Guillaume Méric

@[email protected]
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Associate Prof: University of Bath (from July 25)
Clinical Affiliate: Baker HDI (Melbourne, Australia).
Human microbiomes, infectious diseases & pathogen genomics.
Google Scholarhttps://scholar.google.co.uk/citations?user=UEDlh7kAAAAJ&hl=en
Lab websitehttps://mericlab.com/
Guillaume MéricNov 4, 2022

We're critically lacking clinical microbiome studies from non-European populations, which negatively impacts the precise understanding of disease.

In this 16S-based study, the microbiota of Pakistani adults (n=94), a population known to have extremely high prevalence of #T2D , is described.

▶️ Prevalence of Atopobiaceae seems unique to the Pakistani pop.
▶️ Pakistanis w/T2D have different microbial signatures than other pop. (high abundance of Libanicoccus/Parolsenella)

https://www.tandfonline.com/doi/full/10.1080/19490976.2022.2142009?af=R

Unique Pakistani gut microbiota highlights population-specific microbiota signatures of type 2 diabetes mellitus

Biogeographic variations in the gut microbiota are pivotal to understanding the global pattern of host–microbiota interactions in prevalent lifestyle-related diseases. Pakistani adults, having an e...

Taylor & Francis
Guillaume MéricNov 4, 2022

What's not to like in studying the #microbiome from virtually the entire species of a critically endangered animal? The kākāpō recovery team strikes again in a recent preprint.

Interesting attempts to link microbiota diversity to host genotype variation too. Hopefully impactful for future conservation.

https://www.biorxiv.org/content/10.1101/2022.10.31.514450v1?rss=1

Guillaume MéricNov 4, 2022

It's been described in the past, but I'm always a bit astonished to see that sub-gingival #pathobionts 🦷 associate with #myocardial infarction risk 💔.

Testing 160 acute MI patients with varying degrees of clinical #periodontitis enrolled in this cross-sectional study, authors link increased abundance of subgingival #Porphyromonas gingivalis and overexpression of virulence factors to worse cardiac outcomes and CAD burden.

Paper: https://www.nature.com/articles/s41598-022-19154-z

Myocardial infarction risk is increased by periodontal pathobionts: a cross-sectional study - Scientific Reports

To establish the role of periodontal pathobionts as a risk factor for myocardial infarction, we examined the contribution of five periodontal pathobionts and their virulence genes’ expressions to myocardial injury (Troponin-I) and coronary artery disease burden (SYNTAX-I scores) using hierarchical linear regression. Pathobiont loads in subgingival-plaques and intra-coronary-thrombi were compared. Troponin-I release increased with one 16S rRNA gene copy/ng DNA of Porphyromonas gingivalis (β = 6.8 × 10–6, 95% CI = 1.1 × 10–7–2.1 × 10–5), one-fold increased expressions of fimA (β = 14.3, 95% CI = 1.5–27.1), bioF-3 (β = 7.8, 95% CI = 1.1–12.3), prtH (β = 1107.8, 95% CI = 235.6–2451.3), prtP (β = 6772.8, 95% CI = 2418.7–11,126.9), ltxA (β = 1811.8, 95% CI = 217.1–3840.8), cdtB (β = 568.3, 95% CI = 113.4–1250.1), all p < 0.05. SYNTAX-I score increased with one 16S rRNA gene copy/ng DNA of Porphyromonas gingivalis (β = 3.8 × 10–9, 95% CI = 3.6 × 10–10-1.8 × 10–8), one-fold increased expressions of fimA (β = 1.2, 95% CI = 1.1–2.1), bioF-3 (β = 1.1, 95% CI = 1–5.2), prtP (β = 3, 95% CI = 1.3–4.6), ltxA (β = 1.5, 95% CI = 1.2–2.5), all p < 0.05. Within-subject Porphyromonas gingivalis and Tannerella forsythia from intra-coronary-thrombi and subgingival-plaques correlated (rho = 0.6, p < 0.05). Higher pathobiont load and/or upregulated virulence are risk factors for myocardial infarction. Trial registration: ClinicalTrials.gov Identifier: NCT04719026.

Nature
Guillaume MéricNov 3, 2022

Very exhaustive (recent? October...) review in Cell Metabolism on the #gut #liver axis, summarizing what is known on the associated impact on #gastrointestinal #health and disease and the effect of perturbations of the intestinal barrier and host-microbe interactions.

https://www.sciencedirect.com/science/article/pii/S1550413122004077

Guillaume MéricNov 3, 2022

People with IBS are more likely to develop #colorectal #cancer, and the role of the #microbiota is unclear. In this study published in #Science a few weeks ago, authors screen bacteria isolated from individuals with #IBS for genotoxic effect & discover a new family of DNA damage-inducing metabolites called indolimines. #Morganella morganii is found to produce it and exacerbates tumours in a mouse CRC model. Neat work!

https://www.science.org/doi/10.1126/science.abm3233

Guillaume MéricNov 3, 2022

Nice and exhaustive review on the current state of microbiota-based interventions to modulate gut ecology/immunity. Good read if you're interested in the promise of #microbiome #precisionmedicine.

https://www.nature.com/articles/s41385-022-00564-1

Microbiome-based interventions to modulate gut ecology and the immune system - Mucosal Immunology

The gut microbiome lies at the intersection between the environment and the host, with the ability to modify host responses to disease-relevant exposures and stimuli. This is evident in how enteric microbes interact with the immune system, e.g., supporting immune maturation in early life, affecting drug efficacy via modulation of immune responses, or influencing development of immune cell populations and their mediators. Many factors modulate gut ecosystem dynamics during daily life and we are just beginning to realise the therapeutic and prophylactic potential of microbiome-based interventions. These approaches vary in application, goal, and mechanisms of action. Some modify the entire community, such as nutritional approaches or faecal microbiota transplantation, while others, such as phage therapy, probiotics, and prebiotics, target specific taxa or strains. In this review, we assessed the experimental evidence for microbiome-based interventions, with a particular focus on their clinical relevance, ecological effects, and modulation of the immune system.

Nature
Guillaume MéricNov 3, 2022

Interesting functional #microbiome study published in Cell Host & Microbes recently on how psychoactive drugs interact with the gut microbiome and addiction.

Authors found that after exposing mice to cocaine ▶️ increase in norepinephrine ▶️ increase in #Proteobacteria colonization ▶️ depletion of glycine in gut/CSF/blood ▶️ facilitation of cocaine-induced addiction-like behaviors.

https://www.sciencedirect.com/science/article/pii/S193131282200470X