Wheat germ supplementation has modest effects on gut health markers but improves glucose homeostasis markers in adults classified as overweight: A randomized controlled pilot study.

Wheat germ (WG), a by-product of flour milling, is rich in bioactive substances that may help improve health complications associated with increased adiposity. This study investigated the effects of WG on gut health, metabolic, and inflammatory markers in adults classified as overweight. We hypothesized that WG, because of its many bioactive components, would improve gut health and metabolic, and inflammatory markers in overweight adults. Forty adults (18-45 years old) and with a body mass index between 25 and 30 kg/m2 participated in this single-blinded randomized controlled pilot study. Participants consumed the study supplements containing 30 g of either cornmeal (control, CL) or WG daily for 4 weeks. Primary outcome variables were gut health markers including gut microbiota, gut integrity markers, and fecal short-chain fatty acids, whereas secondary outcome variables included metabolic and inflammatory parameters assessed at baseline and at the end of supplementation. Thirty-nine participants (n = 19 and 20 for CL and WG group, respectively) completed the study. The genus Faecalibacterium was significantly higher in the WG group compared to CL post-supplementation but no significant changes in other gut health markers, short-chain fatty acids, inflammatory markers, and lipid profiles were observed. Compared with baseline, WG improved markers of glucose homeostasis including insulin (P = .02), homeostatic model assessment of insulin resistance (P = .03), glycated hemoglobin (P = .07), and the pro-inflammatory adipokine, resistin (P = .04). However, these parameters after intervention were not different with control. Our findings suggest that WG supplementation have modest effects on gut health but may provide an economical option for individuals to improve glycemic control.

Fructooligosaccharides act on the gut-bone axis to improve bone independent of Tregs and alter osteocytes in young adult C57BL/6 female mice.

Targeting the gut-bone axis with probiotics and prebiotics is considered as a promising strategy to reduce the risk of osteoporosis. Gut-derived short chain fatty acids (SCFA) mediate the effects of probiotics on bone via Tregs, but it is not known whether prebiotics act through a similar mechanism. We investigated how 2 different prebiotics, tart cherry (TC) and fructooligosaccharide (FOS), affect bone, and whether Tregs are required for this response. Eight-wk-old C57BL/6 female mice were fed with diets supplemented with 10% w/w TC, FOS, or a control diet (Con; AIN-93M) diet, and they received an isotype control or CD25 Ab to suppress Tregs. The FOS diet increased BMC, density, and trabecular bone volume in the vertebra (~40%) and proximal tibia (~30%) compared to the TC and control diets (Con), irrespective of CD25 treatment. Both prebiotics increased (P < .01) fecal SCFAs, but the response was greater with FOS. To determine how FOS affected bone cells, we examined genes involved in osteoblast and osteoclast differentiation and activity as well as genes expressed by osteocytes. The FOS increased the expression of regulators of osteoblast differentiation (bone morphogenetic protein 2 [Bmp2], Wnt family member 10b [Wnt10b] and Osterix [Osx]) and type 1 collagen). Osteoclasts regulators were unaltered. The FOS also increased the expression of genes associated with osteocytes, including (Phex), matrix extracellular phosphoglycoprotein (Mepe), and dentin matrix acidic phosphoprotein 1 (Dmp-1). However, Sost, the gene that encodes for sclerostin was also increased by FOS as the number and density of osteocytes increased. These findings demonstrate that FOS has a greater effect on the bone mass and structure in young adult female mice than TC and that its influence on osteoblasts and osteocytes is not dependent on Tregs.

Reduced estrogen signaling contributes to bone loss and cardiac dysfunction in interleukin-10 knockout mice.

