0
selected
-
1.
The Role of Gut Hormones in Diet-Induced Weight Change: A Systematic Review.
Zhao, X, Han, Q, Gang, X, Lv, Y, Liu, Y, Sun, C, Wang, G
Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme. 2017;(11):816-825
Abstract
Gut hormones are known to play an important role in long-term weight loss maintenance after bariatric surgery. However, the interplay between gut hormones and diet-induced weight changes remains unclear. Our aims were to evaluate the alterations of gut hormones in diet-induced weight loss, weight maintenance, and weight regain periods. Available studies were searched on MEDLINE, EMASE, ClinicalTrials.gov, the Cochrane Library, and Web of science from inception to October 2016. After selection, 16 studies with 656 participants were included. Based on current evidence, we found significant alterations of gut hormones induced by different diets. In weight-loss diets, decreased fasting total PYY, GLP-1, CCK, GIP, PP, and amylin along with increased ghrelin levels were observed in most studies. After weight loss, the persistent decreases of fasting total PYY and GLP-1 levels as well as increased appetite were reported, suggesting the profound impact of altered gut hormones on later weight regain after dietary intervention. The differences between diet-induced changes in gut hormones and other treatments such as bariatric surgery and exercise are also discussed in this review. Although significant alterations of gut hormones were found during weight changes, huge heterogeneity exists in methods and populations. More large-scale studies with elaborate design addressing the gut hormone alterations in dietary weight regulation are required in the future.
-
2.
Comparative effects of intraduodenal amino acid infusions on food intake and gut hormone release in healthy males.
Steinert, RE, Ullrich, SS, Geary, N, Asarian, L, Bueter, M, Horowitz, M, Feinle-Bisset, C
Physiological reports. 2017;(21)
Abstract
In contrast to the many studies of the effects of individual amino acids (AAs) on eating, no studies have compared the effects of different AAs on eating and underlying preabsorptive gastrointestinal mechanisms. To compare the effects of intraduodenal infusions of l-tryptophan (TRP), l-leucine (LEU), l-phenylalanine (PHE) and l-glutamine (GLN) on appetite, gastrointestinal hormone responses (including ghrelin, cholecystokinin (CCK), peptide YY (PYY) and glucagon-like peptide-1 [GLP-1]), glycemia (glucagon, insulin and glucose) and test meal size in healthy males, we retrospectively analyzed data from four published independent, randomized, double-blind, placebo-controlled studies of 90-min intraduodenal infusions of the individual AAs. The designs of the studies were identical, except the dose of TRP (0.15 kcal/min) was lower than that of the other AAs (0.45 kcal/min) because higher doses of this AA were not well tolerated. TRP and LEU decreased intake more than PHE (reductions relative to control, ~219 ± 68, ~170 ± 48 and ~12 ± 57 kcal, respectively), and TRP decreased intake more than GLN (~31 ± 82 kcal). These effects of TRP and LEU versus GLN, but not versus PHE, were paralleled by greater decreases in plasma ghrelin, and increases in CCK, concentrations. TRP increased PYY more than GLN or LEU, but not PHE. LEU increased PYY less than PHE. No significant differences were detected for GLP-1. PHE increased glucagon more than TRP or LEU, and increased insulin more than TRP. Under our experimental conditions, intraduodenal TRP and LEU were more satiating than PHE and GLN. The greater satiating efficacy of LEU versus PHE was significantly dissociated from the effects of these AAs on PYY, while the greater satiating potency of TRP versus PHE was significantly dissociated from the effects of these AAs on insulin and glucagon. In contrast, ghrelin and CCK, and potentially other mechanisms, including central sensing of individual AAs, appear to be stronger candidate mechanisms for the relative satiating effects obtained.
-
3.
Systematic review and meta-analysis of the effect of meal intake on postprandial appetite-related gastrointestinal hormones in obese children.
