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Obesity impairs gut repair via AFABP-mediated iron overload in intestinal stem cells

Nature Metabolism volume 8, pages 74–95 (2026)Cite this article

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Abstract

Obesity impairs the function of multiple organs, but its effect on gut regeneration remains poorly defined. Here, we show that adipocyte fatty acid-binding protein (AFABP), an adipokine involved in fatty acid transport, impedes intestinal repair by disrupting iron homeostasis in intestinal stem cells (ISCs). Mechanistically, elevated AFABP secretion in obesity binds to plasma transferrin, leading to iron accumulation in ISCs. This accumulation disrupts peroxisome-mediated ISC differentiation, which is essential for intestinal repair following injury. Notably, AFABP overexpression in adipocytes of lean mice impedes ISC differentiation and gut repair. Conversely, AFABP depletion or the administration of AFABP inhibitors, iron chelators or peroxisome activators effectively mitigates colitis in obese animals. Overall, our findings reveal a mechanistic link between obesity and intestinal repair, and identify the adipose–gut axis as a therapeutic target for obesity-associated intestinal disorders.

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Fig. 1: Obesity impairs intestinal epithelial regeneration and ISC differentiation.
Fig. 2: AFABP underlies the obesity-induced hindrance of intestinal epithelial regeneration.
Fig. 3: AFABP overexpression in adipocytes impedes ISC differentiation and intestinal epithelial regeneration.
Fig. 4: AFABP depletion in adipocytes improves intestinal epithelial regeneration in obese animals.
Fig. 5: AFABP perturbs various signalling pathways associated with the ISC differentiation during intestinal epithelial repair.
Fig. 6: AFABP interacts with TSF to hinder ISC differentiation and gut regeneration in Drosophila.
Fig. 7: AFABP interacts with TSF to hinder ISC differentiation and gut regeneration.
Fig. 8: AFABP prevents ISC differentiation following intestinal injury by modulating the iron–PPAR–peroxisome axis in ISCs.

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Data availability

RNA-seq data have been deposited in the Sequence Read Archive BioProject under accession number PRJNA1141152 and the results are provided in Supplementary Tables 1 and 3. Mass spectrometry proteomics data have been deposited in the Integrated Proteome Resources (iProX) under accession number IPX0009375000, and the results are provided in Supplementary Table 5. Mendelian randomization data using the UK Biobank cohort are available from the online GWAS Catalog and the accession codes are provided in Supplementary Table 8. The datasets generated and/or analysed during this study are available without restrictions from the corresponding author. The full, unedited gel images from the western blot experiment are now available for public review on the Mendeley Data platform via https://data.mendeley.com/datasets/5zkmndssff/2/. Source data are provided with this paper.

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Acknowledgements

We thank BDSC, VDRC and Tsinghua Fly Center for fly strains and DSHB for antibodies. This work was supported by the National Key R&D Program of China (2020YFA0803602), the National Natural Science Foundation of China (32470879 and 92157109, to Haiyang Chen), Sichuan Science and Technology Program: Sichuan Provincial Natural Science Foundation (grant nos. 2025ZNSFSC0720, to Haiyang Chen; 2024NSFSC1695, to Q.W.), Noncommunicable Chronic Diseases-National Science and Technology Major Project (2023ZD0506800, to Haiyang Chen), the 1·3·5 project for disciplines of excellence, West China Hospital, Sichuan University (ZYYC20024, to Haiyang Chen), Natural Science Foundation of Sichuan Province (grant no. 2023NSFSC0664, China, to Y.C.), the 1·3·5 projects for Artificial Intelligence, West China Hospital, Sichuan University (ZYAI24024, to Y.C.), China Postdoctoral Science Foundation (2023TQ0225, to Q.W.) and Postdoctoral Fellowship Program of China Postdoctoral Science Foundation (GZC20231818, to Q.W.). We sincerely appreciate the assistance of L. Chai, Y. Li and X. Xu from the Core Facilities at West China Hospital, Sichuan University. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

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Author notes

  1. These authors contributed equally: Zhiming Liu, Yi Chen, Jinhua Yan, Yu Yuan, Qianyi Wan, Rui Zhao.

Authors and Affiliations

  1. West China Centre of Excellence for Pancreatitis, and Laboratory of Metabolism and Aging, Frontiers Science Center for Disease-related Molecular Network, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China