Characterization of the interleukin (IL)-10 knockout (KO) mouse with chronic gut inflammation, cardiovascular dysfunction, and bone loss suggests a critical role for this cytokine in interorgan communication within the gut, bone, and cardiovascular axis. We sought to understand the role of IL-10 in the cross-talk between these systems. Six-week-old IL-10 KO mice and their wild type (WT) counterparts were maintained on a standard rodent diet for 3 or 6 months. Gene expression of proinflammatory markers and Fgf23, serum 17ß-estradiol (E2), and cardiac protein expression were assessed. Ileal Il17a and Tnf mRNA increased while Il6 mRNA increased in the bone and heart by at least 2-fold in IL-10 KO mice. Bone Dmp1 and Phex mRNA were repressed at 6 months in IL-10 KO mice, resulting in increased Fgf23 mRNA (~4-fold) that contributed to increased fibrosis. In the IL-10 KO mice, gut bacterial ß-glucuronidase activity and ovarian Cyp19a1 mRNA were lower (p < 0.05), consistent with reduced serum E2 and reduced cardiac pNOS3 (Ser1119 ) in these mice. Treatment of ileal lymphocytes with E2 reduced gut inflammation in WT but not IL-10 KO mice. In conclusion, our data suggest that diminished estrogen and defective bone mineralization increased FGF23 which contributed to cardiac fibrosis in the IL-10 KO mouse.

Supplemental wheat germ modulates phosphorylation of STAT3 in the gut and NF-κBp65 in the adipose tissue of mice fed a Western diet.

Background: Commensal gut bacteria, including Lactobacillus, can produce metabolites that stimulate the release of gut antimicrobial peptides (AMPs) via the signal transducer and activator of transcription (STAT)3 pathway and prevent obesity-associated leaky gut and chronic inflammation. We have previously reported that wheat germ (WG) selectively increased cecal Lactobacillus in obese mice. Objectives: This study investigated the effects of WG on gut STAT3 activation and AMPs (Reg3γ and Reg3ß) as well as the potential of WG to inhibit nuclear Nf-κB-activation and immune cell infiltration in the visceral adipose tissue (VAT) of mice fed a Western diet (i.e., high-fat and sucrose diet [HFS]). Methods: Six-wk-old male C57BL/6 mice were randomly assigned to 4 groups (n = 12/group): control (C, 10% fat and sucrose kcal) or HFS (45% fat and 26% sucrose kcal) diet with or without 10% WG (wt/wt) for 12 wk. Assessments include serum metabolic parameters jejunal AMPs genes, inflammatory markers, and phosphorylation of STAT3 as well as VAT NF-κBp65. Independent and interaction effects of HFS and WG were analyzed with a 2-factor ANOVA. Results: WG significantly improved markers of insulin resistance and upregulated jejunal Il10 and Il22 genes. The HFS + WG group had a 15-fold increase in jejunal pSTAT3 compared with the HFS group. Consequently, WG significantly upregulated jejunal mRNA expression of Reg3γ and Reg3ß. The HFS group had a significantly higher VAT NF-κBp65 phosphorylation than the C group, while the HFS + WG group suppressed this to the level of C. Moreover, VAT Il6 and Lbp genes were downregulated in the HFS + WG group compared with HFS. Genes related to macrophage infiltration in the VAT were repressed in the WG-fed mice. Conclusion: These findings show the potential of WG to influence vital regulatory pathways in the gut and adipose tissue which may reduce the chronic inflammatory burden on these tissues that are important targets in obesity and insulin resistance.

Wheat Germ Supplementation Reduces Inflammation and Gut Epithelial Barrier Dysfunction in Female Interleukin-10 Knockout Mice Fed a Pro-Atherogenic Diet.

