Reem Sallam
Professor; Department of Medical Biochemistry, Faculty of Medicine, AinShams University
Professor of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Galala University, Suez, Egypt.
Reem Sallam has earned her Ph.D. in Biochemistry from the College of Medicine, University of Vermont, Burlington, Vermont, USA. She is currently a Professor of Medical Biochemistry & Molecular Biology, Faculty of Medicine, both in Galala University and in Ain Shams University in Egypt, and is a certified clinical nutritionist. She is supervising post-graduate students, is a certified TOT, and is a lead TA in IBT and AGMT courses organized by H3Africa. Reem has co-authored several articles in the field of bioinformatics, precision medicine, obesity, and metabolic diseases. She has also participated in writing the Saudi Clinical Practice Guideline for the Management of Overweight and Obesity in Adults. Her areas of research include the cellular, molecular and biochemical bases of obesity and associated diseases, the hemostatic & fibrinolytic abnormalities as a base for cardiovascular system-related complications, and the nutritional basis of metabolic diseases
Abstract
Background, aims, and hypothesis: Gut microbiota can potentially affect host body weight through their mediators, as short-chain fatty acids (SCFAs) and lipopolysaccharide (LPS). Therefore, the aim of this study was to assess the diet-associated changes in SCFAs, LPS and related downstream mediators, peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC1α) and hypoxia-inducible factor 1 alpha (HIF1α). We hypothesized that consumed diet might be corresponding to serum levels of SCFAs and LPS and accompanied with analogous changes in their downstream effectors.
Methods: Dietary intake of 31 participants was evaluated using 24-h recall, food frequency questionnaire and a Mediterranean diet scale (MDS). Serum SCFAs and LPS levels were estimated using gas chromatography-mass spectrometry and ELISA, respectively. PGC1α and HIF1α gene expression in Peripheral Blood Mononuclear Cells was detected by Real time quantitative polymerase chain reaction.
Results: Lean subjects showed higher dietary-fiber intake, MDS scores, propionate levels, PGC1α and HIF1α expression (P < 0.05). Propionate levels were positively correlated with MDS scores (P < 0.05), daily fiber intake, and PGC1α mRNA (P < 0.01). Relative expression levels of PGC1α and HIF1α were positively correlated (P < 0.05). LPS levels were higher in subjects with obesity compared to lean subjects (P < 0.01) and positively correlated with daily fat intake (P < 0.05).
Conclusions: Subjects consuming diet closer to Mediterranean diet had higher levels of serum propionate and PGC1α mRNA. Furthermore, the up-regulated expression of PGC1α and HIF1α might work together in favoring energy expenditure and reducing body weight.