10/ Our work demonstrates how a single virulence factor—cholera toxin—remodels epithelial metabolism to generate L-lactate in the small intestine, highlighting how cAMP-modulating toxins may have co-evolved with pathogens to reshape host metabolic landscapes to promote pathogen growth during disease

9/ L-lactate is an emerging gut metabolite that supports the growth of enteric pathogens, including Salmonella (Gillis et al., 2018) and C. jejuni (Sinha, 2024) in the large intestine. Epithelial-derived lactate also fuels Enterobacteriaceae expansion in the cecum (Taylor et al., 2022)

8/ This work reveals how a bacterial toxin reprograms epithelial cell metabolism to generate a novel growth substrate in the small intestine. We show that V. cholerae leverages this host-derived metabolite to expand during CT-induced disease

7/ Where’s the L-lactate coming from? Using mice lacking LDHA specifically in intestinal epithelial cells, we show the epithelium is the main source. In these mice, V. cholerae's LldD-dependent fitness is significantly reduced—revealing that CT rewires epithelial metabolism to fuel pathogen growth

6/ Strains lacking CT did not show this advantage — but adding exogenous CT rescued the fitness defect, confirming that CT itself is responsible for generating the L-lactate–rich environment that V. cholerae exploits via LldD to grow during infection

5/ To test if V. cholerae exploits host-derived L-lactate, we turned to the suckling mouse model. Consistent with our hypothesis, CT-producing wild-type bacteria had a fitness advantage over the lldD mutant in the small intestine

4/ We show that V. cholerae’s previously uncharacterized L-lactate dehydrogenase (LldD) — upregulated in a CT-dependent manner during infection — functions to metabolize L-lactate during both in the presence of oxygen and nitrate

3/ We found that CT increases expression of host lactate dehydrogenase A (LDHA) in small intestinal epithelial cells. 🧪 LDHA converts pyruvate → L-lactate, pointing to epithelial-derived L-lactate as a key metabolite generated during cholera disease

2/ We previously found CT creates a unique gut niche—iron-starved but rich in long-chain fatty acids and L-lactate (PMID: 31367037, 2019). But how CT manipulates host metabolism to generate this niche was still a mystery.

1/ Excited to share the first preprint from my lab! 🎉

My postdoc Paz asked how cholera toxin (CT) helps Vibrio cholerae thrive in the gut.

Turns out, CT rewires epithelial metabolism toward L-lactate production—fueling pathogen growth in the small intestine during disease

Saddened to learn of the passing of Moselio "Elio" Schaechter—Distinguished Professor at Tufts, SDSU and UCSD—humanist and visionary leader in the fields of microbiology and scientific communication—mentor, friend, and inspiration to me and so many others

Small Things Considered
Big Things Achieved

The Raffatellu, Chu @chulab.bsky.social Rivera-Chavez @fabianrchavez.bsky.social labs were well represented at the #standupforscience @standupforscience.bsky.social event at #UCSD today!

Microbiome science needs more microbiologists- A new commentary authored by myself and @abaumler.bsky.social www.nature.com/articles/s41...

Can classical microbiology transform microbiome research? 🤔 Our new article explores how integrating microbiological concepts can build a stronger theoretical framework for microbiome sciences. 🌟 Read more about the path to hypothesis-driven research:

All brought to you by the good people at OMICS International who own and operate“more than 500 peer-reviewed journals”

So do I

(A) just ignore this?
(B) do something?

If you chose the latter, what do you suggest I do?

Any replies with some guidance or cynical humor welcome

Academic Skyers: I am compiling a list of policies and statements from various universities about how they are handling the "pause" in terms of stopping expenditures (or not).

Please respond to this post with your institution and materials.

THANK YOU!

We are lookkng for a behavioral neurologist to join us at Stanford in sunny California! Feel free to reach out to me with any questions! 🌞😊🧠

Beautiful paper from the Elizabeth Winzeler laboratory at UC San Diego out today in Science building a predictive model of malaria drug resistance by analyzing the genomes of 724 parasite genomes evolved in the lab to resist one of 118 different antimalarial compounds

today.ucsd.edu/story/a-new-...

An updated list with those added who wanted to join go.bsky.app/VVLoMPx

Nothing is better than your past trainees successes

Congrats!

Believe it or not, GRC has told me we need more registered applicants or this meeting might not survive! Please don't let that happen if you can afford to attend 🙏

This will me my fist blueet! Microbial N-Acyl lipids have been shown to regulate glucose, pain etc among other things. Therefore Helena, Vincent and Martijn asked the question - are there more and if so what types? And boy did they find some www.biorxiv.org/content/10.1...

What I said Jan 2022...

So if we all agree that we will be living with respiratory viruses in the future & that they have an airborne transmission component, can we agree that it is essential to clean indoor air using filtration & ventilation for all schools/businesses so we can get our lives back?