Microbiome: Purposeful Factory Farming

10. May 2016
Share article

Researchers trace asthma, type 1 diabetes and allergies back to genetic risk and environmental causal factors. Many studies show how important the intestinal microbiome is in this context. Instead of ending up receiving delayed treatment, it's worth protecting our bacterial dwellers from the cradle to the grave.

It’s a living community of a special sort: in our intestines there are, scientists calculate, ten to a hundred trillion bacteria bustling about. The MetaHIT-project (Metaenomics of the Human Intestinal Tract) shows more than 1.000 various species to be found, carrying 3,3 million genes. It’s becoming ever clearer what kind of significance the microbiome actually has. Here is an overview.

Diabetes dammed off

Ramnik J. Xavier, Cambridge, found out that the microbiome of infants changes well before type-1-diabetes develops. Together with colleagues, he recruited as part of the DIABIMMUNE-Study 33 small children from Finnland und Estland, in order to explain regional differences. All subjects carried risk factors for type-1 diabetes.

About twelve months before the autoimmune disease expressed itself, alpha diversity dropped by 25 percent. Scientists interpret this to be a statistical measure for species diversity in tightly confined regions. Bacteria with presumably protective effects disappear – to the advantage of other bacteria which Xavier labels as “potentially dangerous”. Their increase in number leads to inflammations. The metabolome, that is to say the comprehensive metabolism of all bacteria, does not change as an outcome of this. The researchers do not only see potential usefulness in stool analyses. They write that it might also be possible for risk patients to profit from stool transplants, in order to avert falling victim to type-1 diabetes. At present doctors are most prominently employing this procedure with Clostridium difficile-associated diarrhoea.

The alternative: if children receive probiotics during the first 27 days of life, their risk of developing islet autobodies is statistically significantly reduced. This is what Ulla Uusitalo, Tampa, working together with colleagues at the TEDDY-Consortium (The Environmental Determinants of Diabetes in the Young) found out.

Intestines protect the lungs

Our very little patients do not only suffer from metabolism-based diseases. Atopies turn up a great deal more frequently. Marie-Claire Arrieta from Vancouver examined the stool probes of 319 infants. She followed the health development of her very young subjects over three years. Children who later suffered from asthma are lacking FLVR bacteria – to be precise Faecalibacterium, Lachnospira, Veillonella and Rothia. In the reverse hypothesis Arrieta wanted to know whether these microorganisms have protective properties.

When Arrieta transferred stools from asthma-threatened children to the intestine of sterile, newborn mice, the following effects were seen: whenever researchers stimulated the airways, inflammation reactions appeared. When the animals however received FLVR bacteria, asthma-like symptoms were absent. This difference might derive from the metabolic production of short chain fatty acids, speculate the authors. They suggest further studies, in order to evaluate the significance of various germs.

Small molecules with bite

Short chain fatty acids also play a role in moderating the strong graft-versus-host-reactions after allogenic stem cell transplantations. Nathan D. Mathewson from Ann Arbor, Michigan wanted first and foremost to prevent severe intestinal damage. When he provided either butyrate or bacteria which produce butyrate to mice following a stem cell transplantation via stomach probe, there was a distinctly reduced level of undesirable side reactions. Mathewson sees two mechanisms which account for his observations: on the one hand the molecule works as an energy source for epithelial cells. On the other hand it inhibits histone-deacetylases. These enzymes not only regulate transcription processes – they also control the cell cycle including the death of the intestinal epithelium cells. After his success with rodents Mathewson now plans clinical studies. He wants to attempt to “feed” butyrate-producing bacteria in the human intestine with starch derivatives which we cannot break down.

Sometimes good, sometimes not so good

Intestinal bacteria not only have – as can be deduced from the mentioned studies – desired effects, but can lead to aggravation of the particular illnesses. The background to this is as follows: shortly after birth, bacteria settle in our intestine, and a certain tolerance develops by way of regulatory T-cells. These species, according to earlier studies, also play a central role in stroke episodes. In the case of transgenic mice whose immune systems carry no regulator T-helper cells, the extent of damage falls by 75 percent in comparison with wild type.

Corinne Benakis from New York is now pursing the question of whether pharmacological interventions are possible – and came to a differentiated point of view. She treated rodents for two weeks using amoxicillin and clavulanic acid. Subsequently Benakis simulated a stroke attack by blocking cranial arteries. The extent of damage effectively dropped by 60 percent in comparison with the control group. The researchers after giving the antibiotic doses found more regulatory T-cells in the intestine. At the same time there were fewer gamma-delta T-cells, a type which, according to Benakis, even reaches the soft tissue in the meninges. Clinical relevance here is still not clear. Looked at purely in speculative terms, people with high risk of stroke could potentially profit from an antibiotic prophylactic.

8 rating(s) (4.88 ø)

Comments are exhausted yet.

3 comments:

Physician

Fascinating indeed and interesting that nutritionists have been advising on this subject for years

#3 |
  1
GuestAngelica Ursula Landau
GuestAngelica Ursula Landau

Very interesting.
In animals (cattle) it is given to calves.

#2 |
  1
Heilpraktikerin Elinor Robinow
Heilpraktikerin Elinor Robinow

Very interesting! Should certainly be pursued further! Would make such a big difference to so many patients! From the very young to the elderly and oldest.

#1 |
  1
Copyright © 2017 DocCheck Medical Services GmbH
Language:
Follow DocCheck: