2026-04-22T17:33:27Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/99872025-06-12T11:23:01Zcom_10259_9895com_10259_3989com_10259.4_106com_10259_2604col_10259_9896

Dietary tryptophan depletion alters the faecal bacterial community structure of compulsive drinker rats in schedule-induced polydipsia Merchán Carrillo, Ana Pérez Fernández, Cristian Antonio López, María J. Moreno Casco, José Joaquín Moreno-Montoya, Margarita Sánchez Santed, Fernando Flores, Pilar Compulsivity Schedule-induced polydipsia Gut microbiota Chronic tryptophan depletion PCR-DGGE Brain-derived neurotrophic factor Triptófano Bacterias-Metabolismo Psicología Tryptophan Microbial metabolism Psychology Rationale: Compulsive behaviour, present in different psychiatric disorders such as obsessive-compulsive disorder, schizophrenia and drug abuse, is associated with altered levels of serotonin (5-hydroxytryptamine, 5-HT). The gut microbiota regulates tryptophan (TRP) metabolism and may affect global 5-H synthesis in the enteric and central nervous systems, suggesting a possible involvement of gut microbiota in compulsive spectrum disorders. Objectives: The present study investigated whether chronic TRP depletion by diet alters the faecal bacterial community profiles of compulsive versus non-compulsive rats in schedule-induced polydipsia (SIP). Peripheral plasma 5-HT and brain-derived neurotrophic factor (BDNF) levels were evaluated. Methods: Wistar rats were selected as High Drinkers (HD) or Low Drinkers (LD) according to their SIP behaviour and were fed for 14 days with either a TRP-free diet (T-) or a TRP-supplemented diet (T+). The faecal bacterial community structure was investigated with 16S rRNA gene-targeted denaturing gradient gel electrophoresis (DGGE) fingerprinting analysis. Results: Compulsive HD rats showed a lower bacterial diversity than LD rats, irrespectively of the diet. The TRP-depleted HD rats, the only group increasing compulsive licking in SIP, showed a reduction of bacterial evenness and a highly functionally organized community compared with the other groups, indicating that this bacterial community is more fragile to external changes due to the dominance of a low number of species. The chronic TRP depletion by diet effectively reduced peripheral plasma 5-HT levels in both HD and LD rats, while plasma BDNF levels were not altered. Conclusions: These results highlight the possible implication of reduced microbial diversity in compulsive behaviour and the involvement of the serotonergic system in modulating the gut brain-axis in compulsive spectrum disorders. This study was funded by grants from the Ministerio de Ciencia, Innovación y Universidades (Spanish Government) and Fondo Europeo de Desarrollo Regional, PSI2017–86,847-C2–1-R and PGC2018–099,117-B-C21, and by University of Almería (PPUENTE2020/003), with the help of the Post-doctoral fellowship “Contrato Puente” at University of Almería. 2025-01-22T09:07:54Z 2025-01-22T09:07:54Z 2021-05 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion 0031-9384 http://hdl.handle.net/10259/9987 10.1016/j.physbeh.2021.113356 eng Physiology & Behavior. 2021, V. 233, 113356 https://doi.org/10.1016/j.physbeh.2021.113356 info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/PSI2017-86847-C2-1-R/ES/CORRELATOS NEURO-BIOLOGICOS DE LOS DESORDENES DEL NEURODESARROLLO INDUCIDOS POR FACTORES GENETICOS O AMBIENTALES/ info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-099117-B-C21/ES/HACIA UNA NUEVA CARACTERIZACION Y TRATAMIENTO DE LOS TRASTORNOS DEL ESPECTRO IMPULSIVO-COMPULSIVO: UN ENFOQUE TRASLACIONAL/ info:eu-repo/grantAgreement/UAL//PPUENTE2020%2F003/ Attribution-NonCommercial-NoDerivatives 4.0 Internacional http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess application/pdf Elsevier