When Microbiomes Collide: Peculiar Findings From Over 300 Human Fecal Transplants

By | 15/09/2022

When microbiomes collide

EMBL researchers used information from over 300 man faecal microbiota transplants to gain an ecological understanding of what happens when 2 gut microbiomes clash together

The foreground shows two yellow pipes representing the human gastrointestinal tract coming together, representing the confluence of donor and recipient gut ecosystems. Bacteria can be seen as green shapes inside the pipes and various kinds of interactions between them are shown symbolically as a mixing of colours.
Faecal microbiota transplantation as the confluence of a donor’s and recipient’s gut ecosystems. The various ‘pipes’ in the image represent human gastrointestinal tract and the bacteria within represent the recipient’s and donor’s microbial strain populations (by colour) that are pitched against each other. Credit: Aleksandra Krolik/EMBL

Faecal microbiota transplantation (FMT) – the transfer of lower intestinal fluids and microbes from 1 private to another – is sometimes used to care for inflammatory gut diseases, including ulcerative colitis and bacterial infections. Although a form of it was get-go recorded in 4th
century People’s republic of china, it was introduced to western medicine in the 1950s. In the last two decades, information technology has steadily gained prominence.

A team of researchers led past the Bork group at EMBL Heidelberg, forth with their collaborators in holland and Australia, has now used this unusual medical procedure to enquire a fascinating question – what happens when ii gut microbiomes mix together?

The reply could hold clues to better therapeutic strategies for gut disorders as well as a richer understanding of how microbial species behave and interact in complex natural ecosystems.

Transplanting microbes

Although clinical trials have demonstrated that FMTs tin effectively treat certain gut disorders, their mode of activeness remains unclear. Some hypothesise the gut microbiomes of donors accept beneficial properties that assist render the recipient’s gut to a healthy state. Still, this has never been systematically studied.

“The ‘super donor’ hypothesis is widely held among practitioners: it postulates that finding ‘good’ donors is essential to the clinical success of an FMT and that a good donor will work for many different patients,” said Sebastian Schmidt, one of the first authors of a new study published in
Nature Medicine.

However, using clinical and metagenomics data from over 300 FMTs, the researchers discovered that information technology’southward probably the recipient and not the donor that primarily determines the microbial mix resulting from this procedure. This builds upon a 2016 study from the Bork grouping that showed that microbial strains from a donor tin coexist with those from a recipient with metabolic syndrome.

The team developed a automobile-learning approach to dissect the factors that determine microbial dynamics after an FMT, including the presence or absence of individual microbial species. Their results show that species richness (a measure out of how various a recipient’due south gut microbiome was before transplant), as well as how different a recipient’s gut microbiome is from a donor’due south, are both major factors in determining which species will survive and thrive after a transplant.

An ecological experiment

Simone Li, another first author of this and the 2016 study, finds their results fascinating from an ecological perspective. “Beingness able to thrive and survive in an entirely new setting is no simple task, particularly in a dynamic surround such as the human gastrointestinal tract, where there are constant changes in acidity, oxygen levels, and nutrients, among others,” she said. “As we motion towards safer options of microbiome-based therapeutics, what goes in only matters as much as whether they stay long enough to deliver the intended benefits.”

By treating FMT procedures equally ecological experiments where whole microbial ecosystems are supplanted to new locations with pre-existing ecosystems, the researchers could draw important conclusions virtually which factors help determine how well or easily bacteria can ‘colonise’ in new environments.

As Peer Bork, the respective author of the study, points out, this may likewise have important practical applications. “Every bit our understanding of the ecological processes in the gut following FMT improves, nosotros may notice more than precise and more targeted links to clinical effects – for example, to displace only specific strains (due east.grand. pathogens) while minimising ‘collateral’ effects to the residual of the microbiome.”

Although the written report dealt primarily with bacteria and archaea, which together make up over 90 % of the gut microbiome, the researchers hold out hope that future studies may besides incorporate information from fungi, other eukaryotes, and viruses to obtain a more holistic view of this process.

“I hope (and am confident) that our findings will help to pattern more efficacious FMT protocols in the future. We provide information on which parameters are worth tuning (and which are not) when you aim to attune the recipient’s microbiome. On a longer term, this may likewise inform the pattern of ’next-gen’ personalised probiotic treatments,” Schmidt said.


Source article(s)

Drivers and Determinants of Strain Dynamics Post-obit Fecal Microbiota Transplantation

Schmidt T.Due south.B., Li S.S. et al.

Nature Medicine
xv Sep 2022

10.1038/s41591-022-01913-0

Tags: bork, gut, heidelberg, human microbiome, metagenomics, microbe, microbial ecosystems, microbiome, research highlight

Source: https://www.embl.org/news/science/when-microbiomes-collide/