Pulse Supplementation Improves Gut Health and Lowers Total Cholesterol in Postmenopausal Women

Objectives

Menopause is associated with many physiological changes as well as increased risk of obesity, cardiovascular disease, type 2 diabetes, and gut-related diseases (i.e. irritable bowel syndrome, inflammatory bowel disease, colon cancer). Data regarding the use of pulse crops in alleviating health risks associated with menopause are limited. This study investigated the effects of pulse supplementation on markers of gut health and metabolic outcomes in postmenopausal women.

Methods

Thirty-five postmenopausal (≥1 year without menstruation) women, ages 45–70 years old, who were not on hormone replacement therapy, probiotics, antibiotics, multiple supplements, or medications that affect lipids or glucose, were recruited for this clinical study. Study participants were asked to consume 100 g of pulses (alternate between chickpeas, kidney beans, pinto beans, black-eyed peas, and lentils) daily for 12 wks, and to maintain their normal diet and lifestyle. Anthropometric measures including body composition by dual-energy X-ray absorptiometry, plasma lipids and glucose, fecal short chain fatty acids (SCFAs), and stool characteristics (Bristol Stool Chart and the Cleveland Clinic Constipation Scoring System) were assessed before and at the end of 12-wk supplementation. P < 0.05 was considered statistically significant.

Results

There were no differences in anthropometric measures and plasma glucose at the end of the 12-wk supplementation compared to baseline. However, a reduction in plasma total cholesterol (p = 0.039) and LDL-C (p = 0.026), but an increase in both VLDL-C (p = 0.031) and triglycerides (p = 0.033) were observed with pulse supplementation. Constipation score significantly improved (p = 0.003) but no change in stool quality were observed with pulse supplementation. Fecal acetic acid (p< 0.001), n-butyric (p = 0.038), n-caproic (p = 0.004) and total SCFAs (p = 0.001) were also significantly increased with pulse supplementation.

Conclusions

Our findings demonstrate that 12 wks of pulse supplementation improved markers of gut health and lowers total- and LDL-cholesterol in postmenopausal women. This population who are at an increased risk for cardiovascular and gut-related diseases can benefit from regularly consuming pulses.

Funding Sources

USDA Award Pulse Crop Health Initiative (#58-3060-0-048) and the Jim and Lynn Williams Professorship

Wheatgerm Supplementation Reduces Gut Inflammation and Epithelial Barrier Dysfunction in IL-10 KO Mice Fed Atherogenic Diet

Objectives

Wheat germ (WG) contains many bioactive compounds with the potential to maintain an anti-inflammatory gut environment. This study investigated the effects of WG supplementation on gut inflammation and integrity in high-fat fed interleukin (IL)-10 KO mice.

Methods

Eight-wk-old female B6.129P2-Il10tm1Cgn/J (IL-10KO) and C57BL/6 (WT) mice (n = 10/group) were randomly assigned to diets: WT fed a control diet (WTCO; AIN93-M) and IL-10 KO mice fed control (KOCO), high-fat with high-cholesterol (HFHC; 45% fat kcal, 1% cholesterol), or HFHC + 10% WG (HFWG) for 3 m. Disease activity indices (fecal blood, ruffled fur, stool softness, and rectal prolapse) were monitored twice a week. Fecal indole and short chain fatty acids (SCFAs) concentration were assessed at the beginning and end of study. Proinflammatory cytokines were assessed in the serum and ileum. Ileal and colonic protein expression of transcription factors (STAT3, p-STAT3, PPARg, FoxP3, and AhR), tight junction proteins (ZO-1, occludin), and tryptophan catabolizing enzyme (IDO-1) were assessed by immunoblotting. Relative ileal and colonic gene expression of IL-22 and antimicrobial peptides (Reg3b and Reg3g) were assessed using qRT-PCR. P &lt; 0.05 was considered statistically significant.

