Prunes preserve cortical density and estimated strength of the tibia in a 12-month randomized controlled trial in postmenopausal women: The Prune Study.

Non-pharmacological therapies, such as whole-food interventions, are gaining interest as potential approaches to prevent and/or treat low bone mineral density (BMD) in postmenopausal women. Previously, prune consumption preserved two-dimensional BMD at the total hip. Here we demonstrate that prune consumption preserved three-dimensional BMD and estimated strength at the tibia. PURPOSE: Dietary consumption of prunes has favorable impacts on areal bone mineral density (aBMD); however, more research is necessary to understand the influence on volumetric BMD (vBMD), bone geometry, and estimated bone strength. METHODS: This investigation was a single center, parallel arm 12-month randomized controlled trial (RCT; NCT02822378) to evaluate the effects of 50 g and 100 g of prunes vs. a Control group on vBMD, bone geometry, and estimated strength of the radius and tibia via peripheral quantitative computed tomography (pQCT) in postmenopausal women. Women (age 62.1 ± 5.0yrs) were randomized into Control (n = 78), 50 g Prune (n = 79), or 100 g Prune (n = 78) groups. General linear mixed effects (LME) modeling was used to assess changes over time and percent change from baseline was compared between groups. RESULTS: The most notable effects were observed at the 14% diaphyseal tibia in the Pooled (50 g + 100 g) Prune group, in which group × time interactions were observed for cortical vBMD (p = 0.012) and estimated bone strength (SSI; p = 0.024); all of which decreased in the Control vs. no change in the Pooled Prune group from baseline to 12 months/post. CONCLUSION: Prune consumption for 12 months preserved cortical bone structure and estimated bone strength at the weight-bearing tibia in postmenopausal women.

Effects of Prune (Dried Plum) Supplementation on Cardiometabolic Health in Postmenopausal Women: An Ancillary Analysis of a 12-Month Randomized Controlled Trial, The Prune Study.

BACKGROUND: Estrogen withdrawal during menopause is associated with an unfavorable cardiometabolic profile. Prunes (dried plums) represent an emerging functional food and have been previously demonstrated to improve bone health. However, our understanding of the effects of daily prune intake on cardiometabolic risk factors in postmenopausal women is limited. OBJECTIVES: We conducted an ancillary investigation of a randomized controlled trial (RCT), The Prune Study, to evaluate the effect of 12-mo prune supplementation on cardiometabolic health markers in postmenopausal women. METHODS: The Prune Study was a single-center, parallel-design, 12-mo RCT in which postmenopausal women were allocated to no-prune control, 50 g/d prune, or 100 g/d prune groups. Blood was collected at baseline, 6 mo, and 12 mo/post to measure markers of glycemic control and blood lipids. Body composition was assessed at baseline, 6 mo, and 12 mo/post using dual-energy X-ray absorptiometry. Linear mixed-effects models were used to evaluate the effect of time, treatment, and their interaction on cardiometabolic health markers, all quantified as exploratory outcomes. RESULTS: A total of 183 postmenopausal women (mean age, 62.1 ± 4.9 y) completed the entire 12-mo RCT: control (n = 70), 50 g/d prune (n = 67), and 100 g/d prune (n = 46). Prune supplementation at 50 g/d or 100 g/d did not alter markers of glycemic control and blood lipids after 12 mo compared with the control group (all P > 0.05). Furthermore, gynoid percent fat and visceral adipose tissue (VAT) indices did not significantly differ in women consuming 50 g/d or 100 g/d prunes compared with the control group after 12 mo of intervention. However, android total mass increased by 3.19% ± 5.5% from baseline in the control group, whereas the 100 g/d prune group experienced 0.02% ± 5.6% decrease in android total mass from baseline (P < 0.01). CONCLUSIONS: Prune supplementation at 50 g/d or 100 g/d for 12 mo does not improve glycemic control and may prevent adverse changes in central adiposity in postmenopausal women. This trial was registered at clinicaltrials.gov as NCT02822378.