BACKGROUND: Mice lacking IL-10 are prone to gut inflammation. Additionally, decreased production of short-chain fatty acids (SCFAs) plays a significant role in the high-fat (HF) diet-induced loss of gut epithelial integrity. We have previously shown that wheat germ (WG) supplementation increased ileal expression of IL-22, an important cytokine in maintaining gut epithelial homeostasis. OBJECTIVES: This study investigated the effects of WG supplementation on gut inflammation and epithelial integrity in IL-10 knockout mice fed a pro-atherogenic diet. METHODS: Eight-week-old female C57BL/6 wild type mice were fed a control diet (10% fat kcal), and age-matched knockout mice were randomly assigned to 1 of 3 diets (n = 10/group): control, high-fat high-cholesterol (HFHC) [(43.4% fat kcal (∼49% saturated fat, 1% cholesterol)], or HFHC + 10% WG (HFWG) for 12 wk. Fecal SCFAs and total indole, ileal, and serum proinflammatory cytokines, gene or protein expression of tight junctions, and immunomodulatory transcription factors were assessed. Data were analyzed by 1-way ANOVA, and P < 0.05 was considered statistically significant. RESULTS: Fecal acetate, total SCFAs, and indole increased (P < 0.05) by at least 20% in HFWG compared with the other groups. WG increased (P < 0.0001, 2-fold) ileal Il22 (interleukin 22) to Il22ra2 (interleukin 22 receptor, alpha 2) mRNA ratio and prevented the HFHC diet-mediated increase in ileal protein expression of indoleamine 2,3 dioxygenase and pSTAT3 (phosphorylated signal transducer and activator of transcription 3). WG also prevented the HFHC diet-mediated reduction (P < 0.05) in ileal protein expression of the aryl hydrocarbon receptor and the tight junction protein, zonula occludens-1. Serum and ileal concentrations of the proinflammatory cytokine, IL-17, were lower (P < 0.05) by at least 30% in the HFWG group than in the HFHC group. CONCLUSIONS: Our findings demonstrate that the anti-inflammatory potential of WG in IL-10 KO mice consuming an atherogenic diet is partly attributable to its effects on the IL-22 signaling and pSTAT3-mediated production of T helper 17 proinflammatory cytokines.

Montmorencytart cherry supplementation improved markers of glucose homeostasis but has modest effects on indicators of gut health in mice fed a Western diet.

The gut microbiota plays an important role in the pathophysiology of obesity and type 2 diabetes. Emerging evidence suggests that anthocyanin-rich foods such as US Montmorency tart cherry (TC) can promote health by influencing the gut microbiota and maintaining gut integrity. This study investigated the effects of TC supplementation on the gut microbiota, markers of gut health, and metabolic parameters in mice fed a western diet (WD). Seventy-two C57BL/6 male mice were assigned to dietary treatments in a 2 × 3 factorial design with diet (control, WD) and TC (0, 5, 10% wt/wt) as factors. After 12 weeks of dietary treatment, tissues were collected to evaluate metabolic parameters and markers of gut health including cecal content microbiota and fecal short chain fatty acids (SCFAs). TC supplementation significantly increased the bacterial phylum, Actinobacteria, cecal weight, and fecal SCFAs and reduced the Proteobacteria and Deferribacteres phyla. However, gut histological parameters and expression of genes related to gut integrity were unaffected by TC. Body weight, serum cholesterol, triglyceride, leptin, plasminogen activator inhibitor-1 and resistin were increased with WD and TC had no effect on these parameters. Fasting blood glucose and the surrogate marker of insulin resistance, homeostatic model assessment of insulin resistance (HOMA-IR), was significantly increased by WD which was improved by TC particularly the 5% dose. In conclusion, TC supplementation, particularly the 5% dose, improved markers of glucose homeostasis but has modest effects on gut microbial population and SCFAs production. The mechanism by which TC improved markers of glucose homeostasis needs to be further investigated.

Pinto beans modulate the gut microbiome, augment MHC II protein, and antimicrobial peptide gene expression in mice fed a normal or western-style diet.

The onset of type 2 diabetes in obesity is associated with gut dysbiosis and a failure to confine commensal bacteria and toxins to the gut lumen while prebiotics may prevent these effects. This study evaluated the effects of pinto beans (PB) supplementation on cecal bacteria, short-chain fatty acids (SCFAs), distal ileal antigen presentation marker (major histocompatibility complex [MHC] II) and antimicrobial peptide genes during short-term high-fat, high sucrose (HFS) feeding. Six-week-old, male C57BL/6J mice were randomly assigned to four groups (n=12/group), and fed a control (C) or HFS diet with or without cooked PB (10%, wt/wt) for 30 days. Supplemental PB in both the C and HFS diets decreased the abundance of Tenericutes and the sulfate-reducing bacteria Bilophila. In contrast, PB raised the abundance of taxa within the SCFAs-producing family, Lachnospiraceae, compared to groups without PB. Consequently, fecal butyric acid was significantly higher in PB-supplemented groups compared to C and HFS groups. PB reversed the HFS-induced ablation of the distal ileal STAT3 phosphorylation, and up-regulated antimicrobial peptide genes (Reg3γ and Reg3ß). Furthermore, the expression of MHC II protein was elevated in the PB supplemented groups compared to C and HFS. Tenericutes and Bilophilia negatively correlated with activated STAT3 and MHC II proteins. Finally, supplemental PB improved fasting blood glucose, glucose tolerance and suppressed TNFα and inducible nitric oxide synthase mRNA in the visceral adipose tissue. Put together, the beneficial impact of PB supplementation on the gut may be central to its potential to protect against diet-induced inflammation and impaired glucose tolerance.

