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Background: Bariatric surgery induces significant weight loss, increases insulin sensitivity, and improves dyslipidemia. As one of the most widely performed bariatric surgeries, laparoscopic sleeve gastrectomy (LSG) is thought to improve the metabolic profile along with weight loss. The objective of this study was to evaluate longitudinal changes in the serum metabolite levels after LSG and elucidate the underlying mechanisms of metabolic improvement. Methods: Clinical metabolic parameters and serum samples were collected preoperatively and at 1, 3, and 6 months postoperatively from nine patients with obesity undergoing LSG. Serum metabolites were measured using a non-targeted metabolic liquid chromatography–mass spectrometry method. Results: During the 1, 3, and 6 months postoperative follow-up, the body mass index, HOMA-IR, and liver fat content showed a gradual descending trend. A total of 328 serum metabolites were detected, and 38 were differentially expressed. The up-regulated metabolites were mainly enriched in ketone body metabolism, alpha-linolenic acid and linoleic acid metabolism, pantothenate and CoA biosynthesis, glycerolipid metabolism, and fructose and mannose degradation, while the down-regulated metabolites were closely related to caffeine metabolism, oxidation of branched-chain fatty acids, glutamate metabolism, and homocysteine degradation. Notably, nine metabolites (oxoglutarate, 2-ketobutyric acid, succinic acid semialdehyde, phthalic acid, pantetheine, eicosapentaenoate, 3-hydroxybutanoate, oxamic acid, and dihydroxyfumarate) showed persistent differential expression at 1, 3, and 6 months follow-up. Some were found to be significantly associated with weight loss, insulin resistance improvement, and liver fat content reduction. Conclusions: This finding may provide a new perspective for revealing novel biomarkers and mechanisms of metabolic improvement in obesity and related comorbidities.

Research on enhancing the production of lipids, particularly polyunsaturated fatty acids that are considered important for health, has focused on improvement of metabolism as well as heterologous expression of biosynthetic genes in the oleaginous fungus Aspergillus oryzae. To date, the productivity and production yield of free fatty acids have been enhanced by 10-fold to 90-fold via improvements in metabolism and optimization of culture conditions. Moreover, the productivity of ester-type fatty acids present in triacylglycerols could be enhanced via metabolic improvement. Culturing A. oryzae in a liquid medium supplemented with non-ionic surfactants could also lead to the effective release of free fatty acids from the cells. The current review highlights the advancements made in this field so far and discusses the future outlook for research on lipid production using A. oryzae. I hope the contents are useful for researchers in this field to consider the strategy of increasing production of various valuable metabolites as well as lipids in A. oryzae.

Abstract Background and aim The role of dietary protein and glycemic index on insulin resistance (based on TyG index) within a nutritional program for weight loss and weight maintenance was examined. Methods This study analyzed 744 adults with overweight/obesity within the DIOGenes project. Patients who lost at least 8% of their initial weight (0–8 weeks) after a low-calorie diet (LCD) were randomly assigned to one of five ad libitum diets designed for weight maintenance (8–34 weeks): high/low protein (HP/LP) and high/low glycemic index (HGI/LGI), plus a control. The complete nutritional program (0–34 weeks) included both LCD plus the randomized diets intervention. The TyG index was tested as marker of body mass composition and insulin resistance. Results In comparison with the LP/HGI diet, the HP/LGI diet induced a greater BMI loss (p