Prune Consumption Attenuates Proinflammatory Cytokine Secretion and Alters Monocyte Activation in Postmenopausal Women: Secondary Outcome Analysis of a 12-Mo Randomized Controlled Trial: The Prune Study.

BACKGROUND: Proinflammatory cytokines are implicated in the pathophysiology of postmenopausal bone loss. Clinical studies demonstrate that prunes prevent bone mineral density loss; however, the mechanism underlying this effect is unknown. OBJECTIVE: We investigated the effect of prune supplementation on immune, inflammatory, and oxidative stress markers. METHODS: A secondary analysis was conducted in the Prune Study, a single-center, parallel-arm, 12-mo randomized controlled trial of postmenopausal women (55-75 y old; n = 235 recruited; n = 183 completed) who were assigned to 1 of 3 groups: "no-prune" control, 50 g prune/d and 100 g prune/d groups. At baseline and after 12 mo of intervention, blood samples were collected to measure serum high-sensitivity C-reactive protein (hs-CRP), serum total antioxidant capacity (TAC), plasma 8-isoprostane, proinflammatory cytokines [interleukin (IL)-1ß, IL-6, IL-8, monocyte chemoattractant protein-1, and tumor necrosis factor (TNF)-α] concentrations in plasma and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) culture supernatants, and the percentage and activation of circulating monocytes, as secondary outcomes. RESULTS: Prune supplementation did not alter hs-CRP, TAC, 8-isoprostane, and plasma cytokine concentrations. However, percent change from baseline in circulating activated monocytes was lower in the 100 g prune/d group compared with the control group (mean ± SD, -1.8% ± 4.0% in 100 g prune/d compared with 0.1% ± 2.9% in control; P < 0.01). Furthermore, in LPS-stimulated PBMC supernatants, the percent change from baseline in TNF-α secretion was lower in the 50 g prune/d group compared with the control group (-4.4% ± 43.0% in 50 g prune/d compared with 24.3% ± 70.7% in control; P < 0.01), and the percent change from baseline in IL-1ß, IL-6, and IL-8 secretion was lower in the 100 g prune/d group compared with the control group (-8.9% ± 61.6%, -4.3% ± 75.3%, -14.3% ± 60.8% in 100 g prune/d compared with 46.9% ± 107.4%, 16.9% ± 70.6%, 39.8% ± 90.8% in control for IL-1ß, IL-6, and IL-8, respectively; all P < 0.05). CONCLUSIONS: Dietary supplementation with 50-100 g prunes for 12 mo reduced proinflammatory cytokine secretion from PBMCs and suppressed the circulating levels of activated monocytes in postmenopausal women. This trial was registered at clinicaltrials.gov as NCT02822378.

Spices in a High-Saturated-Fat, High-Carbohydrate Meal Reduce Postprandial Proinflammatory Cytokine Secretion in Men with Overweight or Obesity: A 3-Period, Crossover, Randomized Controlled Trial.

BACKGROUND: Postprandial inflammation that occurs concurrently with hyperglycemia and hyperlipidemia after ingestion of a high-saturated-fat, high-carbohydrate meal (HFCM) is a risk factor for cardiovascular disease (CVD). Numerous preclinical and clinical studies demonstrate anti-inflammatory effects of individual spices. However, the effect of consumption of a spice blend on inflammatory mediators has not been examined in a randomized controlled trial. OBJECTIVES: The objective of this study was to investigate the postprandial effect of a blend of spices in a HFCM on inflammatory cytokine responses. METHODS: Nonsmoking men (40-65 y old) with overweight/obesity (25 ≤ BMI ≤ 35 kg/m2), elevated waist circumference (≥ 94 cm), and ≥ 1 CVD risk factor were recruited for a 3-period crossover study ( n = 12). In random order, participants consumed the following: a HFCM (∼1000 kcal, 33% kcal from saturated fat and 36% kcal from carbohydrate), a HFCM containing 2 g spice blend, or an HFCM containing 6 g spice blend. The spice blend consisted of basil, bay leaf, black pepper, cinnamon, coriander, cumin, ginger, oregano, parsley, red pepper, rosemary, thyme, and turmeric. Blood was collected before, and hourly for 4 h after the HFCM. Peripheral blood mononuclear cells (PBMCs) were isolated, and the percentage of CD14 +/Human Leukocyte Antigen-DR isotype + (HLA-DR +) monocytes and proinflammatory cytokine concentrations in plasma and LPS-stimulated PBMCs were quantified as secondary outcomes. RESULTS: There was a significant spice-by-time interaction on IL-1ß (P < 0.001), IL-8 (P = 0.020), and TNF-α (P = 0.009) secretion from LPS-stimulated PBMCs. IL-1ß secretion from LPS-stimulated PBMCs was significantly reduced (1314%) at 240 min after HFCM consumption containing 6 g, but not 2 g, of spice blend compared with 0 g spice blend. CONCLUSIONS: A HFCM containing 6 g spice blend attenuated HFCM-induced postprandial IL-1ß secretion in men with overweight/obesity.This trial was registered at clinicaltrials.gov as NCT03064958.

