ABSTRACT
ABSTRACT Introduction: Studies suggest that weight loss induced by bariatric surgery and the remission of some comorbidities may be related to changes in the microbiota profile of individuals undergoing this procedure. In addition, there is evidence that manipulation of the intestinal microbiota may prove to be a therapeutic approach against obesity and metabolic diseases. Objective: To verify the changes that occur in the intestinal microbiota of patients undergoing bariatric surgery, and the impact of the usage of probiotics in this population. Methods: Articles published between 2007 and 2017 were searched in Medline, Lilacs and Pubmed with the headings: bariatric surgery, microbiota, microbiome and probiotics, in Portuguese, English and Spanish. Of the 166 articles found, only those studies in adults subjected to either Roux-en-Y gastric bypass or sleeve vertical gastrectomy published in original articles were enrolled. In the end, five studies on the change of intestinal microbiota composition, four on the indirect effects of those changes and three on the probiotics administration on this population were enrolled and characterized. Conclusion: Bariatric surgery provides changes in intestinal microbiota, with a relative increase of the Bacteroidetes and Proteobacteria phyla and reduction of Firmicutes. This is possibly due to changes in the gastro-intestinal flux, coupled with a reduction in acidity, in addition to changes in eating habits. The usage of probiotics seems to reduce the gastro-intestinal symptoms in the post-surgery, favor the increase of vitamin B12 synthesis, as well as potentiate weight loss.
RESUMO Introdução: Estudos sugerem que a perda de peso induzida pela cirurgia bariátrica e a remissão de algumas comorbidades podem estar relacionadas às mudanças no perfil da microbiota dos indivíduos submetidos a este procedimento. Além disso, há indícios de que a manipulação da microbiota intestinal pode vir a ser abordagem terapêutica contra a obesidade e doenças metabólicas. Objetivo: Verificar as mudanças que ocorrem na microbiota intestinal de pacientes submetidos à cirurgia bariátrica, e o impacto do uso dos probióticos nessa população. Métodos: Foi realizada a busca de artigos publicados entre os anos de 2007 e 2017 nas bases de dados Medline, Lilacs e PubMed com os descritores: cirurgia bariátrica, microbiota, microbioma e probióticos em português, inglês e espanhol. Dos 166 artigos encontrados, foram selecionados apenas os estudos realizados em adultos, submetidos ao bypass gástrico em Y-de-Roux ou gastrectomia vertical sleeve publicados em artigos originais. Ao final, foram selecionados e categorizados cinco estudos sobre a mudança na composição da microbiota intestinal, quatro sobre os efeitos indiretos dessas mudanças e três sobre a administração de probióticos nessa população. Conclusão: A cirurgia bariátrica proporciona mudanças na microbiota intestinal com aumento relativo dos filos Bacteroidetes e Proteobactéria e redução de Firmicutes. Isso se deve, possivelmente, às alterações no trânsito gastrointestinal com redução da acidez intestinal além de modificação dos hábitos alimentares. O uso de probióticos parece reduzir os sintomas gastrointestinais no pós-operatório, favorecer o aumento de síntese de vitamina B12 e potencializar a perda de peso.
Subject(s)
Humans , Adult , Gastric Bypass/methods , Probiotics/therapeutic use , Gastrointestinal Microbiome/physiology , Gastrectomy/methods , Postoperative Period , Weight Loss/physiology , Treatment Outcome , Bacteroidetes/growth & developmentABSTRACT
Se estudió el efecto de la radiación ultravioleta (RUV) sobre dos cepas bacterianas marinas antárticas (UVps y UVvi) en la columna de agua de la caleta Potter (Shetland del Sur, Antártida). Frascos de cuarzo con las cepas en estudio fueron expuestos a la radiación solar en superficie, a 1 m y a 3 m de profundidad. Se realizaron ensayos con exposición directa y con filtros interferenciales que discriminaron la radiación UVA y la UVB. En otros ensayos se simuló una mezcla vertical de 4 m/h. Ambas cepas mostraron una disminución significativa del número de unidades formadoras de colonias, tanto en superficie como a 1 m de profundidad, luego de exponerlas a dosis superficiales de UVB de 8,4 kJ m-2. El estudio con filtros interferenciales mostró una disminución significativa de la viabilidad en ambos tratamientos UV en superficie y a 1 m. La cepa UVps mostró mayor sensibilidad a la UVB que a la UVA. La mezcla vertical amortiguó el daño causado por la UVB cuando la dosis en superficie fue de 4,8 kJ m-2. Este efecto amortiguador no se observó cuando la dosis en superficie fue de 7,7 kJ m-2. Estos resultados muestran que el efecto negativo de la RUV sobre el bacterioplancton sería particularmente importante en el primer metro de profundidad de las aguas costeras antárticas con abundante material particulado en suspensión.
The effect of UV radiation on two Antarctic marine bacterial strains (UVps and UVvi) was studied in the water column of Potter Cove (South Shetland, Antarctica). Quartz flasks were filled with the bacterial suspensions and exposed to solar radiation at 0 m, 1 m and 3 m depth. Assays using flasks exposed to direct solar radiation and others using flasks covered with/by interferential filters which discriminate between UVA and UVB, were performed. In other assays, a vertical mixing of 4 m/h was simulated. Both strains showed a significant decrease in viability (expressed as colony - forming units) when exposed to a surface UVB dose of 8.4 kJ m-2. Studies with interferential filters showed a significant decrease at 0 and 1 m depth under both UV treatments. The UVps strain appeared to be more sensitive to UVB than to UVA. Damage produced by UVB was attenuated by the vertical mixing when the surface UVB dose was 4.8 kJ m-2. This effect was not observed when surface UVB dose was 7.7 kJ m-2. These results show that the negative effect caused by UVB radiation on the bacterioplankton would be significant only in the first meter of water column of the Antarctic coastal waters with high levels of suspended particulate material.