In the largest study of its kind ... microbes 900 microorganisms under a microscope

Tariq Kabil

A microbiome is the group of microbes that coexist peacefully on the body or inside the intestine of any living organism. These organisms participate with the host in the metabolism process and directly affect it.

And for good reason, humans have begun to pay more attention to the bacteria that live in our guts, because microbes help digestion and disease, and play a pivotal role in the well-being of many organisms, from rodents to primates.

For the first time, scientists have been able to compare the microbiome of 900 species of mammals, birds, reptiles and amphibians, and comparative analysis of microbiome revealed that bats are more similar to birds compared to other mammals.

Details of the study were published on January 7 in the journal "M Bio", and it became clear to researchers that birds and bats have a strange microbiome similarly, and neither of them appears to be very dependent on them.

The first of its kind
To find out the relationship between gut microbiology in these different species, Holly Lutz, a research associate at the Chicago Museum, and a postdoctoral researcher at the University of California, San Diego, and her colleagues analyzed fecal samples for 900 species of vertebrate animals, the first study of its kind to analyze microbial diversity. For both mammals and birds on a global scale.

It was a great collaborative effort that brought together researchers, zoological directors, and curators of museums from all over the world, and Lutz ventured over rock walls into remote and dark Ugandan and Kenyan caves to collect samples of African bats.

Once all the samples have been collected, scientists have used the high-throughput genetic sequence to treat them. The DNA was extracted, and then scientists were able to target a specific gene to determine the genetic fingerprint of the bacterial communities present within each sample, and they were able to make comparisons that formed the basis of the study.

An unexpected surprise
Scientists expected to see microorganisms lined up according to the family trees of the host animals. In general, in the field of microbiome research, nearby animals in the tree of strains of evolution have a similar microbiome in the intestine, as they evolved together, a pattern that scientists have referred to as the coexistence of the species.

That is why they were surprised to see that the microorganisms in the bowel of the bats did not have much in common with their mammalian relatives, as the microorganisms in the gut of the bats looked more like birds than any other group.

Scientists have found that the link between birds and bats is not in the presence of a common ancestor, but in their lifestyles, where birds and bats differ greatly, but they have developed the ability to fly independently.

This study shows that the evolutionary requirements of aviation may have a direct impact on the gut microbiome, and that some types of evolutionary adaptation - such as aviation - may lead to radically different microbial groups.

In addition to the presence of shorter viscera and fewer bacteria, the bacteria that birds and bats possess tends to vary greatly, and all types of individual bacteria are scattered almost randomly.

Quantum leap
"This research indicates that mammals - including humans - may be the exception rather than the rule in terms of their deep dependence on intestinal microbes," said Si Jin Song, co-first co-author, director of research at the University of California, San Diego's Microbiome Innovation Center. "This represents a paradigm shift in the way we think about animals and the relationships they have with microbes."

Scientists hope to learn more about the nuances of the microbiome of other animals, more about ourselves than we humans.

"If we ever find ourselves in an extreme situation in which our microbiome malfunctions, there is something we can learn from animals that do not need their microbiomes to the same extent," says Lutz.