ABSTRACT The gut microbiome has major roles in modulating host physiology. One such function is colonization resistance, or the ability of the microbial collective to protect the host

against enteric pathogens1,2,3, including enterohaemorrhagic _Escherichia coli_ (EHEC) serotype O157:H7, an attaching and effacing (AE) food-borne pathogen that causes severe

gastroenteritis, enterocolitis, bloody diarrhea and acute renal failure4,5 (haemolytic uremic syndrome). Although gut microorganisms can provide colonization resistance by outcompeting some

pathogens or modulating host defence provided by the gut barrier and intestinal immune cells6,7, this phenomenon remains poorly understood. Here, we show that activation of the

tryptophan-derived metabolites decreases expression of a host actin regulatory protein involved in _C. rodentium_ and EHEC attachment to the gut epithelium via formation of actin pedestals.

Our results reveal a noncanonical colonization resistance pathway against AE pathogens that features an unconventional role for DRD2 outside the nervous system in controlling actin

cytoskeletal organization in the gut epithelium. Our findings may inspire prophylactic and therapeutic approaches targeting DRD2 with dietary or pharmacological interventions to improve gut

health and treat gastrointestinal infections, which afflict millions globally. Access through your institution Buy or subscribe This is a preview of subscription content, access via your

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subscriptions * Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS VITAMIN B12 PRODUCED BY GUT BACTERIA MODULATES CHOLINERGIC SIGNALLING Article 02 January 2024

A COMMENSAL PROTOZOAN ATTENUATES _CLOSTRIDIOIDES DIFFICILE_ PATHOGENESIS IN MICE VIA ARGININE-ORNITHINE METABOLISM AND HOST INTESTINAL IMMUNE RESPONSE Article Open access 02 April 2024

_DUBOSIELLA NEWYORKENSIS_ MODULATES IMMUNE TOLERANCE IN COLITIS VIA THE L-LYSINE-ACTIVATED AHR-IDO1-KYN PATHWAY Article Open access 13 February 2024 DATA AVAILABILITY Next-generation

sequencing reads have been deposited at NCBI BioProject under accession number PRJNA1049399.  Source data are provided with this paper. CODE AVAILABILITY R script for statistical analysis,

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Microbiol._ 72, 5069–5072 (2006). ADS  CAS  PubMed  PubMed Central  Google Scholar  Download references ACKNOWLEDGEMENTS The authors thank the Arnold and Mabel Beckman Foundation (Beckman

Young Investigator Award to P.V.C.) and a President’s Council for Cornell Women Affinito-Stewart Grant (P.V.C.) for support. This work was supported in part by a grant from the National

Institutes of Health (NIH R35GM133501). J.F. was supported by a Cornell Institute of Host-Microbe Interactions and Disease (CIHMID) Postdoctoral Fellowship. Imaging data was acquired through

the Cornell Institute of Biotechnology BRC Imaging Facility (RRID:SCR_021741), with NYSTEM (C029155) and NIH (S10OD018516) funding for the shared Zeiss LSM 880 confocal/multiphoton

microscope. We thank the Weill Institute for Cell and Molecular Biology for additional resources and reagents. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Department of Microbiology,

Cornell University, Ithaca, NY, USA Samantha A. Scott * Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA Samantha A. Scott, Jingjing Fu & Pamela V. Chang *

Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA Pamela V. Chang * Cornell Center for Immunology, Cornell University, Ithaca, NY, USA Pamela V. Chang *

Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY, USA Pamela V. Chang Authors * Samantha A. Scott View author publications You can also search for

this author inPubMed Google Scholar * Jingjing Fu View author publications You can also search for this author inPubMed Google Scholar * Pamela V. Chang View author publications You can also

search for this author inPubMed Google Scholar CONTRIBUTIONS S.A.S. and P.V.C. conceptualized the study. S.A.S., J.F. and P.V.C. designed the experiments. J.F. performed the targeted

metabolomic studies. S.A.S. carried out all other studies and bioinformatic analyses. S.A.S., J.F. and P.V.C. wrote the manuscript. CORRESPONDING AUTHOR Correspondence to Pamela V. Chang.

ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing interests. PEER REVIEW PEER REVIEW INFORMATION _Nature_ thanks Vanessa Sperandio and the other, anonymous,

reviewer(s) for their contribution to the peer review of this work. ADDITIONAL INFORMATION PUBLISHER’S NOTE Springer Nature remains neutral with regard to jurisdictional claims in published

maps and institutional affiliations. EXTENDED DATA FIGURES AND TABLES EXTENDED DATA FIG. 1 THE TRP METABOLITES I3A, IPYA, AND IET PROTECT AGAINST _CITROBACTER RODENTIUM_ INFECTION IN MICE.

C57Bl/6 mice were pre-treated with antibiotics (ABX) for 7 d, followed by Trp metabolites, I3A (1000 mg/kg), IPyA (2900 mg/kg), or IEt (600 mg/kg) by oral gavage daily for 2 d. The mice were

then administered _C. rodentium_ (CR, oral gavage, 108 CFU) with continued ABX (except neomycin) and metabolite treatment for 10 d. Colon sections were stained with H&E. Shown are

representative images. Scale bar: 50 μm. Data are representative of at least 3 independent experiments, n = 10 mice per group. EXTENDED DATA FIG. 2 TRYPTOPHAN METABOLITES DO NOT AFFECT _C.

RODENTIUM_ AND EHEC GROWTH AND VIRULENCE IN VITRO. _C. rodentium_ (CR) (A–E) and EHEC O157:H7 (F–K) were cultured in the presence of I3A, IPyA, or IEt (100 μM). A, F, Growth was monitored by

measuring OD600 absorbance readings over 24 h. B, G, Cultures were plated after 24 h, and CFUs were counted. (C–E, H–K) Bacteria were cultured in low glucose DMEM under anaerobic (ana),

microaerophilic (micro), and aerobic (aero) conditions to activate locus of enterocyte effacement-pathogenicity island expression with I3A, IPyA, or IEt (100 μM). RNA was isolated after

cultures reached late-log phase (OD600 = 0.6–0.8), and cDNA was synthesized and analyzed by qPCR for the indicated genes. Relative expression of mRNA transcripts was normalized to the RNA

polymerase subunit alpha _rpoA_. Data are represented as the fold induction over control samples, bars = mean, error bars = standard deviation. Statistical analysis was performed using a

two-tailed Student’s t-test (A–B, F–G), or one-way ANOVA, followed by post-hoc Tukey multiple comparison test (C–E, H–K), n = 3 biological replicates examined over 3 independent experiments.

Source Data EXTENDED DATA FIG. 3 EFFECTS OF I3A, IPYA, AND IET DEPEND ON DOPAMINE RECEPTOR D2 (DRD2). A–B, Polarized Caco-2 monolayers were pre-treated with haloperidol (HAL, 10 μM) for 24 

h, followed by metabolites (I3A, IPyA, or IEt, 100 μM) for 2 d, and then infection with EHEC O157:H7 for 16 h. B, Representative images of pedestals (denoted by arrows) from Caco-2 cells

stained with DAPI and Alexa Fluor 647-phalloidin and imaged by confocal microscopy. Shown are maximum intensity z-projections. Scale bar: 5 μm. C, Western blot analysis of Caco-2 monolayers

to verify CRISPR/Cas9-mediated knockout (KO) of _Drd2_, _Drd3_, and _Drd4_. GAPDH is shown as a loading control. D–F, Caco-2 monolayers (WT vs. KO) were pre-treated with metabolites (I3A,

IPyA, or IEt, 100 μM) for 2 d and then infected with EHEC O157:H7 for 16 h. (A, D–F) Pedestal formation = # of pedestals per Caco-2 cell (HAL: I3A, n = 955; IPyA, n = 970; IEt, n = 1024;

_Drd3_ KO: I3A, n = 1089; IPyA, n = 1094; IEt, n = 1012; _Drd4_ KO: I3A, n = 1032; IPyA, n = 887; IEt, n = 1026; _Drd2_ KO: I3A, n = 1032; IPyA, n = 1026; IEt, n = 1073 cells examined over 3

independent experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers (lowest and highest values within 1.5 times IQR from the first and

third quartiles), and outliers beyond whiskers (dots), are shown. G-M, Caco-2 cells (WT vs KO) were pre-treated with metabolites (I3A, IPyA, or IEt, 100 μM) for 24 h and then infected with