Nguo, K, Walker, KZ, Bonham, MP, Huggins, CE
International journal of obesity (2005). 2016;(4):555-63
Abstract
UNLABELLED Understanding the physiological response to meal intake, of gut-derived appetite and satiety hormone signals, in obese compared with healthy-weight children may assist with informing strategies to help curtail the obesity epidemic. A systematic review and meta-analysis of studies investigating the acute postprandial response of gastrointestinal appetite hormones to meal intake in obese children was undertaken. Systematic searches of databases EMBASE, CINAHL Plus, OVID Medline and the Cochrane Library were performed. INCLUSION CRITERIA a randomised controlled trial or experimental cross-sectional study following an acute test meal protocol with pre- and postprandial analysis of plasma or serum gastrointestinal hormone concentrations. Database searching retrieved 1001 papers for review. Nine studies met the inclusion criteria, collectively reporting on six appetite hormones yielding a total of 32 test meal-hormone comparisons. Meta-analyses compared the pooled estimate of the mean difference of the postprandial change in total ghrelin and total peptide YY (PYY). Obese compared with healthy-weight children had an attenuated change in ghrelin at 60 min (N=5 studies; n=129 participants) and 120 min postprandial (N=4 studies; n=100 participants) (P<0.05 for both time points). Obese compared with healthy-weight children also had an attenuated PYY response at 60 min (N=5 studies; n=128 participants) and 120 min postprandial (N=4 studies; n=100 participants). Insufficient studies reported on the postprandial time course of other appetite-related hormones, precluding a meta-analysis. Limited evidence notwithstanding, these findings indicate that PYY and ghrelin responses to a meal may be altered in obese children. This review has also identified a major gap in knowledge of hormonal appetite responses in childhood obesity. More comprehensive investigations of the homoeostatic regulation of gut-derived appetite and satiety hormone signals with behavioural and clinical outcomes are warranted to understand if there are consequences of these differences.
-
4.
Transcriptomic Analysis and Meta-Analysis of Human Granulosa and Cumulus Cells.
Burnik Papler, T, Vrtacnik Bokal, E, Maver, A, Kopitar, AN, Lovrečić, L
PloS one. 2015;(8):e0136473
Abstract
Specific gene expression in oocytes and its surrounding cumulus (CC) and granulosa (GC) cells is needed for successful folliculogenesis and oocyte maturation. The aim of the present study was to compare genome-wide gene expression and biological functions of human GC and CC. Individual GC and CC were derived from 37 women undergoing IVF procedures. Gene expression analysis was performed using microarrays, followed by a meta-analysis. Results were validated using quantitative real-time PCR. There were 6029 differentially expressed genes (q < 10-4); of which 650 genes had a log2 FC ≥ 2. After the meta-analysis there were 3156 genes differentially expressed. Among these there were genes that have previously not been reported in human somatic follicular cells, like prokineticin 2 (PROK2), higher expressed in GC, and pregnancy up-regulated nonubiquitous CaM kinase (PNCK), higher expressed in CC. Pathways like inflammatory response and angiogenesis were enriched in GC, whereas in CC, cell differentiation and multicellular organismal development were among enriched pathways. In conclusion, transcriptomes of GC and CC as well as biological functions, are distinctive for each cell subpopulation. By describing novel genes like PROK2 and PNCK, expressed in GC and CC, we upgraded the existing data on human follicular biology.
-
5.
Effects of chewing on appetite, food intake and gut hormones: A systematic review and meta-analysis.
Miquel-Kergoat, S, Azais-Braesco, V, Burton-Freeman, B, Hetherington, MM
Physiology & behavior. 2015;:88-96
Abstract
OBJECTIVES To seek insights into the relationship between chewing, appetite, food intake and gut hormones, and to consider potentially useful recommendations to promote benefits of chewing for weight management. MATERIALS AND METHODS Papers were obtained from two electronic databases (Medline and Cochrane), from searches of reference lists, and from raw data collected from the figures in the articles. A total of 15 papers were identified that detailed 17 trials. All 15 papers were included in the systematic review; however, a further five studies were excluded from the meta-analysis because appropriate information on hunger ratings was not available. The meta-analysis was conducted on a total of 10 papers that detailed 13 trials. RESULTS Five of 16 experiments found a significant effect of chewing on satiation or satiety using self-report measures (visual analogue scales, VASs). Ten of 16 experiments found that chewing reduced food intake. Three of five studies showed that increasing the number of chews per bite increased relevant gut hormones and two linked this to subjective satiety. The meta-analysis found evidence of both publication bias and between study heterogeneity (IA(2) = 93.4%, tau(2) = 6.52, p < 0.001) which decreased, but remained, when covariates were considered. Analysis of the heterogeneity found a substantial effect of the fasting period where the duration of fasting influenced the decrease in hunger due to chewing. Prolonged mastication significantly reduces self-reported hunger levels (hunger: − 2.31 VAS point, 95% CI [− 4.67, − 1.38], p < 0.001). CONCLUSIONS Evidence currently suggests that chewing may decrease self-reported hunger and food intake, possibly through alterations in gut hormone responses related to satiety. Although preliminary, the results identify a need for additional research in the area. Focused, uniform, experimental designs are required to clearly understand the relationships that exist between mastication, appetite, satiety, food intake and, ultimately, body weight.