Introduction
Just like a tropical rainforest
Our gut microbiota consists of a complex ecosystem just like a tropical rainforest, where many different species live in symbiosis.
Our microbiota contains not only hundreds to thousand distinct bacterial species, but also microbial eukaryotes, viruses, phages, and a limited number of Archaea
[1]. The human gut microbiota is of great importance in both health and disease.
Our knowledge about the microbiota has rapidly increased in the past decades (History).
We know that the microbiota has a great impact on its host, for example, it provides
a competitive barrier against invading pathogens, it utilises undigested food components,
produces essential metabolites, modulates immune responses and stimulates
intestinal maturation [2].
The microbiota does not only have positive effects on the host. When a kind of species overgrows the other microorganisms in the gut, it can cause disease due to the disturbance in balance between the different species. In this case the gut microbiota has a different composition than in most people. This disbalance is called dysbiosis. During early life the microbiota is trying to find a balance and in this period it is vulnerable to change. After birth the microbial composition is dominated by bifidobacteria. There are some specific situations which are known to have a great impact on the composition of the microbiota in children [4]. For example, mode of delivery [5] and breast- or formula feeding [6] are of influence. The microbiome normally reaches its adult form around the age of three and is than dominated by the phyla Bacteriodetes and Firmicutes [4]. In adulthood the microbiota is more stable than it is in early life [7].
It is the job of the host
immune system to avoid overgrowth and translocation of bacteria into the
subepithelial tissue [3]. Alterations in composition and function of the microbiota have been associated with many diseases like metabolic disease, immune-related diseases (inflammatory bowel disease, allergies)
and even mental disorders. The prevalence of these non-communicable diseases
(NCD) has increased in the last decades and it only increases more, especially
in the western countries [3]. One reason for this paired alteration of
microbiota and increased NCD's is thought to be due to the hygiene hypothesis.
In writing this blog we explored the
boundaries of science and published research.
Inge and Mirre will enrich your knowledge about the
role of the microbiome on gut related diseases (IBD and Clostridium difficile),
if you're more interested about the role of the microbiome in neurodegenerative
diseases, you have to read the articles of Jip and Jodie, who will discuss the
diseases Parkinson and Multiple Sclerose (MS). Our one and only man Pepijn will
tell you something about how we can influence the microbiome.
We thank you for visiting our blog and hope you will enjoy it as much as we've enjoyed making it!
(PS. We have listed a few definitions to make the information on our blog more clear, when you click here you'll find them)
Written by Mirre Verstegen
Posted on 8 oct 2018
[1] Hooper, LV. Gordon, JI. Commensal host-bacterial relationships in the gut. In: Science. Science. 2001 May 11;292(5519):1115-8.
[2] Macpherson, AJ. Harris, NL. Interactions between commensal intestinal bacteria and the immune system. In: Nature reviews. Immunology. Nat Rev Immunol. 2004 Jun;4(6):478-85.
[3] Van Best, N. Hornef, MW. Savelkoul, P. Penders, J. Review on the origin of species: Factors shaping the Establishment of Infant's Gut Microbiota. In: Birth Defects Res C Embryo Today. Birth Defects Res C Embryo Today. 2015 Dec;105(4):240-51. doi: 10.1002/bdrc.21113. Epub 2015 Nov 26.
[4] Ottman N. et al. The function of our microbiota: who is out there and what do they do? Front Cell Infect Microbiol. (2012)
[5] Biasucci G. et al. Cesarean delivery may affect the early biodiversity of intestinal bacteria. J Nutr. (2008)
[6] Schwartz S. et al. A metagenomic study of diet-dependent interaction between gut microbiota and host in infants reveals differences in immune response. Genome Biol. (2012)
[7] Rajilić-Stojanović M. Development and application of the human intestinal tract chip, a phylogenetic microarray: analysis of universally conserved phylotypes in the abundant microbiota of young and elderly adults. Environ Microbiol. (2009)