Research Jonas Torfs

Abstract

The human vaginal microbiome is often dominated by Lactobacillus, which protects the female host against invading pathogens by creating an acidic environment. Interestingly, this phenotype seems to be unique to the human species: no other primate species shows dominance of lactic acid bacteria in the vaginal microbiome, raising questions about the evolution of this microbial ecosystem within the primate clade. A prerequisite to solve this evolutionary puzzle is an understanding of the microbial sources of the vaginal microbiome within primates: since all primates are born sterile, commensal bacteria have to be acquired from the environment in the broadest sense. While research often focuses on between-individual transmission (vertical from mother to daughter or horizontal between social partners), there might also be a considerable influence of other microbiomes such as the gut microbiome. In primates, the gut and vaginal niche show close anatomical proximity, facilitating a dispersal route called the 'gut-vagina axis'. Bacterial genera often overlap between the gut and the vagina in humans and primates, but this taxonomical level does not provide evidence for actual transmission as bacterial species or strains might not overlap. In this BOF SRG, we aim to test whether the gut microbiome forms an ecologically relevant reservoir of vaginal bacterial strains, using human's evolutionary closest living relative, the bonobo (Pan paniscus), as a study system. As such, the study complements a larger project investigating how vertical and horizontal transmission shapes the bonobo vaginal microbiome. We will perform deep shotgun metagenomic sequencing on fecal samples collected from female zoo-housed bonobos and integrate these data with matching vaginal swabs from these same individuals. By employing a longitudinal sampling approach, we will be able to assess whether gut and vaginal strains are detected at the same time or with a time-lag (for example, first in the gut and only later in the vagina and not in the gut anymore), and we will investigate whether transmitted strains are able to persist in the vaginal microbiome over a 10-week period, assessing their colonization potential within the vagina. The contribution of this funding will provide a more robust understanding of the sources of the vaginal microbiome within primates, yielding novel insights into the ecology and evolution of complex host-microbiome relationships within great apes, including humans.

Researcher(s)

• Promoter: Torfs Jonas

Research team(s)

• Laboratory of Applied Microbiology and Biotechnology (LAMB)

Project type(s)

• Research Project

Abstract

The human vaginal microbiome is often dominated by Lactobacillus, which protects the female host against invading pathogens by creating an acidic environment through the production of lactic acid. Interestingly, this phenotype seems to be unique to the human species: no other primate species shows Lactobacillus dominance in the vaginal microbiome, raising questions about the evolution of this microbial ecosystem within the primate clade. A prerequisite to solve this evolutionary puzzle is an understanding of the ecological processes (e.g. dispersal, local selection) shaping the primate vaginal microbiome but such knowledge is currently lacking. Here, I will investigate the vaginal microbiome of the bonobo (Pan paniscus), a species in which females show frequent sociosexual contact with other females. By performing shotgun metagenomic sequencing of vaginal swab samples and linking results to (behavioral) data in a multi-zoo bonobo cohort, I will investigate the independent effects of horizontal, vertical, and within-individual (gut-vagina) bacterial transmission on the vaginal microbiome. Moreover, I will compare human vaginal microbiome composition with that of bonobos and examine which local selection mechanisms are responsible for creating observed differences using in-vitro assays. Together, these analyses will yield new insights into the determinants, and ultimately the evolution, of this understudied microbial ecosystem.

Researcher(s)

• Promoter: Lebeer Sarah
• Co-promoter: Staes Nicky
• Co-promoter: Wittouck Stijn
• Fellow: Torfs Jonas

Research team(s)

• Laboratory of Applied Microbiology and Biotechnology (LAMB)

Project type(s)

• Research Project

Abstract

It has been known for a relatively long time that the microbes living in our gut play an important role in regulating our physical and mental health. However, recent literature emphasizes the potentially major role of the gut microbiome in the regulation of brain function and behavior. Gut microbes play an important role in the development and regulation of behavior and cognition, giving rise to a connection between the brain and the gut, also known as the gut-brain axis. Conversely, the social behavior of the host itself will directly influence the composition of the gut microbiome, indicating the axis is bidirectional. To date, very little is known about the gut-brain axis in animals, especially in non-human primates. Great apes are of particular interest, since they form an excellent study system to investigate the evolution of the gut-brain axis in humans because of their high evolutionary relatedness. Bonobos in particular form an interesting model-species due to their high overlap in socio-cognitive skills with humans, but surprisingly, their gut microbiome remains largely unstudied. Therefore, the aim of this study is to characterize the bonobo gut microbiome and to investigate which factors drive interindividual variation in gut microbiome composition and diversity, including behavior. Moreover, I will perform behavioral observations combined with experimental microbiome manipulations to closely examine the impact and dependence of the microbiome on bonobo sociality.

Researcher(s)

• Promoter: Eens Marcel
• Co-promoter: Staes Nicky
• Fellow: Torfs Jonas

Research team(s)

• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project