The gut microbiome -- the world of microbes that inhabit the human intestinal tract -- has captured the interest of scientists and clinicians for its critical role in health. However, parsing which of those microbes are responsible for effects on our wellbeing remains a mystery.
Taking us one step closer to solving this puzzle, researchers have developed a mathematical approach to analyze and model interactions between gut bacteria in fruit flies. This method could lead to a more sophisticated understanding of the complex interactions between human gut microbes. Their finding appear in the Proceedings of the National Academy of Sciences.
The human gut microbiome as yet is too diverse to fully analyze. Instead, the research teamused the fruit fly as a model organism to tease apart how the presence of particular gut bacteria could lead to physical and behavioral effects in the host organism.
The researchers examine the interactions between five core species of bacteria found in the fly gut, and calculate how the presence or absence of individual species influences aspects of the fly's fitness, including lifespan, fertility and development. "The classic way we think about bacterial species is in a black-and-white context as agents of disease -- either you have it or you don't," the author said. "Our work shows that isn't the case for the microbiome. The effects of a particular species depend on the context of which other species are also present."
Building on previous research that found the presence versus the absence of bacteria affected the longevity of an organism (sterile hosts lived longer), the researchers' work on this project revealed that the situation is far more nuanced. For example, the presence of certain bacteria might increase the host's fecundity, while others might decrease longevity. "As we examined the total of what we call a fly's fitness -- it's chances of surviving and creating offspring -- we found that there was a tradeoff between having a short lifespan with lots of offspring, versus having a long lifespan with few offspring," author explained. "This tradeoff was mediated by microbiome interactions."
To decipher these interactions, authors performed a combinatorial assay, rearing 32 batches of flies each inhabited by a unique combination of the five bacteria. For each bacterial combination, Ludington measured the fly's development, fecundity and longevity. The analysis of the interactions required authors to develop new mathematical approaches.
"One model that often would be a starting point would be to consider the interactions between pairs of bacteria," said the senior author, whose research delves into the physics of complex systems. "This research shows us that a strictly pairwise model does not capture all of the observed fly traits."
What the study shows, the researchers said, is that the interactions between the bacterial populations are as significant to the host's overall fitness as their presence -- the microbiome's influence cannot be solely attributed to the presence or absence of individual species. "In a sense," said the author, "the microbiome's influence on the host is more than the sum of its parts."
The newly developed models could be extended to better understand the interactions of the thousands of different species of bacteria in the human microbiome, which could, in turn, shed light on the many connections to microbiome-affiliated diseases including mood disorders, neurological dysfunctions, autoimmune diseases and antibiotic-resistant superbugs.
"In many cases infections are caused by bacteria that we all have in ourselves all the time, and are kept in check by native gut bacteria," the senior author said. It's not so much that the infection is some new, horrible bacteria, \ but that the populations of other bacteria have changed, resulting in unrestricted growth for the infectious bacteria.
"It's really about understanding the population dynamics of these systems," the senior author said.
http://www.news.ucsb.edu/2018/019279/modeling-microbiome
http://www.pnas.org/content/early/2018/11/29/1809349115
http://sciencemission.com/site/index.php?page=news&type=view&id=publications%2Fmicrobiome-interactions&filter=22
Latest News
Mutations in noncoding DNA…
By newseditor
Posted 24 Apr
More influence of environme…
By newseditor
Posted 24 Apr
The assembly of the human c…
By newseditor
Posted 24 Apr
Wiring of the human neocortex
By newseditor
Posted 24 Apr
Abusive drugs hijack natura…
By newseditor
Posted 23 Apr
Other Top Stories
Bio-inspired hydrogel protects the heart from post-op adhesions
Read more
Heart health protein linked to Alzheimer's dementia
Read more
Intermittent fasting 'no magic bullet for weight loss'
Read more
Phase separation drives aberrant chromatin looping and cancer devel…
Read more
Novel lncRNA counteracts heart failure progression
Read more
Protocols
A programmable targeted pro…
By newseditor
Posted 23 Apr
MemPrep, a new technology f…
By newseditor
Posted 08 Apr
A tangible method to assess…
By newseditor
Posted 08 Apr
Stem cell-derived vessels-o…
By newseditor
Posted 06 Apr
Single-cell biclustering fo…
By newseditor
Posted 01 Apr
Publications
Massively parallel screen u…
By newseditor
Posted 24 Apr
Distinct genetic and enviro…
By newseditor
Posted 24 Apr
Hippocampus-to-amygdala pat…
By newseditor
Posted 24 Apr
Integrative spatial analysi…
By newseditor
Posted 24 Apr
Time-series reconstruction…
By newseditor
Posted 24 Apr
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar