Journal: Gut Microbes

Article Title: Novel bacterium Enterocloster sp. M3 promotes colorectal tumorigenesis via the production of the carcinogen styrene

doi: 10.1080/19490976.2026.2630481

Figure Lengend Snippet: Dysregulation of DNA repair by M3. (A) Pathway enrichment analysis showing DNA damage and repair-related pathways significantly altered in colon cancer cells treated with M3 supernatant versus E. coli supernatant. (B) M3 supernatant promoted G1-S cell cycle transition in colon cancer cells, concurrent with modulation of key cell cycle regulatory proteins. (C) Representative confocal immunofluorescence images and quantitation of Ki-67 staining in undifferentiated organoids. (D) RNA sequencing demonstrating significant downregulation of and Chk1, phosphorylated proteins of which involved in DNA repair, in M3-treated cells versus controls (Log2 fold-changes; significance by Poisson distribution). (E1 & E2) IHC staining revealing decreased pChk1 in colon tissues of M3-treated mice compared to controls ( E. coli or PBS). (F) IHC staining showing decreased pChk1 in differentiated organoids treated with M3 supernatant compared to controls ( E. coli supernatant or broth). Data are presented as mean ± SD (B, C, E) and compared using unpaired t-tests.

Article Snippet: Escherichia coli strain MG1655 (700926, ATCC, USA), a non-pathogenic human intestinal bacterium, served as a bacterial control.

Techniques: Immunofluorescence, Quantitation Assay, Staining, RNA Sequencing, Immunohistochemistry

Journal: Gut Microbes

Article Title: Novel bacterium Enterocloster sp. M3 promotes colorectal tumorigenesis via the production of the carcinogen styrene

doi: 10.1080/19490976.2026.2630481

Figure Lengend Snippet: Potential oncogenic metabolites produced by M3. (A) Volcano plot of differentially abundant metabolites in M3 supernatant versus mock-cultured broth (two independent cultures per group) from non-targeted metabolomics. (B) Heatmap of eight increased metabolites of interest and classification of decreased metabolites in M3 supernatant versus broth. (C) Top 10 metabolites upregulated or decreased in M3 supernatant compared to mock-cultured broth as identified by non-targeted LC-MS and orthogonal partial least squares discriminant analysis (OPLS-DA). Shown VIP (Variable Importance in Projection) is the first component of the OPLS-DA model. (D) Targeted GC/LC-MS quantification of metabolites produced by M3, E. coli, and E. aldenensis ( Ea ). (E) Enrichment of the KEGG pathways related to tyrosine and phenylalanine metabolism and styrene degradation. Data are presented as mean ± SD (D) and compared using ordinary one-way ANOVA with Tukey’s multiple comparisons test (D).

Article Snippet: Escherichia coli strain MG1655 (700926, ATCC, USA), a non-pathogenic human intestinal bacterium, served as a bacterial control.

Techniques: Produced, Cell Culture, Liquid Chromatography with Mass Spectroscopy

Journal: Gut Microbes

Article Title: Novel bacterium Enterocloster sp. M3 promotes colorectal tumorigenesis via the production of the carcinogen styrene

doi: 10.1080/19490976.2026.2630481

Figure Lengend Snippet: Potential oncogenic metabolites detected in stools from M3-treated mice. (A) Fecal metabolites from M3-treated mice significantly promoted cell growth compared to those from mice treated with E. coli or PBS. (B) Volcano plot of differentially abundant metabolites in stools from M3-treated mice compared to controls. All metabolites in the volcano plots meet Class B(i) or B(ii) level in non-targeted metabolomics and have VIP (Variable Importance in Projection) scores > 1 by OPLS-DA analysis. (C) Heatmap of differentially abundant metabolites identified in stools. (D) Schematic of metabolites directly produced by M3 and those generated through downstream in vivo metabolism. (E) Targeted GC-MS analysis showing significantly elevated styrene levels in stools from M3-treated mice compared to controls. (F) Positive correlation between fecal styrene levels and M3 abundance (quantified by qPCR) in M3-treated mice. (G) Differentially abundant metabolites identified in M3 supernatant and/or stools of M3-treated mice were consistently elevated or decreased in the stools of CRC patients compared to control subjects (late-onset: CRC n = 130, control n = 97; early-onset: CRC n = 114, control n = 100). Data are presented as mean ± SD (A, E) and compared using two-way ANOVA with Tukey’s multiple comparisons test (A), Mann-Whitney test (E), or Pearson’s correlation (F).