Linking the Gut Microbiota to Bone Health in Anorexia Nervosa.

PURPOSE OF REVIEW: The purpose of this review is to examine the anorexia nervosa-microbiota-bone relationship, offering a compilation of the relevant human and animal studies that may contribute to a more comprehensive understanding of potential mechanisms involved. RECENT FINDINGS: Recent studies have implicated fermentation by-products of the gut microbiota in bone metabolism. Compromised bone health often accompanies anorexia nervosa due to energy deficiency and hypoestrogenism. The gut microbiome has been implicated as a link between these conditions and impaired bone growth phenotypes. Current research supports decrements in Firmicutes and short-chain fatty acids with increases in Methanobrevibacter smithii and Proteobacteria in anorexia nervosa. A potential mechanism for microbiome-regulated bone growth is through modulation of insulin-like growth factor-1. Future research should aim to examine short-chain fatty acids, probiotics, and prebiotics as alternative therapies to treat low bone density in anorexia nervosa.

Lipid Emulsion Added to a Liquid High-Carbohydrate Diet and Voluntary Running Exercise Reduce Lipogenesis and Ameliorate Early-Stage Hepatic Steatosis in Mice.

Background: The use of parenteral nutrition formulas is often associated with the development of hepatic steatosis. We have shown previously that the addition of a lipid emulsion (LE) rich in n-6 (ω-6) fatty acids (FAs) ameliorated triglyceride (TG) accumulation in the livers of nonobese mice fed a high-carbohydrate diet (HCD) for 5 wk. However, it remains unclear how rapidly this condition develops and whether it can be prevented by LE with or without a running wheel for voluntary exercise (Exe).Objective: We investigated in an 8-d study whether mice develop steatosis and whether the administration of LE with or without Exe reduces the concentration of total FAs and prevents an increase in the expression of genes in the liver associated with lipogenesis.Methods: Male C57BL/6 mice aged 5 wk were randomized into 5 groups: standard feed pellet (SFP); a liquid HCD (77% of total energy from carbohydrates and 0.5% from fat); HCD + Exe; HCD + 13.5% LE (67% carbohydrates and 13.5% fat); or HCD + 13.5% LE + Exe. Hepatic TG concentration, lipogenic genes, and total FAs were measured on day 8.Results: Oil Red O staining and TG quantification showed hepatic TG accumulation on day 8; the addition of 13.5% LE either with or without Exe suppressed the TG accumulation compared with HCD (P < 0.005). With the use of quantitative reverse transcriptase-polymerase chain reaction analysis, the expression concentrations of lipogenic genes [ATP-citrate lyase, acetyl coenzyme A carboxylase 1, FA synthase (Fasn), and stearoyl coenzyme A desaturase 1 (Scd1)] in the HCD + 13.5% LE group were 26-60% of HCD (P < 0.01) and 11-38% of HCD in the HCD + 13.5% LE + Exe group (P < 0.001), with interactions for Fasn and Scd1 (P < 0.05). With the use of gas chromatography-mass spectrometry analysis, the HCD + 13.5% LE group had lower monounsaturated fatty acids (38.7% of HCD) but higher polyunsaturated fatty acids (164% of HCD) (P < 0.001).Conclusions: In short-term studies designed to resemble the early dynamic stage of the development of hepatic steatosis, the addition of 13.5% LE to a liquid HCD reduced hepatic lipogenesis. Exe exerted an independent protective effect and interacted with LE to further reduce the expression of Scd1.

