P071. Gelenterum ameliorates murine colitis while modulating gut microbiota and intestinal mucus layer
F. Scaldaferri1, L.R. Lopetuso1, V. Petito1, V. Gerardi1, M. Bilotta2, A. Poscia3, M. Papi4, G. Maolucci5, V. Cufino6, E. Stigliano6, V. Arena6, G. Delogu2, M. Sanguinetti2, M. De Spirito4, A. Sgambato6, A. Gasbarrini1, 1Catholic University of Sacred Hearth, Internal Medicine, Gastroenterology Division, Rome, Italy, 2Catholic University of Sacred Hearth, Istitute of Microbiology, Rome, Italy, 3Catholic University of Sacred Hearth, Insitute of Hygiene, Rome, Italy, 4Catholic University of Sacred Hearth, Istitute of Phisics, Rome, Italy, 5Catholic University of Sacred Hearth, Institute of Phisics, Rome, Italy, 6Catholic University of Sacred Hearth, Institute of Pathology, Rome, Italy
Gelenterum, a gelatin powder containing Tannic Acids, is used for diarrhea in children. Few information exist on its mechanisms of action, involving gel formation and bacterial toxin sequestration. Aim of this study was to evaluate the effect and mechanisms of action of Gelenterum in the murine model of acute colitis by DSS.
C57BL/6 mice receiving 2.5% DSS in drinking water ad libitum for 8 days, at day 4, 5, 6 and 7, were treated with gelenterum 1 mg or 10 mg in 200 µl of tap water, or saline solution, given orally by gavage starting day 3. Body weight, occult blood test and stool consistency were measured every other day to calculate Disease Activity Index (DAI), as assessment of severity of colitis. Mice were sacrificed at day 9, serum samples were collected, colon length measured for histology assessment by Rachmilewitz score. To characterize gut microbiota modulation, stools were collected at day 0, 5 and 9 and cultured in selective media. RT-PCR was also performed on fecal as well as on intestinal samples. Colonic mucus layer were analysed at confocal microscopy at 2 photon and atomic force microscope. Finally, LPS and peptidoglycan were evaluated by ELISA test in peripheral blood.
Gelenterum reduced DAI and body weight loss in treated mice, being 10 mg more efficacious than 1 mg dose. Gelenterum treated mice displayed a longer colon. In fecal culture, Acinetobacteria, Enterobacteria, Enterococci and Lactobacilli grew from stool as well as from intestinal culture. Treated mice showed a lower concentration of Enterobacteria and Enterococci, and higher concentration of lactobacilli. At confocal microscopy, intestinal samples from healthy and treated mice displayed a similar structure in mucus layer thickness and composition, while samples from placebo group had no mucus layer or thinner stratus. Atomic force microscopy confirmed these findings, suggesting that mucus in treated mice could derive from 2 different sources. Serum LPS levels were lower in non colitic mice as well as in Gelenterum treated mice, while no significant variation in Peptidoglycan serum levels was observed.
Gelenterum decreased the severity of colitis in mice while preserving colonic mucus appearance, modifying gut microbiota composition and supporting gut homeostasis. Further analysis are required to better define mechanisms of action underlying these findings.