ABSTRACT
Bile acids (BA) are among the most abundant metabolites produced by the gut microbiome. Primary BAs produced in the liver are converted by gut bacterial 7-α-dehydroxylation into secondary BAs, which can differentially regulate host health via signaling based on their varying affinity for BA receptors. Despite the importance of secondary BAs in host health, the regulation of 7-α-dehydroxylation and the role of diet in modulating this process is incompletely defined. Understanding this process could lead to dietary guidelines that beneficially shift BA metabolism. Dietary fiber regulates gut microbial composition and metabolite production. We tested the hypothesis that feeding mice a diet rich in a fermentable dietary fiber, resistant starch (RS), would alter gut bacterial BA metabolism. Male and female wild-type mice were fed a diet supplemented with RS or an isocaloric control diet (IC). Metabolic parameters were similar between groups. RS supplementation increased gut luminal deoxycholic acid (DCA) abundance. However, gut luminal cholic acid (CA) abundance, the substrate for 7-α-dehydroxylation in DCA production, was unaltered by RS. Further, RS supplementation did not change the mRNA expression of hepatic BA producing enzymes or ileal BA transporters. Metagenomic assessment of gut bacterial composition revealed no change in the relative abundance of bacteria known to perform 7-α-dehydroxylation. P. ginsenosidimutans and P. multiformis were positively correlated with gut luminal DCA abundance and increased in response to RS supplementation. These data demonstrate that RS supplementation enriches gut luminal DCA abundance without increasing the relative abundance of bacteria known to perform 7-α-dehydroxylation.
Subject(s)
Gastrointestinal Microbiome , Resistant Starch , Mice , Male , Female , Animals , Gastrointestinal Microbiome/physiology , Bile Acids and Salts , Dietary Supplements , Bacteria/genetics , Deoxycholic AcidSubject(s)
Abdomen, Acute/complications , Mucocutaneous Lymph Node Syndrome/complications , Abdomen, Acute/diagnosis , Abdomen, Acute/physiopathology , Acute Disease , Appendicitis/etiology , Appendicitis/surgery , Gastrointestinal Tract , Humans , Hyperplasia , Male , Mucocutaneous Lymph Node Syndrome/diagnosis , Mucocutaneous Lymph Node Syndrome/physiopathology , Vasculitis/etiologyABSTRACT
Se presenta un caso pediátrico de piedra blanca autóctono del estado de Guerrero, México; producido por Trichosporon beigelli, localizado en folículos pilosos de la cabeza en una paciente pediátrica, que inicialmente fue erróneamente diagnosticado como pediculosis de la cabeza. El diagnóstico etiológico fue realizado mediante examen directo de pelos aclarados con hidróxido de potasio, cultivo en Sabouraud, frotis con tinción de Gram de cultivo e identificación de la especie del hongo mediante pruebas bioquímicas para levaduras en el equipo MicroScan.