Probiotic could facilitate gut pathogen infection in the absence of fibre, study reveals

Published: 4-Jun-2024

The study highlights the duality of A. muciniphila in preventing food borne disease, and how its activities are strongly linked to dietary fibre intake

A novel study run by the Luxembourg Institute of Health shed light on the complex relationship between gut bacteria, pathogens and diet. 

The research team, led by Prof. Mahesh S. Desai, investigated which bacteria commonly found in the gut could facilitate the infection of pathogens targeting the gut, and how this interaction could be impacted by dietary choices. 

Their findings reveal a surprising duality: Akkermansia muciniphila, a bacterium commonly found in the gut microbiome, can either bolster or weaken the gut's defences against harmful bacteria depending on the intake of dietary fibre. 

This research underscores that friendly bacteria in the gut synergise with pathogens in the face of a fibre-deprived diet, which calls for considering a holistic approach when designing probiotic interventions.


The results

Published in the journal Molecular Systems Biology, the research sheds light on the "Dr Jekyll and Mr Hyde" persona of this bacterium, showcasing its ability to be either beneficial or detrimental to our ability to resist pathogen infections depending on dietary context.

Through a series of experiments using gnotobiotic mice harbouring a synthetic human microbiota, the researchers demonstrated that A. muciniphila plays a pivotal role in modulating infection dynamics of the gut mucosal pathogen Citrobacter rodentium, which is a model for human enteropathogenic and enterohaemorrhagic Escherichia coli.


Fibre deprivation changes everything 

The research elucidates that under conditions of dietary fibre deprivation, A. muciniphila renders the host more vulnerable to mucosal pathogen colonisation by increasing mucus penetrability. 

However, on a fibre-sufficient diet, the presence of A. muciniphila paradoxically reduces pathogen load, highlighting its context-dependent beneficial effects.

"Our findings challenge conventional wisdom surrounding the role of A. muciniphila in gut health,” explains the first author of this study, Dr Mathis Wolter. "While it's widely regarded as a potential probiotic, our study emphasises the importance of considering dietary context in harnessing its beneficial effects."


On a fibre-sufficient diet, the presence of A. muciniphila paradoxically reduces pathogen load


A. muciniphila as a biomarker for pathogen susceptibility 

The implications of this research extend beyond the realm of gut health, offering insights into the broader dynamics of microbial ecology and disease susceptibility. 

By identifying A. muciniphila as a potential biomarker species for predicting susceptibility to enteric pathogens, the study paves the way for targeted interventions to mitigate the burden of food borne infections.

"As we navigate the complex landscape of human health, understanding the interplay between diet, microbiota and disease is paramount," adds Desai. "Our research highlights the need for a nuanced approach to probiotic therapies, taking into account the context-dependent nature of microbial interactions.”

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