(P11-016-23) Colonic Content From Offspring Born to Dams of High-Fat, High-Sucrose Diet Modulates IL-8 Secretion in Lipopolysaccharide-Stimulated HT-29 Cells

Objectives: Vitamin D receptor (VDR) regulates the production of cathelicidin (CAMP), an antimicrobial peptide, which could further affect gut microbiome. Previously, we showed that maternal high-fat, high-sucrose (HFS) diet contributed to low vitamin D status and inflammation in offspring. Here, we assessed if maternal HFS can alter colonic content in offspring to promote colonic inflammation using an in vitro model.

Methods: Fecal contents collected from pup (15-weeks old) born to standard chow-fed dams (CON) or HFS-fed dams, were subjected to homogenization to yield fecal extract stocks. Two colorectal cancer cell lines, HT29 and SW620, were utilized and pre-treated with fecal extracts at varying concentrations (2X, 5X, and 10X, respectively) for 2 hours prior to stimulation with E. coli lipopolysaccharides (LPS) to induce inflammation. Supernatant was collected and evaluated for IL-8 production. To determine if short chain fatty acids (SCFA) mediate the inflammatory response via vitamin D signaling, HT29 cells were further treated with butyrate, propionate, and acetate, respectively, and mRNA expressions of VDR and CAMP were assessed.

Results: Fecal extracts from CON or HFS offspring suppressed IL-8 secretion at a dose-dependent manner in HT29 cells. IL-8 concentrations were lowest when cells were treated with 2X fecal extracts from offspring of CON or HFS dams. However, compared to offspring of CON dams of the same dose, 5X fecal extract obtained from HFS offspring lowered IL-8 secretion by 60%. Further, treatment with butyrate and propionate, respectively, but not acetate, attenuated VDR mRNA expressions by 30%, while CAMP mRNA expressions was significantly enhanced, compared to LPS treatment alone. Data was not obtained from SW620 cell line due to its low sensitivity to LPS.

Conclusions: We show that maternal HFS may induce a shift of colonic content to alter inflammatory response in offspring, a pathway that could be mediated by SCFA via activation of VDR-CAMP axis. Though mechanisms remained to be elucidated and further studies are needed to confirm our preliminary observations, our data may suggest that prenatal dietary modifications could be a useful for colonic inflammation prevention.

Funding Sources: Texas State University startup funds granted to Dr. Gar Yee Koh.