How the microbiome challenges our concept of self

Tobias Rees (professor of anthropology at McGill University and director at Berggruen Institute in Los Angeles), Angela Douglas (professor of molecular biology and genetics at Cornell University), and Thomas Bosch have formulated in a joint essay, published February 22 2018 in PLOS Biology, on why the metaorganism concept demands a redefinition of the traditional concepts of the self.

How the microbiome challenges our concept of self.

See also the March 7th 2018 Motherboard article by Rebecca Flowers:
Our Microbiomes Are Making Scientists Question What it Means to Be Human.
Are we people or a “megaorganism?”

The Bosch lab uncovers links between microbiome and essential tissue contractions for healthy bowel function

The contractions of the body are triggered by nerve cells (in green); Bacteria (in red) intervene in the regulatory mechanism of the pacemaker cells underlying this process.
Figure: Christoph Giez, dr. Alexander Klimovich

Spontaneous contractions of the digestive tract play an important role in the vast majority of organisms in order to ensure a healthy intestinal function. From simple invertebrates to humans, there are consistently similar movement patterns that transport and mix the contents of the intestine through the rhythmic contraction of the muscles. These contractions of the intestine are indispensable for the digestive process and are referred to in science as peristalsis. In various diseases of the digestive tract, for example, serious inflammatory bowel disease in humans, there are disorders of natural peristalsis. So far, little is explored by which factors these contractions are controlled.

Ph.D. student Andrea Murillo together with postdoc Alexander Klimovich and other members of the Bosch lab could prove for the first time that bacterial colonization plays an important role in peristalsis in the freshwater polyp Hydra. The observation that microorganisms within the gut can affect essential pacemaker functions in peristalsis are  published in the journal “Scientific Reports”.


ReviewRees T, TCG Bosch, AE Douglas (2018) How the Microbiome Challenges our Concept of Self. PLoS Biol. 16(2):e2005358 pdficon

ReviewBang, C, Dagan T, Deines P, Dubilier N, Duschl WJ, Fraune S, Hentschel U, Hirt H, Hülter N, Lachnit T, Picazo D, Pita L, Pogoreutz C, Radecker N, Saad MM, Schmitz RA, Schulenburg H, Voolstra CR, Weiland-Brauer N, Ziegler M, Bosch TCG (2018). Metaorganisms in extreme environments: do microbes play a role in organismal adaptation? Zoology, published February 15, 2018.

paperWein T, Dagan T, Fraune S, TCG Bosch, Burkhard T, Reusch H, NF Hülter (2018) Carrying capacity and colonization dynamics of the Hydra host habitat. Front. Microbiol, in press

paperMortzfeld BM, Taubenheim J, Fraune S, Klimovich AV, Bosch TCG (2018). Stem cell transcription factor FoxO controls microbiome resilience in Hydra. Front Microbiol., in press

Night at the museum:

Composer Ralph Vaughan Williams meets his great uncle Charles Darwin!




Friday, November 10 2017:
In the second night concert of the Zoological Museum the string quartet of the Kiel Philharmonic Orchestra performed pieces of Ralph Vaughan Williams who was related to Charles Darwin (Ralph’s great-uncle). The music was accompanied by a reading from Charles Darwin´s letters by Thomas Bosch.





„…Und wenn ich mein Leben noch einmal zu leben hätte, dann würde ich es mir zur Regel machen, mindestens einmal in der Woche ein wenig Lyrik zu lesen und etwas Musik zu hören;
vielleicht wären die jetzt verkümmerten Teile meines Gehirns dann, durch den ständigen Gebrauch, aktiv geblieben. Der Verlust dieser Empfänglichkeit ist ein Verlust an Glück und mag wohl dem Intellekt Schaden zufügen, noch wahrscheinlicher aber dem moralischen Charakter, weil ein solcher Verlust den emotionalen Teil unserer Natur verkümmern lässt.“

– Charles Darwin, aufgezeichnet im Mai und August 1876, (Aus „Mein Leben“)

Nerves control the body’s bacterial community

The Bosch lab proves, that there is close cooperation between the nervous system and the microbial population of the body

Nerve cells

Nerve cells (in green) of the freshwater polyp Hydra produce antimicrobial peptides and thus shape the animal’s microbiome. Rod-shaped bacteria can be seen at the base of the tentacles, marked in red. Image: Christoph Giez, Dr. Alexander Klimovich

A central aspect of life sciences is to explore the symbiotic cohabitation of animals, plants and humans with their specific bacterial communities. Scientists refer to the full set of microorganisms living on and inside a host organism as the microbiome. Over the past years, evidence has accumulated that the composition and balance of this microbiome contributes to the organism’s health. For instance, alterations in the composition of the bacterial community are implicated in the origin of various so-called environmental diseases. However, it is still largely unknown just how the cooperation between organism and bacteria works at the molecular level and how the microbiome and body exactly act as a functional unit. An important breakthrough in deciphering these highly complex relationships has now been achieved by the Bosch lab. Using the freshwater polyp Hydra as a model organism, the Kiel-based researchers and their international colleagues investigated how the simple nervous system of these animals interacts with the microbiome. They were able to demonstrate, for the first time, that small molecules secreted by nerve cells help to regulate the composition and colonisation of specific types of beneficial bacteria along the Hydra’s body column. The scientists published their new findings in Nature Communications this Tuesday September 26 2017


Fibres of intestinal tissue (in red) surround the nerve cells (in green) of the freshwater polyp Hydra. Image: Christoph Giez, Dr. Alexander Klimovich

Original publication:
René Augustin, Katja Schröder, Andrea P. Murillo Rincón, Sebastian Fraune, Friederike Anton-Erxleben, Ava-Maria Herbst, Jörg Wittlieb, Martin Schwentner, Joachim Grötzinger, Trudy M. Wassenaar, Thomas C.G. Bosch (2017): “A secreted antibacterial neuropeptide shapes the microbiome of Hydra”. Nature Communications, Published on September 26, 2017, doi:10.1038/s41467-017-00625-1