Consumption of Bifidobacterium animalis subsp. lactis BB-12 in yogurt reduced expression of TLR-2 on peripheral blood-derived monocytes and pro-inflammatory cytokine secretion in young adults.

PURPOSE: Probiotic bacteria modulate immune parameters and inflammatory outcomes. Emerging evidence demonstrates that the matrix used to deliver probiotics may influence the efficacy of probiotic interventions in vivo. The aims of the current study were to evaluate (1) the effect of one species, Bifidobacterium animalis subsp. lactis BB-12 at a dose of log10 ± 0.5 CFUs/day on immune responses in a randomized, partially blinded, 4-period crossover, free-living study, and (2) whether the immune response to BB-12 differed depending on the delivery matrix. METHODS: Healthy adults (n = 30) aged 18-40 years were recruited and received four treatments in a random order: (A) yogurt smoothie alone; smoothie with BB-12 added (B) before or (C) after yogurt fermentation, or (D) BB-12 given in capsule form. At baseline and after each 4-week treatment, peripheral blood mononuclear cells (PBMCs) were isolated, and functional and phenotypic marker expression was assessed. RESULTS: BB-12 interacted with peripheral myeloid cells via Toll-like receptor 2 (TLR-2). The percentage of CD14+HLA-DR+ cells in peripheral blood was increased in male participants by all yogurt-containing treatments compared to baseline (p = 0.0356). Participants who consumed yogurt smoothie with BB-12 added post-fermentation had significantly lower expression of TLR-2 on CD14+HLA-DR+ cells (p = 0.0186) and reduction in TNF-α secretion from BB-12- (p = 0.0490) or LPS-stimulated (p = 0.0387) PBMCs compared to baseline. CONCLUSIONS: These findings not only demonstrate a potential anti-inflammatory effect of BB-12 in healthy adults, but also indicate that the delivery matrix influences the immunomodulatory properties of BB-12.

Effects of Bifidobacterium animalis subsp. lactis BB-12® on the lipid/lipoprotein profile and short chain fatty acids in healthy young adults: a randomized controlled trial.

BACKGROUND: Some probiotics have hypocholesterolemic effects in animal studies, which are mediated, in part, by increases in fecal short chain fatty acids (SCFAs). Clinical trials of probiotics on lipids/lipoproteins are inconsistent. OBJECTIVE: We examined the effects of Bifidobacterium animalis subsp. lactis BB-12® (BB-12®) (3.16 × 109 CFUs/day) on lipids and lipoproteins and fecal excretion of SCFAs in healthy adults. METHODS: In a randomized, partially blinded, 4-period, crossover study, 30 adults (11 men, 19 women) aged 18-40 years were randomly assigned to: 1) yogurt smoothie with no BB-12® (YS), 2) yogurt smoothie with BB-12® added pre-fermentation (PRE), 3) yogurt smoothie with BB-12® added post-fermentation (POST), 4) BB-12® containing capsule (CAP). We measured serum lipids/lipoproteins, glucose, insulin, C-reactive protein (CRP), and fecal SCFAs at baseline and after each treatment period. RESULTS: Total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglycerides (TGs) did not differ after the PRE, POST, and CAP periods versus the YS or between treatments. Compared to baseline, fecal acetate was significantly increased after the YS (Δ = 211.89 ± 75.87 µg/g, P = 0.007) and PRE (Δ = 204.98 ± 75.70 µg/g, P = 0.009) periods. The percent increase in fecal acetate was significantly greater after the YS versus the POST period (52.2 ± 13.2% vs. 24.5 ± 13.2%, P = 0.023). Fecal total SCFAs, propionate and butyrate did not differ between treatment periods. Fecal total SCFAs were negatively associated with TC (r = -0.22, P = 0.01), LDL-C (r = -0.24, P = 0.004), age (r = -0.33, P < 0.001), and waist circumference (r = -0.25, P = 0.003). CONCLUSIONS: BB-12® supplementation did not improve lipids, lipoproteins and total and individual fecal SCFAs. Fecal SCFAs were negatively associated with TC, LDL-C, age, and waist circumference. TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov as NCT01399996 .

