Gut microbiota (GM) after bariatric surgery (BS) has been considered as a factor associated with metabolic improvements and weight loss. In this systematic review, we evaluate changes in the GM, characterized by 16S rRNA and metagenomics techniques, in obese adults who received BS. The PubMed, Scopus, Web of Science, and LILACS databases were searched. Two independent reviewers analyzed articles published in the last ten years, using Rayyan QCRI. The initial search resulted in 1275 documents, and 18 clinical trials were included after the exclusion criteria were applied. The predominance of intestinal bacteria phyla varied among studies; however, most of them reported a greater amount of Bacteroidetes (B), Proteobacteria (P), and diversity (D) after BS. Firmicutes (F), B, and the (F/B) ratio was inconsistent, increasing or decreasing after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) were conducted, compared to before surgery. There was a reduction in the relative proportion of F. Moreover, a higher proportion of Actinobacteria (A) was observed after RYGB was conducted. However, the same was not identified when SG procedures were applied. Genera abundance and bacteria predominance varied according to the surgical procedure, with limited data regarding the impact on phyla. The present study was approved by PROSPERO, under registration number CRD42020209509.

Background: The fat mass and obesity-related (FTO) gene has a strong relationship with obesity, extreme obesity and inflammatory state, and may also be associated with food intake regulation. Objective: The aim of the present study was to evaluate the influence of the rs9939609 single-nucleotide polymorphism of the FTO gene on appetite, ghrelin, leptin, interleukin 6 (IL6), tumor necrosis factor α (TNFα) levels and food intake of morbidly obese women. Materials and methods: The study comprised 70 women, aged between 20 and 48 years, from Rio de Janeiro, Brazil. The participants were selected according to the body mass index between 40 and 60 kg/m². Anthropometric and biochemical data were measured during fasting. Hormones and inflammatory data were measured before and after the participants ate an isocaloric meal. Dietary records were calculated and analyzed using a nutritional assessment program. Visual analog scales were used for behaviors of the sensations of appetite and food preferences. The FTO rs9939609 variant was genotyped using real-time polymerase chain reaction. Results: Participants with the AA genotype had lower values of ghrelin and IL6 and higher values of leptin than those with TT and TA in the postprandial period. Comparing the plasma concentrations of ghrelin, insulin, IL6 and TNFα intragenotypes, it was observed that those with TT had decreased leptin and increased IL6 at the postprandial period. Subjects with TA showed increased postprandial IL6, and those with AA had decreased postprandial ghrelin. There was no difference in TNFα intra- and intergenotypes. The postprandial sensations of hunger were lower in AA than those with TT. There were differences between genotypes regarding ingested grams of protein by weight, cholesterol, B3, B5, B6 and B12 vitamins, and selenium potassium and sodium minerals. Conclusion: These findings suggest that genetics may exert an influence on physiologic factors and might alter eating behavior.

BACKGROUND: Along with the augmentation in obesity rates in recent years, the demand for bariatric surgery has startlingly increased. Nutritional counseling in the preoperative period is very important because it contributes to higher success rate in the post-operative period. AIM: To assess the nutritional status of patients in a multidisciplinary program for the treatment of severe obesity and pre-operatively for bariatric surgery, characterizing the consumption of healthy nutrients. METHODS: A retrospective analysis of 30 patients was conducted. Personal information, anthropometric data and dietary assessment by 24-hour food record were collected. The analysis of energy intake was performed in Dietpro 5.1 Professional(r) program. The statistical treatment of the caloric intake was performed by an ANOVA test with Bonferroni´s post hoc and for anthropometric data the paired t test was used. RESULTS: From the total, 73% of the patients were women and 27% male, mean age was 48.4+12.9 and 49.8+8.1, respectively. A lower weight in the 5th appointment was observed when compared with the 1st one. There was a reduction in caloric intake in the 2nd, 3rd, 4th and 5th appointments when compared with the 1st. It was observed that in the 5th appointment more than 50% of the patients underwent six meals a day. There was an increase in the consumption of fruit along the appointments and 72.2% of patients consumed 1-2 servings of fruit a day. Vegetables intake was high in all appointments in the pre-operative period and, although low, the whole grain products consumption has increased during the pre-operative period achieving 30% of the study population. CONCLUSION: There was a decrease in body weight, a trend in the decrease of the body mass index and waist circumference and quantitative and qualitative improvement of food consumption.

A obesidade é uma doença crônica e tem se tornado uma epidemia em todo o mundo. Sua etiologia é multifatorial e o tratamento complexo, envolvendo dieta, exercícios físicos, fármacos e, em casos mais graves, cirurgia. De acordo com os guias e consensos, nacionais e internacionais, a distribuição dos macronutrientes fica em torno de 35% a 65% do valor energético total (VET) de carboidratos, 15 a 25% do VET de proteínas e 20 a 40% do VET de lipídios. Por meio de uma revisão de literatura, foram encontradas recomendações controversas. Conforme análise crítica dos pesquisadores envolvidos e de acordo com resultados de pesquisas recentes, concluiu-se que dieta hipocalórica (restrição de 500 a 750 kcal/dia), hiperproteica (>25% do VET), hipoglicídica e normolipídica foi eficaz na perda e manutenção do peso a longo prazo. Em relação aos lipídios, verificou-se que a dieta deve ser mais qualitativa, com a redução na ingestão de colesterol, gorduras saturadas e trans. O consumo de fibras deve ser estimulado. Dietas restritivas não se mostraram sustentáveis por um longo período, mas podem ser usadas em um período determinado. Além disso, a alta prevalência de deficiência de micronutrientes em indivíduos com obesidade foi consensual entre os autores, inclusive antes da cirurgia bariátrica. Concluiu-se que a adesão dietética e, consequentemente, o balanço negativo são fatores decisivos para a promoção da perda de peso. O planejamento alimentar deve ser flexível e individualizado e o contato entre o nutricionista e o paciente deve ser constante, visando a reeducação alimentar. O presente artigo realizou uma análise crítica das recomendações de macro e micronutrientes na obesidade visando contribuir para o tratamento dietético dessa população.