microbes may prove to be powerful nutritional alliesOh really! Is that possible? Were some of the reactions we received. But yes as shown by a latest research, this is true. Now, a study by scientists from the Florida campus of The Scripps Research Institute (TSRI) sheds new light on a surprising and critical role that microbes play in nutritional disorders such as protein malnutrition.

Microbes, small and ancient life forms, play a key role in maintaining life on Earth. Life is impossible without microbes. To study the basic mechanism of how these microbes help metabolism, fruit fly-Drosophila melanogaster was used, as it is simple and easy to study.

In the study, a fungal microbe isolated from field-caught fruit flies called Issatchenkia orientalis was found to promote a nutritional harvest that rescued the health and longevity of undernourished flies. To learn more about the team led by TSRI biologist William Ja, read the February 12 publication of the journal Cell Reports.

Food components such as amino acids and sugar were radioisotope labeled by the researchers to measure the transfer of nutrients from food to microbe to fly. The study showed that the microbes first harvest amino acids directly from the fly’s food sources and then transfer that protein to the fly when eaten.

Research Associate Ryuichi Yamada, who spearheaded the study in the Ja lab, explained that flies touch every surface they cross in the wilderness. As flies sit on low protein food, they deposit these microbes, which metabolize and concentrate the amino acids. When these microbes are eaten up by the flies, a much needed source of dietary protein is gained by the flies. Amino acids are a vital component of protein and form the basic building blocks of our body.

Symbiosis is a give and take relationship which is quite beneficial for flies. Due to protein-enriched microbes, the lifespan of the flies extends during periods when nutrients are scarce. In fact, the microbe is commonly found in field-trapped fruit flies, said Yamada, suggesting a natural symbiosis.

The importance of microbes in fly nutrition has often been neglected and this study will help us understand numerous phenomena of host-microbe interactions. This study showed a larger picture of the partnership that can occur between microorganisms and their hosts, in addition to providing information on the harvest of nutrition and host microbe relationships. All of this can be studied further with the help of the Drosophilia fly.

For a long time researchers sought to find the much needed microbial metabolite or species which will enhance this symbiotic relationship, but what is not being appreciated is the bulk effect on primary metabolism by microbes. This study suggests that different species of microbes could help their host in improving protein consumption. In future studies, researchers hope these microbes could be utilized to prevent or treat human protein malnutrition too.

Contributed by Dr. Rachita Narsaria, MD


Scripps Research Institute. “Microbes prevent malnutrition in fruit flies, and maybe humans, too.” ScienceDaily.ScienceDaily, 12 February 2015.