Impact of oral supplementation with l-glutamine on gut microbiota of obese and overweight human adults

Orientador: Patricia de Oliveira PradaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências AplicadasResumo: Introdução: Inúmeros fatores contribuem para o aumento da obesidade em todo o mundo. Recentemente, a microbiota intestinal ganhou destaque devido ao seu poder de predispor ou inibir o ganho de peso. Alguns nutrientes são capazes de alterar a composição da microbiota intestinal, o que pode trazer efeitos benéficos ou maléficos, como a obesidade. O aminoácido L-glutamina, além de suas inúmeras funções orgânicas e imunológicas, é conhecido por desempenhar importante papel no trofismo intestinal. O objetivo do presente estudo foi investigar alterações na composição da microbiota intestinal de indivíduos com sobrepeso ou obesidade após suplementação oral com L-glutamina. Métodos: Voluntários com sobrepeso ou obesidade foram selecionados para ingerir 30g de L-glutamina (GLN) por via oral ao dia, por um período de quatorze dias. O grupo controle recebeu L-alanina (ALA) no mesmo tempo e proporção. Amostras de sangue e fezes foram coletadas para análises. Para classificação taxonômica das bactérias intestinais, foi realizado sequenciamento do gene 16S RNA ribossomal. Análises de bioinformática foram conduzidas com base no banco de dados RDP (Ribosomal Database Project). Para análise dos dados, estratégias estatísticas variadas foram utilizadas. Resultados: Após quatorze dias de suplementação, os participantes do grupo GLN exibiram diferenças significativas nos filos Actinobacteria e Firmicutes e nos gêneros Dialister, Dorea, Pseudobutyrivibrio e Veillonella, comparados com o grupo ALA. A razão F / B (Firmicutes / Bacteroidetes), um bom biomarcador para a obesidade, reduziu de 0,85 para 0,57 no grupo GLN e ao contrário, aumentou de 0,91 para 1,12 no grupo ALA. Conclusão: A suplementação oral do aminoácido L-glutamina, em humanos com sobrepeso e obesidade, por um período de quatorze dias, promove alterações na composição da microbiota intestinal similares às promovidas pela perda de pesoAbstract: Introduction: Several factors contribute to the increase of obesity worldwide. Recently, the gut microbiota gained prominence due to its power to predispose or inhibit weight gain. Some nutrients are able to change the composition of the gut microbiota, what can bring beneficial or harmful effects, such as obesity. The amino acid L-glutamine, in addition to its numerous organic and immune functions, is known to play an important role in intestinal tropism. The aim of this study was to investigate changes in the composition of the gut microbiota of overweight or obese adults after oral supplementation with L-glutamine. Methods: Overweight or obese subjects were selected to orally ingest 30g of L-glutamine (GLN) daily for a period of fourteen days. The control group received L-alanine (ALA) in the same period and proportion. Blood and feces were collected for analysis. The 16S rRNA gene sequence was performed for taxonomic classification of intestinal bacteria. Bioinformatics analysis was conducted based on RDP (Ribosomal Database Project). For data analysis, varied statistical strategies were used. Results: After fourteen days of supplementation, participants in the GLN group showed significant differences in the Firmicutes and Actinobacteria phyla and Dialister, Dorea, Pseudobutyrivibrio and Veillonella genera, compared with the ALA group. The F / B (Firmicutes / Bacteroidetes) ratio, a good biomarker for obesity, decreased from 0.85 to 0.57 in GLN group and, as opposed, increased from 0.91 to 1.12 in the ALA group. Conclusion: Oral supplementation with the amino acid L-glutamine in overweight and obese humans, for a period of fourteen days, alters the composition of the gut microbiota in a similar way to weight lossMestradoNutriçãoMestra em Ciências da Nutrição e do Esporte e Metabolism

Oral Supplementation With L-glutamine Alters Gut Microbiota Of Obese And Overweight Adults: A Pilot Study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Objective: The aim of this study was to determine whether oral supplementation with L-glutamine (GLN) modifies the gut microbiota composition in overweight and obese adults. Methods: Thirty-three overweight and obese adults, ages between 23 and 59 y and body mass index between 25.03 and 47.12 kg/m(2), were randomly assigned to receive either oral supplementation with 30 g of L-alanine (ALA group control) or 30 g of GLN (GLN group) daily for 14 d. We analyzed the gut microbiota composition with new-generation sequencing techniques and bioinformatics analysis. Results: After 14 d of supplementation, adults in the GLN group exhibited statistically significant differences in the Firmicutes and Actinobacteria phyla compared with those in the ALA group. The ratio of Firmicutes to Bacteroidetes, a good biomarker for obesity, decreased in the GLN group from 0.85 to 0.57, whereas it increased from 0.91 to 1.12 in the ALA group. At the genus level, Dialister, Dorea, Pseudobutyrivibrio, and Veillonella, belonging to the Firmicutes phylum, had statistically significant reduction. Conclusion: Oral supplementation with GLN, for a short time, altered the composition of the gut microbiota in overweight and obese humans reducing the Firmicutes to Bacteroidetes ratio, which resembled weight loss programs already seen in the literature. (C) 2015 Elsevier Inc. All rights reserved.316884889Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientiflco e Tecnologico, Institut Nacional Ciencia e Tecnologia em Obesidade e Diabetes [573856/2008-7]UNIVERSAL [481084/2013-4]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Oral Glutamine Supplementation Reduces Obesity, Pro-Inflammatory Markers, and Improves Insulin Sensitivity in DIO Wistar Rats and Reduces Waist Circumference in Overweight and Obese Humans

In the present study, we aimed to investigate whether chronic oral glutamine (Gln) supplementation may alter metabolic parameters and the inflammatory profile in overweight and obese humans as well as whether Gln may modulate molecular pathways in key tissues linked to the insulin action in rats. Thirty-nine overweight/obese volunteers received 30 g of Gln or alanine (Ala-control) for 14 days. Body weight (BW), waist circumference (WC), hormones, and pro-inflammatory markers were evaluated. To investigate molecular mechanisms, Gln or Ala was given to Wistar rats on a high-fat diet (HFD), and metabolic parameters, euglycemic hyperinsulinemic clamp with tracers, and Western blot were done. Gln reduced WC and serum lipopolysaccharide (LPS) in overweight volunteers. In the obese group, Gln diminished WC and serum insulin. There was a positive correlation between the reduction on WC and LPS. In rats on HFD, Gln reduced adiposity, improved insulin action and signaling, and reversed both defects in glucose metabolism in the liver and muscle. Gln supplementation increased muscle glucose uptake and reversed the increased hepatic glucose production, in parallel with a reduced glucose uptake in adipose tissue. This insulin resistance in AT was accompanied by enhanced IRS1 O-linked-glycosamine association in this tissue, but not in the liver and muscle. These data suggest that Gln supplementation leads to insulin resistance specifically in adipose tissue via the hexosamine pathway and reduces adipose mass, which is associated with improvement in the systemic insulin action. Thus, further investigation with Gln supplementation should be performed for longer periods in humans before prescribing as a beneficial therapeutic approach for individuals who are overweight and obese