    Zhiming Liu, Jinhua Yan, Yu Yuan, Qianyi Wan, Fang Fu, Xinxin Fan, Yawen Deng, Xiaoxin Guo, Haiou Chen, Xingzhu Liu, Jinbao Ye & Haiyang Chen

  2. Division of Gastrointestinal Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, China

    Yi Chen, Qianyi Wan & Rui Zhao

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Contributions

Conceptualization: Haiyang Chen and Z.L.; Methodology: Z.L., Y.Y., Y.C, F.F., Y.D., J. Yan, X.F. and R.Z.; Investigation: Z.L., J. Yan, Y.Y., Q.W., X.G. and R.Z.; Visualization: Z.L., Y.Y., X.G. and J. Yan; Writing—original draft: Z.L., Q.W., J. Yan, Y.Y. and Haiyang Chen.; Writing—review and editing: L.Z., Q.W., Y.Y., J. Yan, F.F., X.F., Y.C., Haiou Chen, X.L., J. Ye and Haiyang Chen; Funding acquisition: Haiyang Chen; Resources: Haiyang Chen and Y.C.; Supervision: Haiyang Chen.

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Correspondence to Haiyang Chen.

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Extended data

Extended Data Fig. 1 Obesity impairs intestinal epithelial regeneration and ISC differentiation in mice.

a, Mendelian randomization forest plot showing causal associations between adiposity-related traits and impaired intestinal repair. Hazard ratios (HR) and 95 % confidence intervals (CI) were estimated using inverse-variance weighted meta-analysis of SNP-specific Wald ratios. The solid squares represent point estimates. Horizontal lines indicate 95 % CIs. A HR > 1 implies increased risk of poor repair. BMI and waistline showed significant positive causal effects (CI excludes 1), whereas age and sex exhibited no significant association. b, Monitoring the body weight changes in wild-type mice administered a high-fat diet [HFD (Obesity)] (n = 10 mice) versus a normal chow diet [control, NCD (NW)] (n = 10 mice) over 12 weeks. c-e, Fat pad weight of NW and Obesity group over 12 weeks (n = 10 mice for each group). f, Photographic images and Hematoxylin/Eosin (H&E) staining of fat pads obtained from NW and Obesity group over 12 weeks. g, h, Colon length (g) and Histology score (h) from obese mice and normal-weight mice before dextran sulfate sodiume (DSS). n = 5 mice for each group. i, Body weight changes of ob/+ (control) and leptin-deficient mice (ob/ob) fed on NCD over 12 weeks (n = 10 mice for each group). j, H&E staining of ileum from ob/+ and ob/ob mice before 12 Gy X-irradiation (0 dpi). Days Post Irradiation (dpi) (n = 3 mice/group). 0 dpi: Baseline before radiation exposure, used as a reference. Images are representative of three independent experiments yielding similar results. k, l, Histology staining (k) and numbers of intact crypts (n = 20 fields of view from 5 mice) (l) of the colon from 7 dpi ob/+ and ob/ob mice were shown. 7 dpi: Advanced repair phase with inflammation subsided and near-complete tissue regeneration. Nuclei stained with DAPI are shown in blue. Scale bars represent 100 μm (f and j-k). mean +/- SDs, except indicate mean +/- SEMs (b and i). Significance: ns (not statistically significant) signifies p > 0.05. Unpaired two-tailed Student’s t-tests for (b-e, l). Experiments were performed three times. one-way ANOVA with Dunnett multiple comparison test for others.

Source data

Extended Data Fig. 2 Obesity impairs intestinal epithelial regeneration and ISC differentiation in Drosophila and intestinal organoid.