Dietary Iron and Colorectal Cancer Risk: A Review of Human Population Studies.

Iron is an essential micronutrient that is involved in many redox processes and serves as an integral component in various physiological functions. However, excess iron can cause tissue damage through its pro-oxidative effects, potentiating the development of many diseases such as cancer through the generation of reactive oxidative species. The two major forms of iron in the diet are heme and nonheme iron, both of which are found in several different foods. In addition to natural food sources, intake of nonheme iron may also come from fortified foods or in supplement form. This review summarizes the results of human population studies that have examined the role of dietary iron (heme and nonheme), heme iron alone, and iron from supplements in colorectal carcinogenesis.

Fish Oil Enhances T Cell Function and Tumor Infiltration and Is Correlated With a Cancer Prevention Effect in HER-2/neu But Not PyMT Transgenic Mice.

Few studies have explored the effects of omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation on immune modulation in murine models of mammary carcinogenesis. HER-2/neu and PyMT mice were randomized to 2 dietary interventions: AIN-93G-based diet with 1) 11% of diet (per gram weight) as corn oil (CO) or 2) 10% of diet as menhaden fish oil plus 1% of diet as corn oil (FO). FO significantly reduced the incidence and multiplicity of tumors (P < 0.001) in HER-2/neu, but not PyMT mice. FO-fed mice had significantly larger splenocyte counts than CO-fed mice in both the HER-2/neu and PyMT models; and in both models this was comprised of an increase in most cell types, including Gr-1(+)/CD11b(+) cells. T cells from FO-fed HER-2/neu mice produced significantly more interleukin-2 (P = 0.004) and interferon-γ (P = 0.012) in response to in vitro stimulation with anti-CD3 (0.5 µg/ml). Lastly, FO-fed HER-2/neu mice had significantly more tumor immune infiltrates than CO-fed mice, including NK1.1(+), F4/80(+), and Gr-1(+)/CD11b(+) cells (P ≤ 0.05). Greater Th1 cytokine production and significantly more tumor immune infiltrates in FO-fed Her2/neu mice may account for the cancer prevention effect of fish oil in this model.

Dietary methionine restriction inhibits prostatic intraepithelial neoplasia in TRAMP mice.

BACKGROUND: Prostate cancer (PCa) is a major aging-related disease for which little progress has been made in developing preventive strategies. Over the past several years, methionine restriction (MR), the feeding of a diet low in methionine (Met), has been identified as an intervention which significantly extends lifespan and reduces the onset of chronic diseases, including cancer, in laboratory animals. We, therefore, hypothesized that MR may be an effective strategy for inhibiting PCa. METHODS: Control (0.86% Met) or MR (0.12% Met) diets were fed to 5-week old TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) mice, a well-characterized model for PCa. The mice were sacrificed at 16 weeks of age and prostate and other tissues were harvested for histological and biochemical analyses. RESULTS: As previously reported, MR was associated with a decrease in body weight which was not associated with lowered food intake. MR led to significant reductions in the development of Prostatic Intraepithelial Neoplasia (PIN) lesions, specifically in the anterior and dorsal lobes of the prostate where the incidence of high-grade PIN was reduced by ∼50% (P < 0.02). The reduction in PIN severity was associated with 46-64% reductions in cell proliferation rates (P < 0.02) and plasma IGF-1 levels (P < 0.0001), which might, in part, explain the effects on carcinogenesis. Additionally, no adverse consequences of MR on immune function were observed in the TRAMP mice. CONCLUSIONS: Overall, these findings indicate that MR is associated with a reduction in prostate cancer development in the TRAMP model and supports the continued development of MR as a potential PCa prevention strategy.

Effect of Probiotic Supplementation on Intestinal Permeability in Overweight and Obesity: A Systematic Review of Randomized Controlled Trials and Animal Studies.

