacteria make plant hormones?
Yes, according to 2026 research, gut bacteria carry genes related to cytokinin production. Germ-free mice without bacteria had substantially lower cytokinin levels than normal mice, proving bacteria contribute significantly to these plant hormones in your body.
What should I eat to support these beneficial compounds?
Eat a diverse diet rich in plant foods—vegetables, fruits, whole grains, and legumes. These foods provide both dietary cytokinins and fiber that feeds beneficial bacteria. A 2026 study found that starvation reduced cytokinin levels, suggesting consistent plant food intake supports these compounds.
Why do scientists care about plant hormones in my body?
Researchers are investigating whether cytokinins have biological functions in mammals beyond being dietary byproducts. A 2026 study found cytokinins distributed throughout organs like the kidney, heart, and liver, suggesting they may play a role in mammalian health, though their specific function remains unknown.
Does this mean I should take cytokinin supplements?
Not yet. While a 2026 study confirmed cytokinins exist in mammalian bodies and come from diet and bacteria, researchers haven’t determined what these compounds actually do in humans or whether supplementation would be beneficial. Eating diverse plant foods is the evidence-based approach.
Want to Apply This Research?
- Track daily plant food intake (servings of vegetables, fruits, whole grains) and correlate with energy levels, digestion quality, and overall wellness markers. This creates a personal data set to observe patterns between dietary diversity and how you feel.
- Increase plant food variety by trying one new plant-based food weekly. Use the app to log plant diversity (different vegetables, fruits, legumes, whole grains) rather than just total calories, since diversity supports a broader range of beneficial bacteria.
- Monitor microbiome-supporting behaviors: daily fiber intake (target 25-35g), fermented food consumption (yogurt, sauerkraut, kimchi), and antibiotic use. Track subjective wellness metrics like energy, digestion, and mood to identify personal patterns related to microbiome health.
This research is preliminary and does not yet establish that cytokinins have specific health benefits in humans. The study identifies the presence of these compounds and their sources but does not determine their biological function in mammalian bodies. Do not make dietary changes based solely on this research without consulting a healthcare provider. This article is for educational purposes and should not be considered medical advice. Anyone with digestive disorders, taking antibiotics, or considering microbiome-targeted interventions should consult with a qualified healthcare professional.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.