a, Diagram of Drosophila intestinal stem cell differentiation model. b, Representative images of midguts with esg-GFP (green) and Delta (Dl+) cells (ISCs, red) staining. NCD as control. c, d, Quantification of the ratio of esg-GFP+ cells to DAPI+ cells (c) Dl+ cells to DAPI+ cells (d). n = 15 midguts each group. e, Representative images of midguts with Armadillo (Arm, indicates cell barrier, red) staining. Images are representative of three independent experiments yielding similar results. f, g, DAPI-stained midguts (f) and midgut length quantification (g) n = 11 midguts each group. h, i, pH3+ number per gut (h) and ratio of NRE-lacZ+ cells to esg-GFP+ cells (i). n = 15, 15, 15, 15, 15, 14, 15,15 midguts in (h), n = 15 midguts in (i). j, Representative F/O clone images showing GFP-marked (green) and Pdm1 (red, labeling preECs and mature ECs). F/O: Flip-out lineage-tracing. k, Representative F/O clone images showing GFP-marked clones (green) and Pros (red, labeling EEs). l, m, left: Quantification of cell counts (Pdm1+ ECs; Pros+ EEs) within each clone (l). Right: Percentage of specific cell types relative to total clone cells (DAPI+) (m) n = 40 clones from 20 flies each group. n, o, Representative images (n) and quantification (o) of the buds from humans with obesity and normal weight (NW) n = 64 organoids. p, q, Representative images (p) and quantification number (q) of Lysozyme (green) staining from human jejunum organoids. n = 15 organoids. r, s, Representative immunofluorescence (r) images and quantification (s) of human jejunum organoids with Mucin2 (Muc2) staining. n = 10 organoids. t, Representative images of human jejunum organoids with Alkaline Phosphatase (AP) staining. u, mRNA expression of human jejunum organoids. n = 3 independent experiments. v, Schematic representation of the lineage tracing model using Lgr5-EGFP-IRES-CreERT2 mice crossed with CAGZsGreen reporter mice. Created by Figdraw (www.figdraw.com). Scale bars represent 10 μm (j, k)20 μm (b, e) 1 mm (f), 500 μm (n), and 200 μm (p, r, t). Error bars indicate mean +/- SDs, ns signifies p > 0.05. Unpaired two-tailed Student’s t-tests was used. Experiments were performed three times. NCD as control Additional data are provided in Tables S4 and S6.

Source data

Extended Data Fig. 3 AFABP underlies the obesity-induced hindrance of intestinal epithelial regeneration.

a-d, Quantification of the ratio of esg-GFP+ cells to DAPI+ cells (a), Dl+ cells to DAPI+ cells (b), the number of pH3+ cells per gut (c), and NRE-lacZ+ cells to esg-GFP+ cells (d). n = 15 midguts each group (c). LUCRNAi as control. e-g, Quantification of the ratio of esg-GFP+ cells to DAPI+ cells (e), Dl+ cells to DAPI+ cells (f), and NRE-lacZ+ cells to esg-GFP+ cells (g) n = 15 midguts each group. LUCRNAi as control. h, mRNA expression of EC maturation-associated genes. n = 3 independent experiments. i-l, Quantification of the ratio of NRE+ cells to esg-GFP+ cells (i), esg-GFP+ cells to DAPI+ cells (j), Dl+ cells to DAPI+ cells (k), and the number of pH3+ cells per gut (l) n = 15 midguts each group. LUCRNAi + NCD as control. m, Relative mRNA expression of COPI genes. n = 3 independent experiments. LUCRNAi as control. n, A volcano plot illustrating the differential expression of genes from mesenteric adipose tissue of obesity and NW mice. o, A bar chart depicting upregulated genes with red bars and downregulated genes with green bars of obesity and NW mice. p, Relative mRNA expression of dFabp genes. n = 3 independent experiments. LUCRNAi as control. q-t, Quantification of the ratio of esg-GFP+ cells to DAPI+ cells (q), Dl+ cells to DAPI+ cells (r), NRE-lacZ+ cells to esg-GFP+ cells (s) (n = 11-15 midguts each group) and the number of pH3+ cells per gut (n = 15 midguts) (t). u, The AlphaFold structural prediction for both the fruit fly dFABP protein and its human counterpart, AFABP. Error bars indicate mean +/- SDs, ns (not statistically significant) signifies p > 0.05. LUCRNAi as control. Experiments were performed three times. One-way ANOVA with Dunnett multiple comparison test for (a-l, p). Unpaired two-tailed Student’s t-tests for (m, q-t). Additional data are provided in Tables S1, S,4 and S6.