EHEC O157:H7 for 12 h. Cell lysates were analyzed by Western blotting with the indicated antibodies. Source data are provided in Supplementary Fig. 9. (H, J, L, M) Densitometry was performed

using FIJI, bars = mean, error bars = standard deviation. Data are representative of at least 3 independent experiments, n = 3 biological replicates. Statistical analysis was performed

using one-way ANOVA, followed by post-hoc Tukey multiple comparison test. Source Data EXTENDED DATA FIG. 4 I3A, IPYA, AND IET ARE LIGANDS OF DOPAMINE RECEPTOR D2 (DRD2), WHICH SIGNALS VIA

GΑI, AND _DRD2_ IS KNOCKED OUT IN INTESTINAL EPITHELIAL CELLS IN _DRD2_FL/FL X VILLIN-CRE MICE FED TRP DIET DURING _C. RODENTIUM_ INFECTION. A, C–F, HEK 293 T cells overexpressing either

DRD2 and a split luciferase-based cAMP sensor (GloSensor) or B, DRD2-Tango and a β-arrestin-TEV fusion were incubated with dopamine (DA), I3A, IPyA, or IEt (1 mM each in A–B; concentrations

indicated in C–F) for 15 min (A, C–F) or 24 h (B), after which luminescence was measured to quantify ligand-induced (A) decrease in cAMP or (B) increase in β-arrestin recruitment. RLU =

relative luminescence units. EC50 and Kd values were calculated using GraphPad Prism. (G–H) _Drd2_fl/fl x Villin (Vil)-Cre or _Drd2_fl/fl mice were fed a conventional (2 g Trp/kg diet, ad

libitum) or Trp (42 g Trp/kg diet, ad libitum) diet for 7 d and then infected with _C. rodentium_ (CR, oral gavage, 108 CFU) with continued Trp feeding. Ten days post-infection, intestinal

cryosections were stained with DAPI and an anti-DRD2 antibody, followed by an anti-mouse Alexa Fluor 594 antibody. (G) Shown are representative z-slices. Scale bar: 20 μm. (H) Image

brightness was quantified using FIJI. Statistical analysis was performed using one-way ANOVA, followed by post-hoc Tukey multiple comparison test; bars = mean, error bars = standard

deviation, (A–F) n = 3 biological replicates and (G–H) n = 10 mice per group examined over 3 independent experiments. Source Data EXTENDED DATA FIG. 5 _DRD2_ IS KNOCKED OUT IN INTESTINAL

EPITHELIAL CELLS IN _DRD2_FL/FL X VILLIN-CRE MICE ADMINISTERED TRP METABOLITES DURING _C. RODENTIUM_ INFECTION. _Drd2_fl/fl x Villin (Vil)-Cre or _Drd2_fl/fl mice were treated with Trp

metabolites, I3A (1000 mg/kg), IPyA (2900 mg/kg), or IEt (600 mg/kg), by oral gavage daily for 2 d, and then infected with _C. rodentium_ (CR, oral gavage, 108 CFU) with continued metabolite

treatment. Ten days post-infection, intestinal cryosections were stained with DAPI and an anti-DRD2 antibody, followed by an anti-mouse Alexa Fluor 594 antibody. (A) Shown are

representative z-slices. Scale bar: 20 μm. (B–D) Image brightness was quantified using FIJI. Data are representative of at least 3 independent experiments, n = 10 mice per group, bars =

mean, error bars = standard deviation. Statistical analysis was performed using one-way ANOVA, followed by post-hoc Tukey multiple comparison test. Source Data EXTENDED DATA FIG. 6 EFFECTS

OF THE TRYPTOPHAN (TRP) DIET AND METABOLITES I3A, IPYA, AND IET IN PROTECTING AGAINST _C. RODENTIUM_ INFECTION DEPEND ON DOPAMINE RECEPTOR D2 (DRD2) IN INTESTINAL EPITHELIAL CELLS (IECS).

_Drd2_fl/fl x Villin (Vil)-Cre or _Drd2_fl/fl mice were fed a conventional (2 g Trp/kg diet, ad libitum) or Trp (42 g Trp/kg diet, ad libitum) diet for 7 d or Trp metabolites, I3A (1000 

mg/kg), IPyA (2900 mg/kg), or IEt (600 mg/kg), by oral gavage daily for 2 d, and then infected with _C. rodentium_ (CR, oral gavage, 108 CFU) with continued Trp feeding or metabolite

treatment. A–B, Bacterial load in (A) feces and (B) colon tissue was measured (A) every 1–2 d for 24 d post-infection and (B) at the peak of infection, 10 d post-infection. C–E, Colon

sections were stained with H&E and (C) blindly scored for submucosal edema (0-3), goblet cell depletion (0-3), epithelial hyperplasia (0-3), epithelial integrity (0-4), and neutrophil

and mononuclear cell infiltration (0-3). Data are expressed as the sum of these individual scores (0-16). See Methods for full description of scoring rubric. (D) Crypt heights were measured.

