Doctoral defence: Kreete Lüll “Investigating the relationships between human microbiome, host factors and female health“

On 13 May at 14:15 Kreete Lüll will defend her doctoral thesis “Investigating the relationships between human microbiome, host factors and female health”.

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Supervisor:
Associate Professor Elin Org, University of Tartu

Opponent:
Dr Anne Salonen, University of Helsinki (Finland)

Summary
The human microbiome is one of the most important scientific discoveries in human healthcare in recent decades. Microbiome influences our metabolism, immune system as well as nervous system. Meanwhile, microbiome itself is affected by various factors including diet, medication, and physical activity. It has become a widely known knowledge that human phenotype and different disease states are dependent on our genetics. However, association between human genetics and microbiome are less studied.

An international consortium MiBioGen with data from more than 18,000 individuals was formed with the aim to study the effect of host genetics on gut microbiome composition. We identified 31 associations between genetic loci and microbiome as well as confirmed an association between a gene responsible for lactase production (LCT) and Bifidobacterium – an association seen in previous publications as well as replicated in new research studies.

In addition, our work searched for links between female health and microbiome. Namely, we focused on one of the most prevalent female endocrine and metabolic disorders called polycystic ovary syndrome (PCOS) and additionally investigated the microbial composition of the endometrium. Our work with PCOS and gut microbiome revealed that the effects of microbiome on PCOS work through metabolic processes and prediabetic women with PCOS diagnosis have lower bacterial diversity compared to their healthy counterparts.

Finally, we show that the genus Lactobacillus has an enormous impact on the composition of endometrial microbiome and could potentially be used as a biomarker in clinical work to help identify possible causes behind infertility problems. In conclusion, with our work we contribute to the microbiome research field by bringing new knowledge into the interplay between microbiome and genetics as well as female health that in the future would provide an impetus for further in-depth research to fully understand the role of microbiome in human health and disease.