Source data

Extended Data Fig. 4 AFABP overexpression in adipocytes impedes ISC differentiation and intestinal epithelial regeneration.

a, b, Number of pH3+ cells per gut (a) and ratio of Dl+ cells to DAPI+ cells (b). n = 15 midguts/group. LUCOE as control. c-e, Ratio of esg-GFP+ cells to DAPI+ cells (c), Dl+ cells to DAPI+ cells (d), and NRE-lacZ+ cells to esg-GFP+ cells (e). n = 15,18 midguts/group. LUCOE as control. f, g, Relative mRNA expression of dFabp and hAFABP driven with Cgts (f) and Cg-LexA (g). n = 3 independent experiments. h, Representative image of excretion. LUCOE or mRFPOE as control and images are representative of three independent experiments yielding similar results. i, Images of Smurf flies: non-Smurf (dye in gut) vs Smurf+ (dye throughout body). Three independent experiments were performed. j, k, Bromophenol blue-stained Drosophila midgut (j) and ratio of homeostasis state (n = 6, 5 independent experiments) (k). l-o, Survival rate of flies with indicated genotypes under 5 μg/ml BLM treatment. n = 3 independent experiments and represent median survival and 95% confidence interval. p-r, Representative images (p) and survival rate, n = 3 independent experiments (q) and buds’ number (n = 40 organoids/group) (r) of human organoids treated with PBS or hAFABP, Representative images and Muc2 staining quantification (n = 10 organoids each group). t, u, Representative images of human organoids with lysozyme (green)(t) and AP staining (u). v, Number of Lysozyme+ cells/organoid (n = 15 organoids). w, mRNA expression of indicated genes from human organoid. n = 3 independent experiments. x-y, Relative mRNA expression of AFABP (x, n = 3 independent experiments) and representative images of colon H&E staining from AAV-eGFP (eGFPAOE) or AAV-AFABP (AFABPAOE) mice (y). z, Histology score from eGFPAOE and AFABPAOE mice REC-2D (n = 5 mice each group). Scale bars represent 500 mm (h-j, p), 200 mm (s, t, u), and 100 μm (y). Error bars indicate mean +/-SDs. Survival curves were analyzed using the log-rank (Mantel-Cox) test and represent median survival and 95% confidence interval, ns signifies p > 0.05. Unpaired two-tailed Student’s t-tests for (c, d, e, f, g, k, q, r, s, v, w, x, z). n = 3 independent experiments. One-way ANOVA with Dunnett multiple comparison test for others.

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Extended Data Fig. 5 AFABP depletion in adipocytes improves intestinal epithelial regeneration in obese animals.

a, Survival rate of female flies without BLM of indicated genotypes under NCD treatment. Three independent experiments were conducted. n = 100 flies. LUCRNAi as control. b, Survival rate of female flies with 5 μg/ml BLM of indicated genotypes under HFD or NCD treatment. n = x independent experiments. Three independent experiments were conducted. n = 83, 87, 66, 80 flies. LUCRNAi as control. c-e, Ratio of Smurf (+) files (n = 5, 6 independent experiments) (c), the ratio of homeostasis state (n = 5, 5 independent experiments) (d), and deposits (n = 10, 12 fields of view) (e). f-i, Mean midgut length (n = 16, 18 midguts for each group) (f), the ratio of Smurf (+) files (n = 5, 6 independent experiments) (g), deposits (n = 18,12 fields of view) (h), and ratio of homeostasis state (n = 5, 5 independent experiments) (i). j-l, Ratio of NRE-lacZ+ cells to esg-GFP+ cells (j), esg-GFP+ cells to DAPI+ cells (k), and Dl+ cells to DAPI+ cells (l) (n = 12 midguts each group). m, Results of the ELISA for AFABP in serum (n = 6 mice each group). n, the mRNA expression of AFABP in adipose (n = 4 mice each group). o, p Representative images (o) and survival rate (p) (n = 3 independent experiments) of jejunum organoids from mice. q, Quantification of the buds per organoid from Normal weight AFABPfl/fl mice (NW-WT), obese AFABPfl/fl mice (OB-WT), and obese AFABPAKO mice (OB-AFABPAKO) (n = 39 organoids each group). r, Representative images of jejunum organoids with Lysozyme (upper, green) and AP staining (lower) from mice. s, Quantification of the Lysozyme+ cells per organoid (n = 15 organoids each group). t, mRNA expression of indicated genes from jejunum organoids from mice. n = 3 independent experiments. Scale bars represent 200 μm (o, r). Error bars indicate mean +/- SDs. Survival curves were analyzed using the log-rank (Mantel-Cox) test. P-values were calculated as indicators of statistical significance, ns signifies p > 0.05. One-way ANOVA with Dunnett multiple comparison test for (j-l, p, q, s, t). Three independent experiments were performed. Unpaired two-tailed t-tests for other results. Additional data are provided in Tables S4 and S6.

