Are bacteria building toxic biofilms in your gut?



Think of a corroded pipe. Now think of an inflamed gut. These conditions may be caused by similar bacteria. Sulphate reducing bacteria (SRB) are anaerobic bacteria, common in the environment and the gastrointestinal tract. They produce corrosive hydrogen sulphide gas, which is known to attack metal structures and cause problems in industry. Recent work has also suggested they may be involved in gut inflammation in diseases like ulcerative colitis, and colorectal cancers.

Biofilm formation allows bacteria to grow in a protected state with higher resistance to antibiotics. Biofilms are often associated with harmful effects such as increased pathogenesis or corrosive production. Understanding SRB lifestyle and how to prevent deleterious or antibiotic-resistant growth forms is an essential step for the design of biocontrol strategies.

This project aims to use SRB strains from the gut and the environment to investigate the nature of SRB biofilms and how the transition between planktonic and biofilm growth is controlled. Gene expression, metatranscriptomics and quorum sensing will be utilised together with advanced microscopy to understand the role of SRB biofilms in gastrointestinal tract colonisation and persistence and to identify targets to stop or disperse biofilm formation in the gut environment.

The applicant will join the diverse and dynamic interdisciplinary teams of Narbad and Juge groups at Quadram Institute Bioscience, working on the interactions between the gut microbiota and human health and the development of biocontrol strategies. The work plan will involve training in state-of-the-art techniques of biofilm analysis, anaerobic and molecular microbiology, metagenomics, metatranscriptomics and bioinformatics. The applicant will also have the opportunity to interact with related projects. We are looking for a highly self-motivated individual who is capable of independent thinking with an aptitude for laboratory work and a strong interest in microbiology and gut health.


1. Wegmann U, Nueno Palop C, Mayer MJ, Crost E, Narbad A (2017) Complete Genome Sequence of Desulfovibrio piger FI11049. Genome Announc 5:e01528-16.

2. Sayavedra L, Li T, Bueno Batista M, Seah BKB, Booth C, Zhai Q, Chen W, Narbad A Desulfovibrio diazotrophicus a sp. nov., a sulfate reducing bacterium from the human gut capable of nitrogen fixation. Environ Microbiol. 2021

3. Garcia-Gutierrez E, Walsh CJ, Sayavedra L, Diaz-Calvo T, Thapa D, Ruas-Madiedo P, Mayer MJ, Cotter PD, Narbad A. (2020) Genotypic and Phenotypic Characterization of fecal Staphylococcus epidermidis isolates suggests plasticity to adapt to different human body sites. Front Microbiol 11:688..