Taurine Ameliorates Thyroid Hypofunction and Renal Injury in L-NAME-Induced Hypertensive Rats.

There is a growing global interest in hypertension due to its associated complications including renal dysfunction in patients. The thyroid system reportedly regulates renal function in both animal and human. The present study investigated the therapeutic efficacy of taurine on renal and thyroid dysfunctions in hypertensive rats. Hypertension was induced by oral administration of nitric oxide synthase inhibitor, N-nitro L-arginine-methyl-ester (L-NAME), at 40 mg/kg body weight to the male Wistar rats for 14 consecutive days. The hypertensive rats were subsequently treated with either taurine (100 and 200 mg/kg) or reference drug atenolol (10 mg/kg) for another 14 consecutive days. Hypertensive rats showed renal damage evidenced by elevated plasma creatinine and urea levels when compared with normotensive control rats. Furthermore, L-NAME-induced hypertensive rats showed decreased circulatory concentrations of thyroid stimulating hormone, thyroxine, triiodothyronine and the ratio of triiodothyronine to thyroxine. The marked decrease in the renal antioxidant enzyme activities and nitric oxide level was accompanied by significant increase in myeloperoxidase activity and biomarkers of oxidative stress in hypertensive rats. Histological examination of kidneys from hypertensive rats revealed congestion of blood vessels, hemorrhagic lesion and disorganized glomerular structure. However, treatment with taurine or atenolol significantly reversed the suppression of thyroid function, ameliorated renal oxidative stress and histopathological lesions in L-NAME-induced hypertensive rats. Taurine may be a useful chemotherapeutic supplement in enhancing renal and thyroid functions in hypertensive patients.

Taurine enhances spermatogenic function and antioxidant defense mechanisms in testes and epididymis of L-NAME-induced hypertensive rats.

The beneficial health effects of taurine on hypertension have been demonstrated previously in both experimental and epidemiological studies. However, the role of taurine in reproductive dysfunction associated with hypertension has not been investigated. The present study evaluated the therapeutic efficacy of taurine on reproductive deficits in N-nitro-l-arginine methyl ester (L-NAME)-induced hypertensive rats. Sixty male Wistar rats were randomly assigned into six groups namely control, taurine alone, L-NAME alone (40mg/kg) or L-NAME treated with either taurine (100 and 200mg/kg) or reference drug atenolol (10mg/kg) for 28 consecutive days. Results indicated that taurine treatment significantly abrogated L-NAME-induced increase in systolic, diastolic and mean arterial pressures when compared with hypertensive control. Administration of taurine markedly increased antioxidant enzymes activities and glutathione level whereas it suppressed the increase in biomarkers of oxidative stress in the testes and epididymis of L-NAME-induced hypertensive rats. Moreover, taurine significantly reversed hypertension mediated decreases in circulatory concentrations of luteinizing hormone, follicle-stimulating hormone and testosterone whereas it increased testicular sperm number, epididymal sperm number and sperm progressive motility in the hypertensive rats. Furthermore, taurine abrogated the suppression of marker enzymes of testicular function namely acid phosphatase, alkaline phosphatase and lactate dehydrogenase and preserved the histo-architectures of the testes and epididymis in L-NAME-induced hypertensive rats. Taken together, the findings from this study highlight the beneficial role of taurine in reproductive system of L-NAME-induced male hypertensive rats. Taurine supplementation may be a good clinical approach to prevent reproductive deficits in male hypertensive patients.