Results

WG increased (P = 0.003) colon length compared to the HFHC group. Weight loss (12.2% in HFHC vs WTCO) was not prevented by WG, but disease activity indices were significantly reduced in the WG vs HFHC group. WG also increased fecal indole, total SCFAs and acetate accompanied by an increase in colonic protein expression of PPARg (P &lt; 0.0001) and FoxP3 (P = 0.001). Ileal STAT3 phosphorylation was reduced (P = 0.0076) due to WG supplementation. An increased colon and ileal protein expression of IDO-1 in the HFHS group was reduced by WG, while also increasing the expression of AhR, ZO-1, and occludin. The relative gene expression of the antimicrobial peptides (Reg3b and Reg3g) was increased (P &lt; 0.05) while serum and ileal tissue concentration of the proinflammatory cytokine, IL-17 was reduced (P = 0.0165 and p = 0.0248 respectively) by WG.

Conclusions

WG modulated changes that are associated with HF-feeding in IL-10 KO mice, and might be a promising regimen for ameliorating the effects of gut inflammation.

Funding Sources

Oklahoma Agriculture Experiment Station, Jim and Lynn Williams Professorship, and Barbara K. Pass Grant.

Wheat Germ Supplementation Improves Glucose Homeostasis Markers of Overweight Adults Independent of Gut Microbial Modulation

Objectives

This study investigated the effects of wheat germ (WG) supplementation on inflammation, metabolic, and gut health markers in overweight adults.

Methods

Forty overweight (BMI = 25.0–30 kg/m2) adults between 18–45 y old were recruited to this single-blinded randomized placebo-controlled study. Qualified participants were asked to maintain their normal diet and physical activity and consume energy balls containing 30 g of either WG or cornmeal (control) daily for 4 wks. Anthropometric and metabolic parameters, as well as dietary (3-d food record), medical history, physical activity (Yale Physical Activity Survey), stool measures (Bristol Stool Chart and the Cleveland Clinic Constipation Scoring System), gut integrity markers, and fecal bacterial population were assessed at baseline and at the end of the supplementation period.

Results

Thirty-nine participants completed the 4-week study (n = 20 and 19 for the WG and control group, respectively). There were no differences in the lipid profile, but glycated hemoglobin (P = 0.04), insulin (P = 0.03), and homeostatic model assessment of insulin resistance (HOMA-IR; P = 0.04) were significantly decreased in the WG but not the control group. Similarly, the adipokine resistin was also significantly reduced (P = 0.03) by WG but not the control. There were no changes in stool characteristics between the two groups before and after supplementation. Similarly, there were no changes in gut bacterial population due to WG supplementation but the phyla Bacteroidetes (P = 0.03) and Proteobacteria (P = 0.048) and the genus Bacteroides (P = 0.03) were significantly decreased in the control group. No significant changes were observed in plasma inflammatory markers, fecal short-chain fatty acid (SCFA) concentrations, and markers of gut integrity in both groups.

Conclusions

Four weeks of WG supplementation improved markers of glucose homeostasis, which can partly be attributed to the reduction of the pro-inflammatory adipokine resistin and not due to changes within the gut (i.e., bacterial population, gut integrity markers, and SCFA production). Our findings indicate that WG may be a safe, effective, and economical approach to improve glucose homeostasis.

Funding Sources

USDA Award #2019–67,018-29,260 and the Jim and Lynn Williams Professorship.

Montmorency Tart Cherry Supplementation Has Modest Effects on the Gut Microbiome and Markers of Gut Integrity and Insulin Resistance in Mice Fed Western Diet

Objectives

This study investigated the dose-dependent effects of freeze-dried Montmorency tart cherry (TC) supplementation on gut health and metabolic parameters in mice fed a western diet (WD).

Methods

Six-week-old male C57BL/6 mice were randomly assigned to dietary treatment groups in a 2 × 3 factorial design with diet (control [AIN-93M] or WD, 45% fat kcal and 26% sucrose kcal) and TC (0, 5, 10% wt/wt) as factors for 12 wks. At the end of dietary treatment, body composition was assessed by dual energy xray absorptiometry, and tissues were collected to evaluate metabolic parameters and markers of gut health. Cecal content was used for bacterial and short chain fatty acid analyses (SCFAs).

