Dr Petra Louis | The 51cg

Dr Petra Louis

Senior Research Fellow

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Email Address

p.louis@abdn.ac.uk

Telephone Number

+44 (0)1224 438735

Office Address

Dr. Petra Louis

Microbiology Group

Gut Health Theme

The Rowett Institute

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Foresterhill

Aberdeen AB25 2ZD

School/Department

School of Medicine, Medical Sciences and Nutrition

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 51cg 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.

Qualifications

Diploma Biology
1992 - University of Bonn, Germany
PhD Microbiology
1996 - Univesity of Bonn, Germany

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

Research

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.

Research Specialisms

Microbiology
Biochemistry
Molecular Biology
Ecology

Our research specialisms are based on the Higher Education Classification of Subjects (HECoS) which is , published under the licence.

Publications

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Biography

Qualifications

Prizes and Awards

Research Overview

Research Specialisms

Noncanonical Surface Glycoconjugates from Bacteroides stercoris DSM 19555 Reprogram Innate Immune Responses

Predicting responses to prebiotic fibres: linking microbiota, function and clinical outcomes

Metabolism of β-mannans by representative, understudied Bacillota species from the human colon

Big breakfast diet composition impacts on appetite control and gut health: a randomised weight loss trial in adults with overweight or obesity

Integrating microbiomes into One Health: insights from the 2025 One Health World Microbiome Partnership Summit

Decoding a Gut Commensal Signal: Structural and Immunological Profiling of Segatella copri Lipopolysaccharide

Gut microbiota-derived short-chain fatty acids and their role in human health and disease

Roles of human colonic bacteria in pectin utilization and associated cross-feeding networks revealed using synthetic co-cultures

Fava bean and buckwheat are sustainable food sources which support satiety and beneficially modulate several biomarkers, bacteria and metabolites associated with human health

Dietary fibre optimisation in support of global health

Why does increased microbial fermentation in the human colon shift toward butyrate?

Gorse (Ulex europeaus) wastes with 5,6-dimethyl benzimidazole supplementation can support growth of vitamin B12 producing commensal gut microbes

Habitual consumption of high-fibre bread fortified with bean hulls increased plasma indole-3-propionic concentration and decreased putrescine and deoxycholic acid faecal concentrations in healthy volunteers

Effect of feed concentration and residence time on anaerobic fermentation in CSTR and SBR to produce short-chain organic acids

Beyond purified dietary fibre supplements: compositional variation between cell wall fibre from different plants influences human faecal microbiota activity and growth in vitro

Process-based modelling of Microbial community dynamics in the human colon

Microbial lactate utilisation and the stability of the gut microbiome

Long-term personalized low FODMAP diet improves symptoms and maintains luminal Bifidobacteria abundance in irritable bowel syndrome

Higher total faecal short-chain fatty acid concentrations correlate with increasing proportions of butyrate and decreasing proportions of branched-chain fatty acids across multiple human studies

Distribution, organization and expression of genes concerned with anaerobic lactate utilization in human intestinal bacteria

Immune Responsiveness to LPS Determines Risk of Childhood Wheeze and Asthma in 17q21 Risk Allele Carriers

Dietary fibre complexity and its influence on functional groups of the human gut microbiota

Prebiotic fructans have greater impact on luminal microbiology and CD3+ T cells in healthy siblings than patients with Crohn’s disease: a pilot study investigating the potential for primary prevention of inflammatory bowel disease

Human gut Faecalibacterium prausnitzii deploy a highly efficient conserved system to cross-feed on β-mannan-derived oligosaccharides

Maturation of the gut microbiome during the first year of life contributes to the protective farm effect on childhood asthma

Prevalent Human Gut Bacteria Hydrolyse and Metabolise Important Food-Derived Mycotoxins and Masked Mycotoxins

Pivotal roles for pH, lactate and lactate-utilizing bacteria in the stability of a human colonic microbial ecosystem

Comparative genetic and physiological characterisation of Pectinatus species reveals shared tolerance to beer-associated stressors but halotolerance specific to pickle-associated strains

Vitamin biosynthesis by human gut butyrate-producing bacteria and cross-feeding in synthetic microbial communities

Analysis of 1321 Eubacterium rectale genomes from metagenomes uncovers complex phylogeographic population structure and subspecies functional adaptations

β-glucan is a major growth substrate for human gut bacteria related to Coprococcus eutactus

Feasibility of microwave-assisted pre-treatment of lignocellulosic feedstocks to produce added-value chemicals and materials

Anthocyanin-enriched bilberry extract attenuates glycaemic response in overweight volunteers without changes in insulin

Comparison of meat versus soya based high-protein diets on faecal microbiota and microbial metabolites

Flintibacter

Randomised clinical trial: Bifidobacterium lactis NCC2818 probiotic vs placebo, and impact on gut transit time, symptoms, and gut microbiology in chronic constipation

The effect of prunes on stool output, gut transit time and gastrointestinal microbiota: a randomised controlled trial

Formate cross-feeding and cooperative metabolic interactions revealed by transcriptomics in co-cultures of acetogenic and amylolytic human colonic bacteria

Dietary fibers inhibit obesity in mice, but host responses in the cecum and liver appear unrelated to fiber-specific changes in cecal bacterial taxonomic composition

microPop: modelling microbial populations and communities in R

Mutual Interaction of Phenolic Compounds and Microbiota: Metabolism of Complex Phenolic Apigenin-C- and Kaempferol-O-Derivatives by Human Fecal Samples

Porcine small and large intestinal microbiota rapidly hydrolyze the masked mycotoxin deoxynivalenol-3-glucoside and release deoxynivalenol in spiked batch cultures in vitro

Sporulation capability and amylosome conservation among diverse human colonic and rumen isolates of the keystone starch-degrader Ruminococcus bromii

Specific substrate-driven changes in human faecal microbiota composition contrast with functional redundancy in short-chain fatty acid production

Different Substrate Preferences Help Closely Related Bacteria To Coexist in the Gut

Prebiotic potential of pectin and pectic oligosaccharides to promote anti-inflammatory commensal bacteria in the human colon

Chlorogenic acid versus amaranth's caffeoylisocitric acid – Gut microbial degradation of caffeic acid derivatives

Diet Low in FODMAPs Reduces Symptoms in Patients with Irritable Bowel Syndrome and Probiotic Restores Bifidobacterium Species: a Randomized Controlled Trial

The impact of nutrition on intestinal bacterial communities

Formation of propionate and butyrate by the human colonic microbiota

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