Multigenerational effects of dietary macronutrient intake on the metabolic phenotype of male Wistar rats

Comparative digestive morphology and physiology of five species of Peromyscus under controlled environment and diet

Digestive morphology and physiology differ across animal species, with many comparative studies uncovering relationships between animal ecology or diet, and the morphology and physiology of the gastrointestinal tract. However, many of these studies compare wild-caught animals feeding on uncontrolled diets and compare broadly related taxa. Thus, few studies have disentangled the phenotypic consequences of genetics from those potentially caused by the environment, especially across closely related species that occupy similar ecological niches. Here, we examined differences in digestive morphology and physiology of five closely related species of Peromyscus mice that were captive bred under identical environmental conditions and identical diets for multiple generations. Using phylogenetic generalized least squares (PGLS) of species means to control for body size, we identified a phylogenetic signal in the mass of the foregut and length of the small intestine across species. As proportions of total gut mass, we identified phylogenetic signals in relative foregut and small intestine masses, indicating that the sizes of these structures are more similar among closely related species. Finally, we detected differences in activities of the protease aminopeptidase-N enzyme across species. Overall, we demonstrate fine-scale differences in digestive morphology and physiology among closely related species. Our results suggest that Peromyscus could provide a system for future studies to explore the interplay between natural history, morphology, and physiology (e.g. ecomorphology and ecophysiology), and to investigate the genetic architecture that underlies gut anatomy.

A high carbohydrate and soda diet influences metabolic variables in Wistar rats

AIMS

High carbohydrate diet and carbonated soda consumption have individually been associated with metabolic dysfunction, with links to glucose and insulin homeostasis, affecting metabolic variables associated with feeding, satiety and adiposity. Our objective is to determine the combined effect of a high carbohydrate and carbonated soda diet on metabolic variables in male and female Wistar rats.

MATERIALS AND METHODS

Thirty-two female and male weanlings were equally divided into four dietary groups; Control, Soda, High Carbohydrate diet (HCD), and High Carbohydrate diet/Soda (HCD/Soda), and fed ad libitum for fourteen weeks. Bodyweight, thoracic circumference, abdominal circumference and glucose was determined; Insulin, leptin, adiponectin, Tumor Necrotic Factor (TNF)-α, Interleukin (IL)-6 and lipid profile were assayed and used to determine the metabolic effects.

KEY FINDINGS

Soda and HCD/Soda had increased body weight in male rats, while HCD-fed rats were reduced compared to respective controls. Abdominal circumference, total cholesterol and reduced HDL of Soda were elevated in both sexes. Although HCD/Soda groups had elevated abdominal circumference in both sexes, total cholesterol and reduced high-density lipoprotein (HDL) were both reduced in females. Insulin and malondialdehyde (MDA) concentrations in Soda-fed rats was significantly reduced, however, MDA was elevated in both sexes in HCD and HCD/Soda fed rats. Female HCD and HCD/Soda groups had a significant increase in glutathione (GSH) concentration and a significant reduction in catalase. TNF-α was increased in both Soda and HCD/Soda groups.

SIGNIFICANCE

The results of this study suggest that HCD and Soda consumption results in alteration in phenotype and variables impacting metabolism.

Transgenerational effects of obesogenic diets in rodents: A meta-analysis

Obesity is a major health condition that affects millions worldwide. There is an increased interest in understanding the adverse outcomes associated with obesogenic diets. A multitude of studies have investigated the transgenerational impacts of maternal and parental obesogenic diets on subsequent generations of offspring, but results have largely been mixed. We conducted a systematic review and meta-analysis on rodent studies to elucidate how obesogenic diets impact the mean and variance of grand-offspring traits. Our study focused on transgenerational effects (i.e., F2 and F3 generations) in one-off and multigenerational exposure studies. From 33 included articles, we obtained 407 effect sizes representing pairwise comparisons of control and treatment grand-offspring groups pertaining to measures of body weight, adiposity, glucose, insulin, leptin, and triglycerides. We found evidence that male and female grand-offspring descended from grandparents exposed to an obesogenic diet displayed phenotypes consistent with metabolic syndrome, especially in cases where the obesogenic diet was continued across generations. Further, we found stronger evidence for the effects of grand-maternal than grand-paternal exposure on grand-offspring traits. A high-fat diet in one-off exposure studies did not seem to impact phenotypic variation, whereas in multigenerational exposure studies it reduced variation in several traits.

High-Fat Diet Induced Gut Microbiota Alterations Associating With Ghrelin/Jak2/Stat3 Up-Regulation to Promote Benign Prostatic Hyperplasia Development

The role of high-fat diet (HFD) induced gut microbiota alteration and Ghrelin as well as their correlation in benign prostatic hyperplasia (BPH) were explored in our study. The gut microbiota was analyzed by 16s rRNA sequencing. Ghrelin levels in serum, along with Ghrelin and Ghrelin receptor in prostate tissue of mice and patients with BPH were measured. The effect of Ghrelin on cell proliferation, apoptosis, and induction of BPH in mice was explored. Our results indicated that BPH mice have the highest ratio of Firmicutes and Bacteroidetes induced by HFD, as well as Ghrelin level in serum and prostate tissue was significantly increased compared with control. Elevated Ghrelin content in the serum and prostate tissue of BPH patients was also observed. Ghrelin promotes cell proliferation while inhibiting cell apoptosis of prostate cells. The effect of Ghrelin on enlargement of the prostate was found almost equivalent to that of testosterone propionate (TP) which may be attenuated by Ghrelin receptor antagonist YIL-781. Ghrelin could up-regulate Jak2/pJak2/Stat3/pStat3 expression in vitro and in vivo. Our results suggested that Gut microbiota may associate with Ghrelin which plays an important role in activation of Jak2/Stat3 in BPH development. Gut microbiota and Ghrelin might be pathogenic factors for BPH and could be used as a target for mediation.