Results

TC at the 10% dose significantly increased the abundance of the beneficial bacterial phylum, Actinobacteria, relative to the unsupplemented groups (P = 0.018 and 0.010 vs control and WD, respectively). Relative cecal weight (P = 0.007) and SCFAs were significantly increased (P &lt; 0.05) with TC supplementation (∼20% and 2-fold for relative cecal weight and SCFAs, respectively). Histological evaluation revealed reduced ileal villi height (P = 0.0348), width (P = 0.0042) and area (P = 0.0132) with WD, and TC did not alter this response. Overall, the expression of genes related to gut health (i.e barrier integrity marker, mucus layer formation, and inflammatory marker), were unaffected by both WD and TC supplementation. Body weight (P = 0.0012), fat mass (P = 0.007), fasting blood glucose (P = 0.001), serum total cholesterol (P &lt; 0.0001), triglyceride (P = 0.002), leptin (P = 0.0011), plasminogen activator inhibitor 1 (P = 0.0344), and resistin (P = 0.0012) were increased with WD, and TC had no effect on these parameters. Despite modest effects on metabolic parameters, the homeostatic model assessment of insulin resistance, HOMA-IR, a commonly used tool for assessing insulin resistance, was improved by 50% with the 5% TC (P = 0.0003).

Conclusions

TC supplementation restored some beneficial bacteria and increased SCFAs altered by WD. However, these changes in the gut did not translate to improvement in metabolic outcomes except for HOMA-IR. The mechanism by which TC improves HOMA-IR needs to be investigated in future studies.

Funding Sources

Cherry Marketing Institute and the Jim and Lynn Williams Professorship.

Interleukin (IL)-10 Is Important in the Maintenance of Trabecular and Cortical Bone and Protects Against Western Diet-Induced Disruption in Bone Remodeling in Mice

Objectives

The purpose of this study was to investigate if consumption of a western diet (WD) exacerbates the effects of loss of function of IL-10, an anti-inflammatory cytokine, on biomarkers of bone metabolism and microarchitecture.

Methods

Six-week-old male B6.129P2-Il10tm1Cgn/J (IL-10 KO) and C57BL/6 mice (WT) were randomized to treatment in a 2 × 2 factorial with diet (AIN-93 control diet CD vs WD) and strain (IL-10 KO vs WT) as factors. Due to potential influence of high fat on intestinal Ca absorption, a WD diet with added Ca (1.2 g/kg) was used. After 12 wks, whole body dual-energy x-ray absorptiometry scans were performed to assess bone density and body composition, and micro-computed x-ray tomography was used to evaluate trabecular and cortical bone microarchitecture in the femur and lumbar vertebra. Serum biomarkers of bone formation, procollagen 1 intact N-terminal propeptide (P1NP), and resorption, c-terminal telopeptide of type I collagen (CTX-1) were assessed.

Results

Body weight, but not % body fat, was lower (P &lt; 0.05) in IL-10 KO mice relative to WT controls. 12 weeks of WD increased (P &lt; 0.05) body weight and % fat, but the response was not as great in the IL-10 KO mice. Bone mineral density and content were lower in IL-10 KO mice compared to WT, and the WD had no effect on these parameters. The IL-10 KO mice exhibited a decrease in trabecular bone volume, thickness, and number, and an increase in trabecular separation and structure model index compared to WT mice within the femur and vertebrae. The WD had no effect on these trabecular bone parameters. Cortical bone thickness and area were reduced (P &lt; 0.05) and porosity increased in both the femur and vertebra of IL-10 KO mice relative to their WT counterparts. This strain effect was not altered by the WD. IL-10 KO mice exhibited a significantly lower serum PINP and higher CTX-1 compared to the WT mice. Despite the lack of structural changes in bone after 12 wks, the WD increased (P &lt; 0.05) CTX-1 and tended to suppress P1NP (P = 0.051) in the IL-10 KO mice compared to WT.

Conclusions

We conclude that IL-10 plays an important role in bone metabolism and maintaining structural properties and in the absence of IL-10, WD negatively affects both osteoclast and osteoblast activity. Further studies are warranted to determine if structural changes occur with longer exposure to WD.

Funding Sources

Oklahoma Agricultural Experiment Station.

Understanding How Sex Influences the Impact of IL-10 on Bone Microarchitecture and Bone Metabolism Over Time

Objectives

Dietary interventions with pre- and probiotics favorably affect the gut-bone axis, mediated in part by the anti-inflammatory cytokine, interleukin (IL)-10. This study sought to understand how IL-10’s impact on bone metabolism and microarchitecture differs with sex and time.

