Nutritional microbiomics & human physiology

We integrate neuromicrobiology, xenobiotic–microbiome interplay, and next-generation biotics from mechanism to translation. Our work maps how gut microbes and their extracellular vesicles (MEVs) traffic neuroactive metabolites accross the gut-brain axis. We explore the dynamics of microbiome neurometabolism, the genesis of MEVs, and the resulting interplay with the host. This research program also investigate the modulatory effects of microbiome-targeted nutritional interventions (pre-, pro-, post-, and synbiotics) on human physiology.

Neuromicrobiology

MEVs convey γ-aminobutyric acid (GABA) and other neuroactive metabolites across epithelial and blood–brain barriers.

Xenobiotic interplay

Psychotropics and other therapeutics act as off-target antimicrobials; targeted probiotics mitigate drug-induced dysbiosis.

Next-generation biotics

Nutrition-driven probiotics, prebiotics, synbiotics, and postbiotics reinforce barrier function, immune system, and food safety.

Hammami Lab

Theme I

Neuromicrobiology & psychobiotics

Beyond nutrient digestion and production, the gut microbiome also functions as personalized polypharmacy, where bioactive metabolites that our microbes excrete or conjugate may reach systemic circulation and impact all organs, including the brain. Several studies have demonstrated correlations between the gut microbiome and the central nervous system sparking an exciting new research field, neuromicrobiology. We study strain-specific production of neurotransmitters (e.g. GABA, dopamine, serotonin). We demonstrate, through multi-omics profiling, that MEVs transport neuroactive cargo across epithelial and blood–brain barriers.

Gut–brain axis schematic showing microbe-derived extracellular vesicles and metabolites crossing epithelial and blood-brain barriers.
Frontiers in Microbiology 14:1098412 (2023).

Recent evidence

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Theme II

Xenobiotic–microbiome interplay

Growing evidence indicates that non-antibiotic therapeutics, including psychotropic medications (antidepressants, antipsychotics, mood stabilizers, anxiolytics, etc.), significantly impact human health by modulating gut microbiome composition and metabolism. Psychotropics among other therapeutics often carry antimicrobial activity that confounds microbiome-related studies. Using continuous colon models and multi-omics technologies, we study how xenobiotics modulate microbiome structure and metabolism. We investigate role of adjuvant biotic strategies to mitigate gut microbiome dysbiosis.

Schematic of xenobiotic–microbiome interactions and feedback on host physiology.
Progress in Neuro-Psychopharmacology and Biological Psychiatry 108:110182 (2021).

Recent evidence

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Theme III

Next-generation biotics

Microbiome-targeted interventions are seen as promising adjunctive treatments (pre-, pro-, post-, and synbiotics), but the mechanisms underlying host-microbiome interactions have yet to be established, thus preventing informed evidence-based therapeutic applications. With ex vivo continuous colon systems, we study how fibers, beneficial microbes, and MEVs modulate community structure and metabolism, and host physiology. We develop microbiota-targeted interventions aiming to restore gut dysbiosis, reinforce epithelial defense, and suppress foodborne pathogens across human and animal applications.

Figure 8 fillustrating microbiome-targeted interventions and outcomes.
Microbiology Spectrum 13(2):e01368-24(2024).

Recent evidence

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