Serum Levels of Lipopolysaccharides and Risk of Advanced Colorectal Adenoma

Abstract

Background and objectives: Production of lipopolysaccharides (LPS) from the outer membrane of Gram-negative bacteria promotes the survival of cancer cells. Systemic level of LPS is considered a biomarker for microbial translocation. The association between LPS and the risk of colorectal tumors is not well known. The goal of this study was to examine the association between LPS serum levels and risk of advanced colorectal adenoma (ACA). Methods: In this colonoscopy clinic-based case-control study, cases were male patients with a diagnosis of ACA, and controls were polyp-free male participants. Cases and controls were individually matched by age, ethnicity, and blood collection time. Information on demographics, lifestyle, and medical history was obtained using structured questionnaires. Serum levels of LPS were quantitated using the kinetic limulus amebocyte lysate assay. Multivariable conditional logistic regression model was used to estimate the odds ratio and its 95% confidence interval of the ACA in association with serum LPS adjusting for cigarette smoking, body mass index, and medical history. Results: We examined 43 cases and 43 paired controls, with a mean age of 62 years. There was no significant difference in serum LPS levels between the cases and controls (0.28 vs. 0.25 endotoxin units (EU)/mL, P = 0.58 for the non-parametric test). The adjusted odds ratio and its 95% confidence interval of ACA was 1.83 (0.40-8.24) in multivariable logistic regression model. Conclusions: Serum levels of LPS were not statistically significantly associated with an increased risk of ACA in this preliminary study.

Protective Effect of Limosilactobacillus fermentum ME-3 against the Increase in Paracellular Permeability Induced by Chemotherapy or Inflammatory Conditions in Caco-2 Cell Models

“…Of great importance, besides Irinotecan, we demonstrated that this probiotic could also protect against the membrane damage provoked by LPS-induced inflammation, LPS excess being a prevalent trait of dysbiosis, chronic gut inflammation, and colon cancer [ 40 , 41 , 42 ]. To address this point, a Caco-2/dU937 co-culture model of intestinal inflammation was treated with LPS, thus provoking FITC-dextran flux across the Caco-2 monolayer.…”

LPS—Is It a Major Liability Factor for Cancer Risk and Severity?

“…In a recent study, Chen et al 7 investigated the association between LPS serum levels and risk of ACA.In that colonoscopy clinic-based study, male patients with diagnosis of ACA and polyp-free control individuals were phenotyped for comparative analyses with age, ethnicity, and information on demographics, lifestyle, and medical history along with serum levels of LPS measurement.Examining the LPS levels based on the characteristics and substratification of adenoma, the investigators showed that patients with largesized adenoma (>2 cm), villous adenoma, or high-grade dysplasia tended to have higher serum levels of LPS compared to patients with smaller, tubular adenoma, and adenoma without high-grade dysplasia, respectively. Although LPS levels were slightly higher in patients with ACA compared to controls, the subtle differences in the LPS levels did not reach statistical significance.…”