3:30–4:30 pm Maria Geoppert-Mayer Lecture Hall
Decoding the complexity of microbial community through the lens of disordered systems
Ada Altieri, Université Paris Cité
The remarkable biodiversity observed in natural ecosystems has recently attracted significant interest, engaging not only ecologists but also theoretical physicists. In this talk, I will address key questions in theoretical ecology by focusing on the Generalized Lotka-Volterra (GLV) model, which incorporates random species interactions and demographic fluctuations [1]. I will reveal the emergence of a rich, and ultimately hierarchical, structure of the equilibria and show how the associated dynamics exhibit a glass-like slowdown. I will then apply this framework to offer a proof of concept for capturing the complexity of the human gut microbiota. By analyzing metagenomic data from healthy individuals and patients suffering from inflammatory bowel diseases, I will link distinct physiological states of the human gut microbiome to different noise-driven and disorder-driven regimes within the GLV model [2]. Finally, I will discuss possible extensions to incorporate non-logistic growth functions [3], suggesting these as stabilizing mechanisms regardless of increasing diversity in the community.
References:
[1] A. Altieri, F. Roy, C. Cammarota, G. Biroli, Phys. Rev. Lett. 126 (2021)
[2] J. Pasqualini, A. Maritan, A. Rinaldo, S. Facchin, E. V. Savarino, A. Altieri* & S. Suweis*, arXiv:2406.07465, to appear in eLife (2025)
[3] I. Hatton, O. Mazzarisi, A. Altieri, M. Smerlak, Science 383 (2024)