(E) Representative images. Scale bar: 50 μm. (F) Representative images of pedestals from Fig. 4a (denoted by arrows) stained with DAPI and Alexa Fluor 647-phalloidin and imaged by confocal

microscopy. Shown are maximum intensity z-projections. Scale bar: 5 μm. (G) Pedestal formation = # of pedestals per host cell (I3A, n = 1079; IPyA, n = 1027 cells examined over 3 independent

experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers (lowest and highest values within 1.5 times IQR from the first and third

quartiles), and outliers beyond whiskers (dots), are shown. H, I, Intestinal epithelial cells were isolated, and cell lysates were analyzed by Western blotting with the indicated antibodies.

Source data are provided in Supplementary Fig. 9. (I) Densitometry was performed using FIJI, n = 3 biological replicates. Data are representative of at least 3 independent experiments, n = 

10 mice per group, bars = mean, error bars = standard deviation. Statistical analysis was performed using the two-tailed Student’s t-test (A) or one-way ANOVA, followed by post-hoc Tukey

multiple comparison test: *p < 0.05, **p < 0.01, ***p < 0.001. Source Data EXTENDED DATA FIG. 7 SYNTHETIC DRD2 AGONIST PROTECTS AGAINST A MOUSE MODEL OF EHEC INFECTION USING _C.

RODENTIUM_, STRAIN DBS100, WHEREAS A DRD2 ANTAGONIST BLOCKS THE EFFECTS. A–I, _Drd2_fl/fl x Villin (Vil)-Cre or _Drd2_fl/fl mice were pre-treated with DRD2 agonist sumanirole (SUM, 4 mg/kg,

IP injection) daily for 2 d. J–R, _Drd2_fl/fl x Vil-Cre or _Drd2_fl/fl mice were pre-treated with DRD2 antagonist L-741,626 (1 mg/kg, IP injection) daily for 2 d, followed by conventional (2

 g Trp/kg diet, ad libitum) or Trp (42 g Trp/kg diet, ad libitum) diet for 7 d. A–R, The mice were then administered _C. rodentium_ (CR, oral gavage, 108 colony-forming units, CFU) with

continued (A–I) SUM treatment or (J–R) L-741,626 and Trp feeding. A, J Timeline for (A) SUM and (J) L-741,626 study. B–C, K–L, Bacterial load in (B, K) feces and (C, L) colon tissue was

measured (B, K) every 1–2 d for 10 d post-infection and (C, L) at the peak of infection, 10 d post-infection. (D–F, M–O) Colon sections were stained with H&E and (D, M) blindly scored

for submucosal edema (0-3), goblet cell depletion (0-3), epithelial hyperplasia (0-3), epithelial integrity (0-4), and neutrophil and mononuclear cell infiltration (0-3). Data are expressed

as the sum of these individual scores (0-16). See Methods for full description of scoring rubric. (E, N) Crypt heights were measured. (F, O) Representative images. Scale bar: 50 μm. (G, P)

Intestinal cryosections were stained with DAPI and Alexa Fluor 647-phalloidin. Pedestal formation = # of pedestals per host cell (SUM, n = 883; L-741,626, n = 1775 cells examined over 3

independent experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers (lowest and highest values within 1.5 times IQR from the first and

third quartiles), and outliers beyond whiskers (dots), are shown. H–I, Q–R, Intestinal epithelial cells were isolated, and cell lysates were analyzed by Western blotting with the indicated

antibodies. Source data are provided in Supplementary Fig. 9. (Q) Samples derive from the same experiment, and Western blots were processed in parallel. (I, R) Densitometry was performed

using FIJI, n = 3 biological replicates. Data are representative of at least 3 independent experiments, n = 10 mice per group, bars = mean, error bars = standard deviation. Statistical

analysis was performed using the two-tailed Student’s t-test (B, K) or one-way ANOVA, followed by post-hoc Tukey multiple comparison test: ***p < 0.001. Source Data EXTENDED DATA FIG. 8