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Extended Data Fig. 6 AFABP perturbs various signaling pathways associated with the ISC differentiation during intestinal epithelial repair.

a, Heatmap of all gene expression in the different groups. b, KEGG pathway enrichment analysis of differentially expressed genes between the OB-WT and NW-WT groups. c, Heatmap showing the expression levels of Wnt, Notch, TGF-β, and PI3K-AKT target genes in intestinal crypts from NW-WT, OB-AFABPAKO, and OB-WT groups. d, e, Relative mRNA of Wnt signaling pathways (Ctnnb1) (d) or Notch pathways (Notch1) (e). Temporal expression profiles normalized to NW-WT at DSS-0D (set as 1). Comparative analyses were conducted between NW-WT and OB-WT, as well as between Obese mice with OB- AFABPAKO and OB-WT. n = 3 independent experiments. f-i, Western blot representative images (f) and quantification of β-catenin (Wnt signaling) (g, h) and Notch intracellular domain (NICD) (i) dynamics in: NW-WT; OB-WT; OB-AFABPAKO. Temporal expression profiles normalized to NW-WT at DSS-0D (set as 1): NW-WT exhibits oscillatory β-catenin (Wnt) and Notch dynamic balance；OB-AFABPAKO restores the oscillatory pattern. n = 3 independent experiments. j, AP staining showed organoids with hAFABP addition exhibited a reduction in enterocyte differentiation and could be rescued by IWP-2 (an inhibitor of Wnt signaling), with DMSO as control. Three independent experiments were performed. k, Relative mRNA expression of indicated genes in human intestinal organoids of indicated treatment (n = 3 independent experiments). Scale bars represent 200 μm (j). Error bars indicate mean +/- SDs. P-values were calculated as indicators of statistical significance, ns signifies p > 0.05. One-way ANOVA with Dunnett multiple comparison test for (d, e, g, h, i, k). Additional data are provided in Tables S3 and S4.

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Extended Data Fig. 7 AFABP interacts with Transferrin to hinder ISC differentiation and gut regeneration in Drosophila.

a, A diagram outlining the process of using immunoprecipitation coupled with mass spectrometry (IP-MS) to uncover interaction partners of hAFABP in hemolymph. Created by Figdraw (www.figdraw.com). b, DMFOLD, a DeepMSA2 based protein folding model, indicates a strong binding affinity between hAFABP and hTSF1. c-f, Ratio of Smurf (+) files (c, n = 6, 7 independent experiments), deposits (d, n = 20, 23 fields of view for each group), ratio of homeostasis state (e, n = 6, 6 independent experiments), and midgut length (f, n = 21, 20 midguts respectively) from flies fed NCD of indicated genotypes indicated boosting dTSF1 expression in Drosophila fat bodies enhanced intestinal functions in hAFABP-overexpressing flies (control) after gut injury (REC-3D). Overexpression of dTSF1 lines (dTSF1OE) was used. g-i, Ratio of NRE-lacZ+ cells to esg-GFP+ cells (g, n = 11-12 midguts for each group), esg-GFP+ cells to DAPI+ cells (h, n = 12 midguts for each group), and Dl+ cells to DAPI+ cells (i, n = 12 midguts for each group) from flies with indicated treatments and genotypes. RNAi line against dTSF1 (dTSF1RNAi) was used. LUCRNAi as control. j, Relative mRNA expression of dTsf1 genes from indicated genotypes (LUCRNAi, dTSF1RNAi), n = 3 independent experiments. LUCRNAi as control. k, Relative mRNA expression of dTsf1 genes from indicated genotypes (LUCOE and dTSF1OE), n = 3 independent experiments. l, Ratio of esg-GFP+ cells to DAPI+ cells from HFD-induced obese flies treated with vehicle, BPS, DFO, or FAC. Flies treated with NCD only were used as a control (n = 12, 15, 13, 14, 19 midguts respectively). BPS, DFO (two iron chelators), and FAC (an iron supplement) were used. m, Heatmap depicting varied expression patterns of key genes regulating iron homeostasis from NW-WT, OB-AFABPAKO, and OB-WT groups. n, Atomic Absorption Spectroscopy (AAS) analysis of iron content from colonic crypts of indicated treatments and genotypes mice (n = 4 mice). NW-WT as control. Error bars indicate mean +/- SDs. Significance: ns signifies p > 0.05. Unpaired two-tailed Student’s t-tests for (c-f, j, k), one-way ANOVA with Dunnett multiple comparison test for other results. Three independent experiments were performed.

