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About us Faculty of Science and Engineering PhD ceremonies

Gut Bacteroidales: antimicrobial potencies and host-bacteria interactions

PhD ceremony:M.V. Fernandez Cantos, M
When:July 01, 2024
Start:11:00
Supervisors:O.P. (Oscar P) Kuipers, prof. dr. G.N. (Gert) Moll
Where:Academy building RUG
Faculty:Science and Engineering
Gut Bacteroidales: antimicrobial potencies and host-bacteria
interactions

The primary focus of the thesis of Victoria Fernandez Cantos was the exploration of the metabolic and probiotic features of Bacteroidales bacteria.

Fernandez Cantos: 'Within the human gut microbiota, Bacteroidales bacteria represent the predominant Gram-negative order and one of the most stable components. As the knowledge about gut microbiota increases, members of this order have been previously suggested as candidates for next-generation probiotics (NGPs) due to their beneficial traits. Nevertheless, they have also been implicated in disease and infection, including Metabolic dysfunction-associated fatty liver disease (MAFLD).

The primary focus of this thesis was the exploration of the metabolic and probiotic features of Bacteroidales bacteria. First, we explored the RiPP biosynthetic potential by conducting an in silico screening with the web-based tool BAGEL4 on 1136 Bacteroidales strains, which unveiled a consistent association between C39 peptidase containing ATP-binding transporters (PCATs) and precursor peptides with GG-motifs. The evaluation of the expression and antimicrobial activity of two of the RiPP BGCs revealed that these BGCs remain silent under laboratory conditions. Second, the production of additional metabolites that may mediate microbe-host and microbe-microbe interactions was evaluated using an untargeted LC-MS/MS approach. Several bioactive metabolites are uncovered in the study, including biogenic amines and collagen-derived metabolites. This last group of metabolites is suggestive of collagenase activity. Finally, a set of Bacteroidales strains is evaluated for their probiotic traits through antimicrobial activity assays and human in vitro models. Notably, Bacteroides sp. 4 1 36 exhibited promising traits due to its antimicrobial activity, reduction of gut permeability, and improvement in free fatty acid clearance, positioning it as a compelling candidate for therapeutic interventions in MAFLD.'