Protective Role of Spermidine in Colitis and Colon Carcinogenesis

Gastroenterology. 2022 Mar;162(3):813-827.e8. doi: 10.1053/j.gastro.2021.11.005. Epub 2021 Nov 10.


Background & aims: Because inflammatory bowel disease is increasing worldwide and can lead to colitis-associated carcinoma (CAC), new interventions are needed. We have shown that spermine oxidase (SMOX), which generates spermidine (Spd), regulates colitis. Here we determined whether Spd treatment reduces colitis and carcinogenesis.

Methods: SMOX was quantified in human colitis and associated dysplasia using quantitative reverse-transcription polymerase chain reaction and immunohistochemistry. We used wild-type (WT) and Smox-/- C57BL/6 mice treated with dextran sulfate sodium (DSS) or azoxymethane (AOM)-DSS as models of colitis and CAC, respectively. Mice with epithelial-specific deletion of Apc were used as a model of sporadic colon cancer. Animals were supplemented or not with Spd in the drinking water. Colonic polyamines, inflammation, tumorigenesis, transcriptomes, and microbiomes were assessed.

Results: SMOX messenger RNA levels were decreased in human ulcerative colitis tissues and inversely correlated with disease activity, and SMOX protein was reduced in colitis-associated dysplasia. DSS colitis and AOM-DSS-induced dysplasia and tumorigenesis were worsened in Smox-/- vs WT mice and improved in both genotypes with Spd. Tumor development caused by Apc deletion was also reduced by Spd. Smox deletion and AOM-DSS treatment were both strongly associated with increased expression of α-defensins, which was reduced by Spd. A shift in the microbiome, with reduced abundance of Prevotella and increased Proteobacteria and Deferribacteres, occurred in Smox-/- mice and was reversed with Spd.

Conclusions: Loss of SMOX is associated with exacerbated colitis and CAC, increased α-defensin expression, and dysbiosis of the microbiome. Spd supplementation reverses these phenotypes, indicating that it has potential as an adjunctive treatment for colitis and chemopreventive for colon carcinogenesis.

Trial registration: NCT01091558.

Keywords: Chemoprevention; Colitis-Associated Carcinogenesis; Inflammatory Bowel Disease; Intestinal Microbiota; Polyamines; Spermidine; α-Defensins.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenomatous Polyposis Coli Protein / genetics
  • Animals
  • Azoxymethane
  • Carcinogenesis / drug effects*
  • Carcinogenesis / genetics*
  • Colitis / chemically induced
  • Colitis / enzymology
  • Colitis / genetics*
  • Colitis / prevention & control
  • Colitis, Ulcerative / enzymology
  • Colitis, Ulcerative / genetics
  • Colon / enzymology
  • Colon / pathology
  • Colonic Neoplasms / genetics*
  • Colonic Neoplasms / prevention & control
  • Dextran Sulfate
  • Gastrointestinal Microbiome / drug effects
  • Gene Expression Regulation / drug effects
  • Humans
  • Intestinal Mucosa / enzymology
  • Intestinal Mucosa / pathology
  • Male
  • Mice
  • Oxidoreductases Acting on CH-NH Group Donors / genetics*
  • Oxidoreductases Acting on CH-NH Group Donors / metabolism
  • Precancerous Conditions / enzymology
  • Protective Factors
  • RNA, Messenger / metabolism
  • Severity of Illness Index
  • Spermidine / metabolism
  • Spermidine / pharmacology
  • Spermidine / therapeutic use*
  • Weight Loss / drug effects
  • alpha-Defensins / genetics
  • alpha-Defensins / metabolism


  • Adenomatous Polyposis Coli Protein
  • DEFA5 protein, human
  • DEFA6 protein, human
  • RNA, Messenger
  • adenomatous polyposis coli protein, mouse
  • alpha-Defensins
  • Dextran Sulfate
  • Oxidoreductases Acting on CH-NH Group Donors
  • polyamine oxidase
  • Azoxymethane
  • Spermidine

Associated data