Want to live a longer, healthy life? The answer may be found in the microbiota which reside in the body. Scientists at the Buck Institute of Aging in the United States have managed to increase the health and lifespan of Drosophila flies thanks to alterations to the gut bacteria which reside in the intestines, publishing their work in the bimonthly Journal Cell.
Metazoans, or organisms which belong in the animal kingdom, interact with commensal bacteria which reside alongside them. In animals with a gut, these bacteria are beneficial, helping out with life processes like digestion and pathogen elimination.
In this study, the relationship between these bacteria and their host, Drosophila (a genus of insect that includes species of fruit flies), was examined. Drosophila are commonly used in experiments due they reproduce easily, and in vast numbers, while being affordable to maintain. Furthermore, they may be easily manipulated to provide certain genetic traits need they be required.
Recent research has begun to unravel the connections between the composition of gut biota with diet and health, particularly in the senior population. However, the evolution from a young, healthy digestive system to which of an senior, more delicate organ system is yet to be well understood, explained lead author Dr. Heinrich Jasper, speaking to the Buck Institute website.
Looking at the Drosophila test subjects, the teams noticed the number of bacteria present in the gut increases with age. This increase may be due to the FOXO gene being continually activated as a result of aging, suppressing a class of molecules known as PGRP-SCs. These molecules are similar to ones found in humans, PGLYRPs, and have been found to control the immune system’s reaction to bacteria.
As PGRP-SCs production in the Drosophila decreases as a result of the over activation of the FOXO gene, the body responds with an altered and far from efficient immune response, and allows a proliferation of bacteria within the gut. As a result, the intestines become inflamed, which may then go on to cause a suite of other conditions.
The research looked to create a hierarchical map, so to speak, of the effects of an altering gut microbiota so they might pin point where it may be possible to help remedy a commensal bacterial imbalance which may cause the decrease in efficacy and increased fragility of the aging digestive system.
Promisingly, the researchers were particularly enthralled by the results of experiments designed to increase the expression of the immune-regulating PGRP-SC molecules in the fruit flies. When the epithelial cells, cells that line many structures throughout the body, are reprogrammed to produce the PGRP-SCs, correct microbial balance was resumed throughout the gut. The Drosophila lifespan increased as a result.
Importantly, certain drugs might mimic the increased PGRP-SC production, meaning it may be used in humans in the future, allowing a homeostatic state in the gut tissue, with cells functioning at a normal and stable rate.
Dr. Jasper seemed to be intrigued about the potential of his team’s research, saying there may be a possibility to be able to affect commensal bacterial population in order to have an effect on prolonging life and health, while concluding it may be important to maintain proper gut biota health in order to remain healthy for longer.
How might research into human biology and the immune system support better understanding at local level?