EFFECTS OF TRP METABOLITES DO NOT DEPEND ON GΑI AND Β-ARRESTIN SIGNALING. Caco-2 cells were pre-treated with (A–D) Gαi inhibitor pertussis toxin (PTx, 100 ng/mL) for 18 h or (E–H) β-arrestin

inhibitor barbadin (100 μM) for 30 min, followed by Trp metabolite (I3A, IPyA, or IEt, 100 μM) for 24 h. The cells were then infected with EHEC (MOI 50) for 12 h, (A, E) fixed, and stained

with DAPI and Alexa Fluor 647-phalloidin. Pedestal formation = # of pedestals per Caco-2 cell (PTx: I3A, n = 994; IPyA, n = 916; IEt, n = 905; barbadin: I3A, n = 934; IPyA, n = 993; IEt, n =

 1087 cells examined over 3 independent experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers (lowest and highest values within 1.5 times

IQR from the first and third quartiles), and outliers beyond whiskers (dots), are shown. B–D, F–H, Alternatively, cells were lysed and analyzed by Western blotting with the indicated

antibodies. Source data are provided in Supplementary Fig. 9. (C–D, G–H) Densitometry was performed using FIJI. Data are representative of at least 3 independent experiments, n = 3

biological replicates, bars = mean, error bars = standard deviation. Statistical analysis was performed using one-way ANOVA, followed by post-hoc Tukey multiple comparison test. Source Data

EXTENDED DATA FIG. 9 EFFECTS OF TRP METABOLITES DEPEND ON GΒΓ AND PHOSPHOLIPASE C. Caco-2 cells were pre-treated with (A–H) Gβγ inhibitor gallein (10 μM) for 30 min or (I–P) PLC inhibitor

U-73122 (10 μM) for 30 min, followed by Trp metabolite (I3A, IPyA, or IEt, 100 μM) for 24 h. The cells were then infected with EHEC (MOI 50) for 12 h, (A, I) fixed, and stained with DAPI and

Alexa Fluor 647-phalloidin. Pedestal formation = # of pedestals per Caco-2 cell (gallein: I3A, n = 944; IPyA, n = 1073; IEt, n = 905; U-73122: I3A, n = 977; IPyA, n = 1068; IEt, n = 1075

cells examined over 3 independent experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers (lowest and highest values within 1.5 times IQR

from the first and third quartiles), and outliers beyond whiskers (dots), are shown. B–H, J–P, Alternatively, cells were lysed and analyzed by Western blotting with the indicated antibodies.

Source data are provided in Supplementary Fig. 9. (C, E, G, H, K, M, O, P) Densitometry was performed using FIJI. Data are representative of at least 3 independent experiments, n = 3

biological replicates, bars = mean, error bars = standard deviation. Statistical analysis was performed using one-way ANOVA, followed by post-hoc Tukey multiple comparison test. Source Data

EXTENDED DATA FIG. 10 EFFECTS OF TRP METABOLITES DEPEND ON PROTEIN KINASE C (PKC). Caco-2 cells were pre-treated with pan-PKC inhibitor sotrastaurin (Sotra, 5 μM) for 30 min, followed by Trp

metabolite (I3A, IPyA, or IEt, 100 μM) for 24 h. The cells were then infected with EHEC (MOI 50) for 12 h, (A) fixed, and stained with DAPI and Alexa Fluor 647-phalloidin. Pedestal

formation = # of pedestals per Caco-2 cell (I3A, n = 912; IPyA, n = 1138; IEt, n = 1086 cells examined over 3 independent experiments). For box plots, interquartile ranges (IQRs, boxes),

median values (line within box), whiskers (lowest and highest values within 1.5 times IQR from the first and third quartiles), and outliers beyond whiskers (dots), are shown. B–F,

Alternatively, cells were lysed and analyzed by Western blotting with the indicated antibodies. Source data are provided in Supplementary Fig. 9. (C, E, F) Densitometry was performed using