Article Snippet: Escherichia coli strain MG1655 (700926, ATCC, USA), a non-pathogenic human intestinal bacterium, served as a bacterial control.

Techniques: Produced, Generated, In Vivo, Gas Chromatography-Mass Spectrometry, Control, MANN-WHITNEY

Journal: Gut Microbes

Article Title: Novel bacterium Enterocloster sp. M3 promotes colorectal tumorigenesis via the production of the carcinogen styrene

doi: 10.1080/19490976.2026.2630481

Figure Lengend Snippet: Molecular mechanism of styrene biosynthesis in M3. (A) Schematic of microbial styrene biosynthesis pathways based on KEGG analysis and literature. (B) Proteomic and genomic identification of eight enzymes (E1-8) involved in phenylalanine synthesis in M3. (C) Elevated phenylalanine-ammonia lyase (PAL)-like and trans-Cinnamic acid (tCA)-to-styrene conversion activities in M3 compared to E. coli and E. aldenensis ( Ea ), indicating the existence of functional isoenzymes. (D) Identification of three ammonia-lyases, including aspartate ammonia-lyase (AAL), diaminopropionate ammonia-lyase (DAPAL), and Threonine ammonia-lyase; Lactobacillus paracasei AAL was reported to exhibit PAL-like activity. (E) Elevated protein levels of six decarboxylases (FDC isozyme candidates) in M3 versus Ea . Protein levels shown in (D) and (E) are based on Ea proteome reference quantification. (F) 3D model of M3-AAL with scrambling mutations in the catalytic MIO (4-methylideneimidazole-5-one) motif, alongside PAL-like activity of recombinant wildtype versus mutant M3-AAL. (G) 3D model of M3-UROD with mutations in the acetate-positioning region, alongside tCA-to-styrene conversion by recombinant wildtype versus mutant M3-UROD. (H) Elevated PAL-like activity in M3-treated mouse stools compared to controls. (I) Positive correlation between fecal M3 abundance, quantitated by qPCR, and PAL-like activity. Data are presented as mean ± SD (C, F-I) and analyzed using ordinary one-way ANOVA with Tukey’s multiple comparisons test (C, F, H), unpaired t-test (D, E), two-way ANOVA with Tukey’s multiple comparisons test (G), or Pearson’s correlation (I).

Article Snippet: Escherichia coli strain MG1655 (700926, ATCC, USA), a non-pathogenic human intestinal bacterium, served as a bacterial control.

Techniques: Functional Assay, Activity Assay, Recombinant, Mutagenesis

Journal: iScience

Article Title: Aerobicity stimulon in Escherichia coli revealed using multi-scale computational systems biology of respiratory variants

doi: 10.1016/j.isci.2026.114715

Figure Lengend Snippet: Impact of carbon source on ETS variants Metabolic flux routing of (A) glucose, (B) succinate, and (C) glycerol in E. coli central carbon metabolism. Growth rate of ETS variants on (D) succinate and (E) glycerol as carbon source before and after growth rate optimization by adaptive laboratory evolution. All laboratory evolutions were performed with three independently evolving lineages. The data from the final three flasks of the evolution experiments were used to show the growth rates of evolved strains. uXH: unevolved X protons per electron ETS variant, eXH: evolved X protons per electron ETS variant. The boxplot depicts the distribution of individual growth rate values for each strain under the specified growth condition. shows the post-ALE growth rate characterization of evolved strains to highlight the significant growth improvement. Acronyms- EMP: Embden-Meyerhof-Parnas Pathway, ED: Entner-Doudoroff Pathway, oxPPP: Oxidative Pentose Phosphate Pathway, TCA: Tricarboxylic Acid Cycle, g6p: D-Glucose-6-Phosphate, f6p: D-Fructose-6-Phosphate, 6 pg: 6-Phospho-D-Gluconate, g3p: Glyceraldehyde 3-Phosphate, pep: Phosphoenolpyruvate, pyr: Pyruvate, accoa: Acetyl-CoA, ru5p: Ribulose 5-Phosphate, r5p: Ribose 5-Phosphate, mal: Malate, glc: Glucose, succ: Succinate, glyc: Glycerol, WT: Wild Type, SMOS: Succinate Minimal Media Optimized WT Strain, GlyMOS: Glycerol Minimal Media Optimized WT Strain.

Article Snippet: Escherichia coli K12 MG1655 (ATCC 700926) was used as the wild-type strain.

Techniques: Variant Assay