Methods

Six-week-old B6.129P2-Il10tm1Cgn/J (KO) and C57BL/6 (WT) mice were assigned in a 2 × 2 × 2 factorial design with strain (WT & KO), sex, and time (3 & 6 m) as factors. Mice were fed AIN-93G diet for 3 m followed by AIN-93 M for the study duration. Dual-energy x-ray absorptiometry was used to assess bone mineral content (BMC) and density (BMD). Micro-computed tomography was used to assess femur and lumbar vertebrae trabecular and cortical bone. Serum procollagen 1 intact N-terminal propeptide (P1NP) and C-terminal telopeptide of type I collagen (CTX-1), bone formation and resorption markers respectively, were assessed by ELISA. Data were analyzed using ANOVA; p &lt; 0.05 was considered significant.

Results

Reductions in BMC and BMD (P &lt; 0.05) in KO vs WT and at 3 vs 6 m were observed; a sex effect was found with reductions in BMC in KO females compared to KO males. Femoral trabecular bone volume (BV/TV) was lower (P &lt; 0.05) in KO vs WT, females vs males, and at 6 vs 3 m. Trabecular thickness (TbTh) decreased (P &lt; 0.05) in KO vs WT and increased from 3 to 6 m, while decreases in trabecular number (TbN) were greater (P &lt; 0.05) in KO mice, females, and at 6 m compared to counterparts. Cortical area and thickness were decreased (P &lt; 0.05) in KO vs WT and in females vs males, which was greater at 6 m, while cortical bone porosity was higher in KO vs WT and increased at 6 mo. Vertebral trabecular BV/TV was lower (P &lt; 0.05) in KO vs WT at 3 and 6 m, with KO females showing reduced BV/TV (P &lt; 0.05) from 3 to 6 m. Reduced TbTh and TbN were observed in KO vs WT, and females had increased (P &lt; 0.05) TbTh and trabecular separation and reduced TbN. P1NP showed a time effect (P &lt; 0.05) with reductions in WT females and males at 6 m compared to 3 m KO females (P &lt; 0.05). CTX-1 shows a sex effect (P &lt; 0.05) and a trending strain effect (P = 0.059), with elevated serum CTX-1 in 3 m KO males compared to WT and KO females at 6 m (P &lt; 0.05).

Conclusions

While IL-10 plays an important role in maintaining both trabecular and cortical bone, it may have a more protective effect on the cortical bone of female mice over time.

Funding Sources

Oklahoma Agricultural Experiment Station.

Effects of Wheat Germ and Its Combination With Antibiotics on Metabolic and Gut Health Outcomes in Western Diet-Fed Mice

Objectives

This study evaluated whether wheat germ (WG) alone or in combination with antibiotics (Ab) will ameliorate metabolic and gut integrity and inflammatory markers in mice fed a Western diet (WD).

Methods

Six-wk-old male C57BL/6 mice were randomly assigned (n = 7–8/group) to three dietary treatement groups: WD (60% fat kcal), WD + WG (10% wt/wt) and WD + WG + Ab (1 mg/mL ampicillin, metronidazole, neomycin, and ampothericin B plus 0.5 mg/mL vancomycin cocktail added in drinking water) for 4 wks. Food intake and body weights were assessed daily throughout the study. Tissues were collected and assessments included clinical chemistry parameters, intaperitoneal glucose tolerance test (IPGTT), body composition by dual-energy x-ray absorptiometry, and gut integrity and inflammatory markers by qPCR. Effects of treatment were analyzed with one-way ANOVA using SPSS software and P &lt; 0.05 was considered significant.

Results

Food intake differed significantly (P &lt; 0.0001) between groups, with the WD + WG having the highest and WD + WG + Ab having the lowest intake. Final body weight (P &lt; 0.0001) and fat mass (P &lt; 0.0001) was lowest in the WD + WG + Ab and similar for WD and WD + WG groups. There was no difference in lean mass among the groups. IPGTT area under the curve (P &lt; 0.0001) and serum total cholesterol (P = 0.023) were significantly reduced and fasting glucose tended (P = 0.091) to be lower in the WD + WG + Ab group. Mice in the WD + WG + Ab group also had higher cecal tissue and cecal content weights (P &lt; 0.0001) as well as the ileal gene expression of the tight junction protein occludin (P = 0.008) compared to the other groups. On the other hand, WD + WG fed mice had significantly higher ileal gene expression of the anti-inflammatory cytokine, interleukin (IL)-10, compared to WD (P = 0.05) and WD + WG + Ab (P = 0.035).