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Extended Data Fig. 8 AFABP interacts with Transferrin to hinder ISC differentiation and gut regeneration in mice.

a, b, Western blot representative images (a) and quantification (b) of FTH1 from human organoid (n = 3 independent experiments). c, Representative images of buds of human jejunum organoids treated with Vehicle (PBS), hAFABP, or hAFABP together with DFO. d, Quantification of buds of human jejunum organoids treated with PBS, hAFABP, or hAFABP together with DFO. n = 40 organoids. e, f, Representative images (e) and quantification (f) of jejunum organoids with Lysozyme from human jejunum organoids. n = 15 organoids. g, Representative images of jejunum organoids with AP staining from human jejunum organoids from 3 independent experiments. h, Relative mRNA expression of indicated genes in human intestinal organoids of indicated treatment (n = 3 independent experiments). i, Quantification of survival rate of human jejunum organoids. n = 3 independent experiments, j, Prussian blue staining of liver and spleen sections revealed elevated iron deposition in NW-AFABPAOE mice compared to NW- eGFPAOE controls. k, l, serum non-transferrin-bound iron (NTBI) levels quantified by colorimetric assay (n = 5 mice for each group) (k). NW-AFABPAOE mice exhibited significantly elevated NTBI versus NW-eGFPAOE, indicating systemic iron overload. Measurement of total iron content shows increased levels in NW-AFABPAOE compared to NW- eGFPAOE (n = 3 mice for each group) (l). Scale bars represent 500 μm (c), 200 μm (e, g), 100 μm (j). Error bars indicate mean +/- SDs. Significance: ns signifies p > 0.05. Unpaired two-tailed Student’s t-tests for (b, k, l), one-way ANOVA with Dunnett multiple comparison test for other results. Additional data are provided in Table S4.

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Extended Data Fig. 9 AFABP prevents ISC differentiation following intestinal injury by modulating the iron-PPAR-peroxisome axis in ISCs.

a, Representative image of midguts with esg-GFP (green) and Eip75B-mcherry (red) staining from flies of indicated treatments and genotypes after gut injury (Injury-1D) from 3 independent experiments. b, Quantification of fluorescence intensity of Eip75B-mCherry per esg+ cells from flies with indicated treatments and genotypes after gut injury (Injury-1D) (n = 99 esg+ cells for each group). c, PPI network analysis revealed enriched interactions involving iron transport, peroxisomal biogenesis, Wnt, and Notch pathways, underscoring their notable crosstalk. d, Representative images of midguts with GFP-SKL (green) staining from flies with indicated treatment [NCD + vehicle (water), NCD + FAC, HFD + vehicle, or HFD + DFO] after gut injury (injury-0D and REC-1D) from 3 independent experiments. e, Quantification of the fluorescence intensity of GFP-SKL per esg+ cells in (b) (n = 100 esg+ cells for each group). f, Representative images of midguts with Eip75B-mCherry staining from flies of indicated treatments and genotypes with gut injury (injury-0D and REC-1D) from 3 independent experiments. g, Quantification of the fluorescence intensity of Eip75B-mCherry per esg+ cells in (f) (n = 158, 119, 249, 127 esg+ cells respectively). h, Immunofluorescence and quantification of GFP-SKL staining in midguts from NCD-fed flies of control (n = 135 esg+ cells from 20 Drosophila midguts) and hAFABPOE (n = 143 esg+ cells from 20 Drosophila midguts) after gut injury (REC-1D). i, Immunofluorescence and quantification of Rab7-GFP staining in midguts from NCD-fed flies from control (n = 113 esg+ cells) and hAFABPOE (n = 131 esg+ cells) after gut injury (REC-1D). Results were from 3 independent experiments. Nuclei stained with DAPI are shown in blue. Scale bars represent 20 μm (a, d, h, i) and 10 μm (f). Error bars indicate mean +/- SDs. Unpaired two-tailed Student’s t-tests for (h, i), one-way ANOVA with Dunnett multiple comparison test for other results. Significance: ns signifies p > 0.05. Additional data are provided in Table S6.