FIJI. Data are representative of at least 3 independent experiments, n = 3 biological replicates, bars = mean, error bars = standard deviation. Statistical analysis was performed using

one-way ANOVA, followed by post-hoc Tukey multiple comparison test. Source Data EXTENDED DATA FIG. 11 EFFECTS OF TRP METABOLITES DEPEND ON PROTEIN KINASE C (PKC)-Θ. Caco-2 cells were

pre-treated with (A–F) isoform-selective PKC-θ inhibitor (PKCθi, 5 μM) for 24 h, or (G–L) PKC-θ was knocked down using two different siRNA duplexes (1 and 2) or a negative control siRNA

duplex (C), followed by Trp metabolite (I3A, IPyA, or IEt, 100 μM) for 24 h. The cells were then infected with EHEC (MOI 50) for 12 h, (A, G) fixed, and stained with DAPI and Alexa Fluor

647-phalloidin. Pedestal formation = # of pedestals per Caco-2 cell (PKCθi: I3A, n = 1063; IPyA, n = 1005; IEt, n = 1033; siRNA: I3A, n = 1680; IPyA, n = 1462; IEt, n = 1502 cells examined

over 3 independent experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers (lowest and highest values within 1.5 times IQR from the first

and third quartiles), and outliers beyond whiskers (dots), are shown. B–F, H–L, Alternatively, cells were lysed and analyzed by Western blotting with the indicated antibodies. Source data

are provided in Supplementary Fig. 9. (C, E, F, I, K, L) Densitometry was performed using FIJI. Data are representative of at least 3 independent experiments, n = 3 biological replicates,

bars = mean, error bars = standard deviation. Statistical analysis was performed using one-way ANOVA, followed by post-hoc Tukey multiple comparison test. Source Data EXTENDED DATA FIG. 12

EFFECTS OF TRP METABOLITES DEPEND ON PROTEASOMAL DEGRADATION. Caco-2 cells were pre-treated with proteasomal inhibitor MG-132 (10 μM) for 1 h, followed by Trp metabolite (I3A, IPyA, or IEt,

100 μM) for 24 h. The cells were then infected with EHEC (MOI 50) for 12 h, (A) fixed, and stained with DAPI and Alexa Fluor 647-phalloidin. Pedestal formation = # of pedestals per Caco-2

cell (I3A, n = 1079; IPyA, n = 999; IEt, n = 911 cells examined over 3 independent experiments). For box plots, interquartile ranges (IQRs, boxes), median values (line within box), whiskers

(lowest and highest values within 1.5 times IQR from the first and third quartiles), and outliers beyond whiskers (dots), are shown. B–H, Alternatively, cells were lysed and analyzed by

Western blotting with the indicated antibodies. Source data are provided in Supplementary Fig. 9. (C, E, G, H) Densitometry was performed using FIJI. Data are representative of at least 3

independent experiments, n = 3 biological replicates, bars = mean, error bars = standard deviation. Statistical analysis was performed using one-way ANOVA, followed by post-hoc Tukey

multiple comparison test. Source Data SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION Supplementary Figs. 1–9 REPORTING SUMMARY SOURCE DATA SUPPLEMENTARY FIG. 1 SOURCE DATA SUPPLEMENTARY

FIG. 2 SOURCE DATA SUPPLEMENTARY FIG. 3 SOURCE DATA SUPPLEMENTARY FIG. 4 SOURCE DATA SUPPLEMENTARY FIG. 5 SOURCE DATA SUPPLEMENTARY FIG. 6 SOURCE DATA SUPPLEMENTARY FIG. 7 SOURCE DATA

SUPPLEMENTARY FIG. 8 SOURCE DATA SOURCE DATA FIG. 1 SOURCE DATA FIG. 2 SOURCE DATA FIG. 3 SOURCE DATA FIG. 4 SOURCE DATA EXTENDED DATA FIG. 2 SOURCE DATA EXTENDED DATA FIG. 3 SOURCE DATA

EXTENDED DATA FIG. 4 SOURCE DATA EXTENDED DATA FIG. 5 SOURCE DATA EXTENDED DATA FIG. 6 SOURCE DATA EXTENDED DATA FIG. 7 SOURCE DATA EXTENDED DATA FIG. 8 SOURCE DATA EXTENDED DATA FIG. 9

SOURCE DATA EXTENDED DATA FIG. 10 SOURCE DATA EXTENDED DATA FIG. 11 SOURCE DATA EXTENDED DATA FIG. 12 RIGHTS AND PERMISSIONS Springer Nature or its licensor (e.g. a society or other partner)

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receptor D2 confers colonization resistance via microbial metabolites. _Nature_ 628, 180–185 (2024). https://doi.org/10.1038/s41586-024-07179-5 Download citation * Received: 13 September

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