Conclusions

Although WG alone promoted a gut anti-inflammatory response, it was not as effective as the combination of WG and antibiotics at improving metabolic outcomes. These positive effects of WD + WG + Ab on metabolic outcomes were likely due to a reduction in food intake resulting in lower body weight and body fat. Future studies should investigate the contribution of antibiotics, the role of the gut microbiota, and the impact of long-term antibiotic use.

Funding Sources

Oklahoma Agriculture Experiment Station and the Jim and Lynn Williams Professorship.

Loss of Interleukin (IL)-10 Is Associated With Increased Vascular Inflammation and Sex-Differences in Metabolic Outcomes of Normal Diet-Fed Mice

Objectives

The anti-inflammatory cytokine, IL-10, plays an important role in reducing the risk of many inflammatory diseases. This study investigated the time and sex effects of IL-10 gene deletion on metabolic risk factors that contribute to the development of cardiovascular disease.

Methods

Six-wk-old male and female B6.129P2-Il10tm1Cgn/J (IL-10−/−) and C57BL/6 (WT) mice (n = 12–16/group) were randomly assigned to 12- or 24-wk time points and were fed growth (AIN-93G) diet up to 3 m of age and then maintenance diet (AIN-93M) for the remainder of the study. Monthly fasting glucose was assessed as well as intraperitoneal glucose tolerance test (ipGTT), body composition, and serum metabolic parameters at each study end point. Cardiac and vascular adhesion molecules, macrophage marker F4/80, and sterol metabolism genes were assessed using qPCR. Data were analyzed using t-test and 2-way ANOVA with strain and gender as factors, and α = 0.05.

Results

IL-10 deletion resulted in weight loss (p &lt; 0.05) coinciding with reduced fat mass and % fat (P &lt; 0.05) in both sexes of IL-10−/−. Loss of IL-10 had no effect on fasting glucose at any time point in either sex; however, a delayed response to glucose challenge and increased AUC with the ipGTT (P &lt; 0.05) occurred in male IL-10−/− vs WT mice. No strain effect was observed on serum lipids at 12 wks, but cholesterol and high-density lipoprotein (HDL)-C were reduced (P &lt; 0.05) in IL-10−/− vs WT mice at 24 wks. Only male IL-10−/− mice exhibited elevated (P &lt; 0.05) non-HDL cholesterol and tended (P = 0.072) to have elevated triglycerides vs WT mice at 24 wks. In conjunction with serum lipid changes, male IL-10−/− mice increased (P &lt; 0.05) hepatic transcription of β-hydroxy β-methylglutaryl-CoA (HMG-CoA), whereas HMGCoA transcript tended to be repressed (≥ −53.5%; P = 0.08) in female IL-10−/− vs WT mice. At 12 and 24 wks, IL-10−/− exhibited increased (P &lt; 0.05) circulating c-reactive protein and aortic and cardiac gene expression of VCAM-1, ICAM-1, and iNOS. The only increase in the F4/80 macrophage marker occurred in male IL-10−/− mice vs WT at 24 wks.

Conclusions

Loss of IL-10 was associated with different metabolic responses in male and female mice and could be detrimental to cholesterol-mediated metabolic processes in female mice on a control diet.

Funding Sources

Oklahoma Agriculture Experiment Station and the Jim and Lynn Williams Professorship.

Supplemental Wheat Germ Activates the STAT3-Reg3 Pathway in the Gut and Attenuates the Lipopolysaccharide Binding Protein Gene in the Adipose Tissue of Mice Fed a Western Diet

Objectives

This study investigated the effects of wheat germ (WG) on gut antimicrobial peptides (AMPs, i.e., regenerating islet-derived protein [Reg] 3 g and Reg3b) in the jejunum and its potential to inhibit nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) activation and immune cell infiltration in the visceral adipose tissue (VAT) of mice fed a control or a western diet (i.e., high fat and high sucrose, HFS).

