Developmental Interactions Lab

1/ Extracellular vesicles (EVs) are membrane particles released from most cell types, typically 50-200 nm in diameter. They contain proteins, nucleic acids and other cargo from the secreting cells. Gram-negative and gram-positive bacteria produce different kinds of EVs.

Talk about bacterial extracellular vesicles by @MikaelNiku at #MOVE2025. They are thought to mediate microbe-host interactions in the intestine and possibly beyond. We investigate the vesicle proteomes of the mammalian intestinal microbiota. 🧵

Presenting our research on the effects of gestational antibiotics on offspring microbiota, immune system and growth, and on bacterial extracellular vesicle proteomes at @iuis_online #IUIS2025!

Rose gave an excellent talk at the @BioCityTurku symposium "Unleashing the power of metabolism" #BCS2024!

Presenting our research at the meeting of the Finnish Society of Developmental Biology! Great event, great atmosphere.

🧵Thus: although the uterus is largely sterile, the maternal microbiota broadly modulates fetal gene activity and is likely important for the developing intestinal immune system and brain, and for pregnancy regulation. Microbial metabolites probably mediate many of these impacts.

🧵Fetal energy metabolism was also affected by the maternal microbial status (and/or the germ-free dam physiology). The most strongly downregulated gene in all the tissues from germ-free fetuses was Ide, coding for the insulin-degrading enzyme.

🧵The impacts of maternal microbiota on fetal gene expression were associated with microbially modulated metabolites: aryl sulfates, indoles & other AhR ligands, trimethylated compounds TMAO & 5-AVAB, dipeptides, fatty acid derivatives, and many currently unidentified compounds.

🧵In placenta, multiple critical genes such as prolactin were differentially expressed in germ-free and normal dams, suggesting that the maternal microbiota may be intimately involved in the regulation and maintenance of pregnancy.

🧵Also in the fetal brain, interferon and inflammatory signaling genes were less active in the fetuses of germ-free dams. Interestingly, many important genes for neural development and neuronal function were significantly differentially expressed.

🧵In the fetal intestine, genes essential for host-microbe interactions, innate immunity and epithelial barrier were largely downregulated in fetuses of germ-free dams. Thus, the maternal microbiota helps the fetus to prepare to the outside microbial world already before birth.

Developmental Interactions Lab website: helsinki.fi/en/researchgroup…

Love it when Stuff Just Works! qPCR for reindeer calf rumen microbiota: - Bacteria: bread and butter - Archaea: bull's eye! - Protozoa: in one fell swoop - Fungi: well a challenge in a day keeps boredom away

Our PhD researcher Aleksi gave a great talk at @wellcometrust conference Microbiome Interactions #MIHD22! 💪 Preprint: biorxiv.org/content/10.1101/…

Now @biorxivpreprint: impacts of the maternal #microbiota and microbial #metabolites on fetal intestine, brain and placenta! With @ville_koistinen @karkkainen_olli @KatiHanhineva @antagomir & co. Comments welcome! #metabolomics biorxiv.org/content/10.1101/…

Got funded by @SuomenAkatemia 🤩!!! Next 4 years, we will investigate how maternal microbial metabolites and #extracellularvesicles #EVs modulate fetal development of the intestinal immune system @HelsinkiOne @helsinkiuni.💎 collaboration with @AfektaTech @EVgroupUH & others!

How does the pregnant dam train the fetal immune system? We found very few live bacteria in C-section calves at birth, but there was already some bacterial DNA in their intestine. @helsinkiuni @HelsinkiOne #microbiota #microbiome #newborn #fetus #birth frontiersin.org/article/10.3…

Mother's #microbiota begins to train the baby's immune system already before birth. But how does it happen? Our latest research now out as preprints! @helsinkiuni @helsinkione #hyeltdk (1/3)