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Extended Data Fig. 10 Enhanced Peroxisomal Function Promotes Intestinal Regeneration in AFABP-Overexpressing Drosophila.

a, Representative images of midguts with NRE-lacZ (red) and esg-GFP (green) staining from 3 independent experiments. b, Quantification of the ratio of NRE-lacZ+ cells to esg-GFP+ cells (n = 14 midguts for each group). c-g, Quantification of the ratio of esg-GFP+ cells to DAPI+ cells (c and e), Dl+ cells to DAPI+ cells (d and f), and NRE-lacZ+ cells to esg-GFP+ cells (g) (n n=numbers of midguts for each group as indicated in figures). h-m, Quantification of deposits (h and m), the ratio of homeostasis state (i and k), and the ratio of Smurf (+) files (j and l). (h, n = 16, 20 fields of view for each group), (i, n = 6 midguts respectively), (j, n = 5, 7 independent experiments), (k, n = 7, 5, 8, 5 independent experiments), (l, n = 5, 4, 5, 6 independent experiments), (m, n = 25, 14, 17, 14 fields of view for each group). n-p, Quantification of the ratio of esg-GFP+ cells to DAPI+ cells (n), NRE-lacZ+ cells to esg-GFP+ cells (o) and Dl+ cells to DAPI+ cells (p) (n = 20, 26, 23 midguts for each group respectively). NaPB, pioglitazone (two agents that enhance peroxisome proliferation through PEX11 stimulation) were used. q-s, Quantification of midgut length (n = 24, 26, 23 midguts respetively) (q), deposits (n = 20, 22, 21fields of view) (r), and the ratio of Smurf (+) files (n = 6 independent experiments) (s). t, Relative mRNA expression of pex11ab genes from indicated genotypes (n = 3 independent experiments). u, Relative mRNA expression of Eip75b genes from indicated genotypes (n = 3 independent experiments). v, w, Western blot representative images (v) and quantification (w) of PPARα after injury in mice, n = 3 independent experiments. x-aa, Relative mRNA expression of Pparα (x) and its target genes (y–aa) after injury in mice, n = 3 mice. Nuclei stained with DAPI are shown in blue. Scale bars represent 20 μm (a). Error bars indicate mean +/- SDs. Unpaired two-tailed Student’s t-tests for (h-j, t, u), one-way ANOVA with Dunnett multiple comparison test for other results. Significance: ns signifies p > 0.05. Additional data are provided in Tables S4 and S6.

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Supplementary information

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List of changed genes in adipose RNA-seq and list of gene counts from adipose RNA-seq, normalized by the DESeq2 R package, related to Fig. 2 and Extended Data Fig. 3.

Supplementary Table 2 (download XLSX )

List of 81 genes encoding secretory proteins, related to Fig. 2.

Supplementary Table 3 (download XLSX )

List of changed genes in intestinal crypt RNA-seq and list of gene counts from intestinal crypt RNA-seq, normalized by the DESeq2 R package, related to Figs. 5 and 7 and Extended Data Figs. 6 and 7.

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Primers for RT–qPCR, constructs, related to Figs.2, 4, 7 and 8 and Extended Data Figs. 2–8 and 10.

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List of hAFABP-interacted proteins, identified by MS from UAS-hAFABP-3xHA fly adipose tissue, related to Extended Data Fig. 7.

Supplementary Table 6 (download XLSX )

Full Drosophila genotypes as they appear in each figure, related to Figs. 1–3 and 6, and Extended Data Figs. 2–5, 7, 9 and 10.

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List of medium composition for mouse organoid culture and clinical characteristics of participants.

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GWAS accession code, related to Extended Data Fig.1

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Liu, Z., Chen, Y., Yan, J. et al. Obesity impairs gut repair via AFABP-mediated iron overload in intestinal stem cells. Nat Metab 8, 74–95 (2026). https://doi.org/10.1038/s42255-025-01425-4

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