Scientists studied the tiny bacteria living inside 239 ants from 36 different species in the Indo-Pacific region to understand what shapes these bacterial communities. They discovered that what an ant eats—whether it’s meat, plants, or both—is the biggest factor determining which bacteria live in its gut. Ants that eat meat and insects have more diverse and complex bacterial communities, while ants that only eat plants have simpler bacterial communities. This research helps us understand how bacteria and insects evolve together and adapt to different lifestyles in tropical forests.

The Quick Take

  • What they studied: How the bacteria living inside ants’ bodies differ based on what the ants eat and where they live
  • Who participated: 239 ants representing 36 different species from 24 different ant groups living in Indo-Pacific tropical forests, ranging from ground-dwelling hunters to tree-living plant-eaters
  • Key finding: An ant’s diet is the main factor that determines which bacteria live in its body, not where it builds its nest. Meat-eating ants have more types of bacteria, while plant-eating ants have fewer types but different kinds
  • What it means for you: This research helps scientists understand how bacteria and insects work together to survive. While this study focuses on ants, it suggests that diet plays a major role in shaping the bacteria that live in many animals’ bodies, which could eventually help us understand human health better

The Research Details

Researchers collected 239 ants from the Indo-Pacific region representing different lifestyles—some lived on the ground hunting other insects, some lived in trees eating plants, and some ate a mix of both. They used advanced DNA testing to identify all the bacteria living inside each ant’s body. They also measured something called stable isotopes (a type of chemical fingerprint) in the ants’ bodies to determine what each ant species ate. This combination of methods allowed them to see which bacteria were connected to different diets.

The scientists then used special computer programs to compare the bacterial communities across all the ants. They looked at how many different types of bacteria each ant had and which specific bacteria were most common. Finally, they used evolutionary analysis to understand how these bacterial partnerships might have changed as ants evolved different eating habits over millions of years.

This research approach is important because it combines multiple types of information—DNA analysis, chemical signatures, and evolutionary history—to answer a complex question. By studying ants from a region that hasn’t been well-researched before (Indo-Pacific), the scientists could test whether patterns found in other regions hold true everywhere. This helps us understand if the relationship between diet and bacteria is a universal rule or if it varies by location.

This study is a solid research article published in a peer-reviewed scientific journal, meaning other experts reviewed it before publication. The researchers studied a large number of ants (239) from many different species (36), which makes their findings more reliable. They used advanced DNA sequencing technology and multiple analytical approaches, which strengthens their conclusions. However, this is observational research rather than an experiment where variables are controlled, so while it shows strong patterns, it cannot prove that diet directly causes the bacterial differences.

What the Results Show

The most important finding is that what an ant eats is the strongest predictor of which bacteria live in its body—much stronger than where the ant builds its nest. Ants that eat meat and insects (predators and omnivores) have significantly more diverse bacterial communities, meaning they host many different types of bacteria. In contrast, ants that eat only plants (herbivores) have simpler bacterial communities with fewer types of bacteria.

The researchers identified specific bacteria that differ between meat-eaters and plant-eaters. Meat-eating ants frequently contain bacteria from groups called Rhizobiales and Rickettsiales, while plant-eating ants tend to have bacteria dominated by a group called Enterobacterales. These bacterial differences are consistent across different ant species, suggesting that diet shapes bacterial communities in a predictable way.

When scientists looked at ant evolution, they found evidence that the acquisition of Enterobacterales bacteria is strongly linked to when ant species evolved to eat only plants. This suggests that bacteria may have actually helped ants evolve the ability to digest plants, or that plant-eating ants naturally selected for these particular bacteria because they were helpful.

The study also revealed that ants living in trees versus on the ground did not have significantly different bacterial communities, which was surprising to the researchers. This shows that where an ant lives matters less than what it eats for determining its bacterial partners. Additionally, the research found that different ant species with similar diets tend to have similar bacterial communities, even if those ant species are not closely related evolutionarily. This suggests that diet is a powerful force shaping bacterial communities across many different types of ants.

Previous research on ants from Central and South America (Neotropical ants) had shown that diet influences bacterial communities, and this new study confirms that pattern holds true in the Indo-Pacific region as well. However, the research also found some differences: in Neotropical ants, Rhizobiales bacteria were more common in plant-eating ants, but in Indo-Pacific ants, they’re more common in meat-eating ants. This suggests that the relationship between diet and specific bacteria may vary depending on the geographic region and the particular ant species involved.

This study has several important limitations. First, it is observational research, meaning scientists observed patterns but didn’t conduct controlled experiments to prove cause-and-effect relationships. Second, while 239 ants is a good sample size, they only represent a portion of the thousands of ant species in the Indo-Pacific region, so the findings may not apply to all ants everywhere. Third, the study doesn’t explain the mechanisms—we don’t know exactly how diet influences which bacteria survive in an ant’s body or whether bacteria help ants digest food. Finally, the research was conducted at a single point in time, so we don’t know if these bacterial communities change seasonally or over an ant’s lifetime.

The Bottom Line

Based on this research, scientists should continue studying how diet shapes bacterial communities in insects and other animals. While this study focuses on ants, the findings suggest that diet is a fundamental factor in determining which bacteria live in an organism’s body. This knowledge may eventually help researchers understand human health better, particularly regarding how our diet influences our gut bacteria. However, these findings apply specifically to ants and should not be directly applied to humans without further research.

This research is most relevant to biologists, ecologists, and evolutionary scientists studying insects and microbes. It’s also interesting for anyone curious about how nature works and how different organisms depend on each other. While the direct applications to human health are not yet clear, understanding ant-bacteria relationships helps us understand broader principles of how all animals interact with microbes. This research is not meant to provide health advice for people.

This is basic science research focused on understanding nature, not on developing treatments or interventions. There is no expected timeline for practical applications. However, the knowledge gained could eventually contribute to future research on how diet influences bacterial communities in humans and other animals over months to years.

Want to Apply This Research?

  • Users interested in insect biology could track observations of different ant species they encounter and note their feeding behavior (predatory, herbivorous, or omnivorous) alongside photos or location data, creating a personal biodiversity database
  • For users interested in ecology, this research suggests paying attention to what different insects eat in their local environment and observing how diet correlates with other characteristics—a practical way to engage with ecological science in daily life
  • Long-term tracking could involve documenting local ant species, their feeding habits, and nesting locations across seasons to build personal observations that align with scientific research methods

This research describes bacterial communities in ants and does not provide medical advice for humans. The findings are specific to ant biology and should not be interpreted as health recommendations. While understanding ant-microbe relationships contributes to general scientific knowledge, any applications to human health would require separate research and consultation with qualified healthcare professionals. This study is observational in nature and shows associations rather than proving direct cause-and-effect relationships.