Dr Petra Louis

Biography

Petra Louis is a molecular microbiologist with an interest in the human gut microbiota, diet and health. She obtained her Diploma in Biology and PhD in Microbiology from the University of Bonn, Germany, where she conducted research on osmoadaptation in halophilic bacteria. She undertook post-doctoral research at the University of Aberdeen on stress responses in Escherichia coli and on RNA secondary structure melting during translation in yeast, before taking up a position as principal investigator at the Rowett Institute in Aberdeen in 2002.

Her research concentrates on the metabolism of the microbial community that inhabits the human intestine and how it can be modulated by diet to improve human health, with a particular emphasis on short-chain fatty acid production from dietary non-digestible carbohydrates. She utilises a wide range of technical approaches, including strictly anaerobic microbiology, molecular microbial community analysis, -omics technologies and mathematical modelling, to investigate which microbes are instrumental for primary fibre degradation and how different microbial community members interact with each other during fibre breakdown and fermentation product formation. Her work contributes to the development of effective and personalised nutritional strategies to improve human health via actions of the gut microbiota.

Prizes and Awards

PhD thesis award of the German Society for General and Applied Microbiology (VAAM) 1996

Clarivate (Web of Science) highly cited researcher: 2018-2025

Member of the Rowett Gut Microbiology Group, who were runners up in the International Global Grants for Gut Health Nature Awards Research Group Prize 2023 - read more HERE

Research Overview

The microbial community in the human large intestine consists of a diverse range of bacteria that break down complex nutrients of dietary and host origin. The members of this ecosystem form a complex metabolic network in which the product of one group can serve as substrate for another group. Overall, this leads to the accumulation of mainly three organic acids, acetate, propionate and butyrate, which are partially absorbed by the colon and serve as an additional energy source for the human host. Butyrate is of special interest, as it serves as the preferred energy source for the colonic wall and thus contributes to the proper functioning of the gut. It has also been claimed to be protective against colon cancer and inflammatory bowel disease through effects on host gene expression and cellular development of the colon. Propionate also influences host physiology and its potential effects on host satiety is of particular interest in view of the current obesity epidemic.

Dietary intakes can influence the microbial gut community and shift the balance between different functional bacterial groups, with potential consequences for host health. Our research concentrates on the microbial metabolism of dietary non-digestible carbohydrates, with a particular emphasis on short-chain fatty acid production. We utilise are wide range of technical approaches, including strictly anaerobic microbiology of pure strains and mixed microbial consortia, molecular microbial community analysis of in vitro and human dietary studies, -omics technologies, enzymology and mathematical modelling.