Gut microbes allow turtle ants to exist on nutrient-poor diets, study reports

Avatar By Joseph Scalise | 2 years ago

Turtle ants have a unique relationship with a 46-million-year-old gut bacteria that has allowed them to abandon the offensive tendencies of their relatives, a new study published in Nature Communications reports.

This finding comes from researchers at Drexel University, who first took an interest in the insects when they discovered that ant species with nutrient-poor diets hosted special gut bacteria.

To follow up on that discovery, the team analyzed turtle ants by feeding them both urea — the main waste ingredient in urine — and antibiotics to kill the bacteria living in their digestive tract. Without the microbes, the ants could not take in enough nitrogen to survive.

Though animal waste is rich in nitrogen, most animals cannot access the nutrients without the help of bacteria. As a result, turtle ants can process waste quite effectively. That then means they do not need to compete with other species for high-quality meals.

That lack of competition is key because it allowed them to evolve without offensive traits. They do not have a strong lower mandible like other ants, and they have also have lost their ability to sting.

In this way, the ants have abandoned any offensive measures in favor of defensive ones, such as their thick armor from which they get their name.

“That armor may be possible due to the large contributions gut microbes make to their nitrogen budgets,” explained study co-author Jacob Russell, a researcher at Drexel University, according to UPI.

As the ants need the microbes to survive, they are very protective of them. The insects have a special mesh filter in their digestive tract to protect the organisms, and they use special secretions to share them with one another. Such practices have likely reinforced the relationship and helped it build up over time. 

The team hopes to follow up on their study to see what the ant-bacteria relationship can tell them about other species, including humans.

“The turtle ant system — which is relatively simple — may prove useful in helping us to model questions about our own partnerships with microbes and how important they are for human health,” added Russell, according to Science Daily.