Methods

Six-wk-old male C57BL/6 mice were randomly assigned to four groups (n = 12/group), and fed a control (C, 10% kcal fat, 10% kcal sucrose) or HFS (45% kcal fat, 26% kcal sucrose) diet with or without 10% WG (wt/wt) for 12 wks. Metabolic parameters were quantified in the serum. Phosphorylation of STAT3 in the jejunum and NF-kB activation in the VAT were assessed by immunoblotting. Gut antimicrobial peptide genes, and macrophage and inflammatory markers were measured by qPCR.

Results

After 12 wks of dietary treatment, WG significantly improved hyperglycemia, fasting insulin, and homeostatic model assessment of IR (HOMA-IR) by at least 17% (P ≤ 0.0034) in HFS-fed mice. Protein expression of the pore-forming claudin-2 was elevated in the jejunum of HFS-fed mice (≥101%; P = 0.0016). Supplemental WG upregulated Il-10 and Il-22 genes in the jejunum (≥116%; P ≤ 0.035). The HFS + WG group had a 15-fold increase (P = 0.0012) in pSTAT3 compared to the HFS group in the jejunum. Consequently, the mRNA expression of Reg3b and Reg3g were significantly upregulated in the jejunum by WG supplementation (≥42%; P ≤ 0.043). In the VAT, the HFS group had greater NF-kBp65 phosphorylation compared to C, while HFS + WG group suppressed this to the level of C (–38%; P = 0.014). In addition, VAT Il-6 and Lbp genes were downregulated in the HFS + WG group compared to HFS (P ≤ 0.0032). Macrophage-related genes, F4/80, Cd11c, and iNos, were repressed (≥−28%; P ≤ 0.048) in the VAT of WG-supplemented mice.

Conclusions

The stimulatory effects of WG on signal transducer and activator of transcription (STAT3) and AMPs in the gut may be vital to reduce the burden of antigen translocation that could initiate adipose tissue inflammation and contribute to obesity-induced IR.

Funding Sources

This study was funded by Oklahoma Agriculture Experiment Station (project # OKL02993) and by the Oklahoma State University College of Human Sciences.

The Effects of Wheat Germ Supplementation on Anthropometric, Biochemical, and Stool Measures in Overweight Adults

Objectives

This study investigated the effects of a 4-week wheat germ supplementation on anthropometric, biochemical, and stool measures in overweight adults.

Methods

Forty overweight (body mass index = 25.0–30 kg/m2) adults (18–45 years old) were recruited to participate in this randomized controlled study. After initial screening, participants were asked to consume energy balls containing either cornmeal (control) or 30 g of wheat germ (WG) daily for 4 weeks. The energy balls were isocaloric and provided an additional 225 kcal/day. Participants were asked to otherwise maintain their normal diet and physical activity. Anthropometric and metabolic parameters, as well as dietary (3-day food record), medical history, physical activity (Yale Physical Activity Survey) and stool measures (Bristol Stool Chart and the Cleveland Clinic Constipation Scoring System) were assessed at baseline and at the end of the 4-week supplementation period.

Results

Thirty-nine participants completed the 4-week supplementation (n = 20 and 19 for the WG and control group, respectively). There were no significant differences in anthropometrics, metabolic parameters (i.e., lipid panel, glucose, and HbA1c) or stool measures between the control and WG groups at baseline or at the end of supplementation. However, when comparing change from baseline, significant differences in % body fat, HbA1c, and constipation score were observed between the two groups. Individuals who received the WG supplement exhibited a greater increase in % body fat (0.68 ± 0.28% vs. 0.40 ± 0.36%, P = 0.02) and a greater decrease in HbA1c (−0.095 ± 0.05% vs. −0.039 ± 0.04%, P = 0.04). On the other hand, the control group (−1.00 ± 0.57) perceived a more significant improvement (P = 0.01) in their constipation score compared to WG (−0.85 ± 0.42).

Conclusions

Similar to our findings in animals, this study demonstrates that daily supplementation with 30 g of WG may be beneficial in glucose homeostasis as indicated by improvement in HbA1C, despite increasing % body fat. Whether the effects of WG on HbA1C will be observed at longer supplementation duration or in other populations such as obese individuals or pre-diabetics needs to be investigated in future studies.

Funding Sources

United States Department of Agriculture.