Overweight and obesity are associated with increased intestinal permeability, characterized by loss of gut epithelial integrity, resulting in unregulated passage of lipopolysaccharide (LPS) and other inflammatory triggers into circulation, i.e., metabolic endotoxemia. In obesity, shifts in the gut microbiome negatively impact intestinal permeability. Probiotics are an intervention that can target the gut microbiome by introducing beneficial microbial species, potentially restoring gut barrier integrity. Currently, the role of probiotic supplementation in ameliorating obesity- and overweight-associated increases in gut permeability has not been reviewed. This systematic review aimed to summarize findings from both animal and clinical studies that evaluated the effect of probiotic supplementation on obesity-induced impairment in intestinal permeability (International Prospective Register of Systematic Reviews, CRD42022363538). A literature search was conducted using PubMed (Medline), Web of Science, and CAB Direct from origin until August 2023 using keywords of intestinal permeability, overweight or obesity, and probiotic supplementation. Of 920 records, 26 eligible records were included, comprising 12 animal and 14 clinical studies. Clinical trials ranged from 3 to 26 wk and were mostly parallel-arm (n = 13) or crossover (n = 1) design. In both animal and clinical studies, plasma/serum LPS was the most common measure of intestinal permeability. Eleven of 12 animal studies reported a positive effect of probiotic supplementation in reducing intestinal permeability. However, results from clinical trials were inconsistent, with half reporting reductions in serum LPS and half reporting no differences after probiotic supplementation. Bifidobacterium, Lactobacillus, and Akkermansia emerged as the most common genera in probiotic formulations among the animal and clinical studies that yielded positive results, suggesting that specific bacteria may be more effective at reducing intestinal permeability and improving gut barrier function. However, better standardization of strain use, dosage, duration, and the delivery matrix is needed to fully understand the probiotic impact on intestinal permeability in individuals with overweight and obesity.

The Effects of Bifidobacterium Probiotic Supplementation on Blood Glucose: A Systematic Review and Meta-Analysis of Animal Models and Clinical Evidence.

Probiotic supplementation is a potential therapeutic for metabolic diseases, including obesity, metabolic syndrome (MetS), and type 2 diabetes (T2D), but most studies deliver multiple species of bacteria in addition to prebiotics or oral pharmaceuticals. This may contribute to conflicting evidence in existing meta-analyses of probiotics in these populations and warrants a systematic review of the literature to assess the contribution of a single probiotic genus to better understand the contribution of individual probiotics to modulate blood glucose. We conducted a systematic review and meta-analysis of animal studies and human randomized controlled trials (RCTs) to assess the effects of Bifidobacterium (BF) probiotic supplementation on markers of glycemia. In a meta-analysis of 6 RCTs, BF supplementation had no effect on fasting blood glucose {FBG; mean difference [MD] = -1.99 mg/dL [95% confidence interval (CI): -4.84, 0.86], P = 0.13}, and there were no subgroup differences between subjects with elevated FBG concentrations and normoglycemia. However, BF supplementation reduced FBG concentrations in a meta-analysis comprised of studies utilizing animal models of obesity, MetS, or T2D [n = 16; MD = -36.11 mg/dL (CI: -49.04, -23.18), P < 0.0001]. Translational gaps from animal to human trials include paucity of research in female animals, BF supplementation in subjects that were normoglycemic, and lack of methodologic reporting regarding probiotic viability and stability. More research is necessary to assess the effects of BF supplementation in human subjects with elevated FBG concentrations. Overall, there was consistent evidence of the efficacy of BF probiotics to reduce elevated FBG concentrations in animal models but not clinical trials, suggesting that BF alone may have minimal effects on glycemic control, may be more effective when combined with multiple probiotic species, or may be more effective in conditions of hyperglycemia rather than elevated FBG concentrations.

Gut microbes differ in postmenopausal women responding to prunes to maintain hip bone mineral density.

Foods high in phenolics such as prunes have been shown to exert protective effects on bone mineral density (BMD), but only certain individuals experience these benefits. This post-hoc analysis of a 12-month randomized controlled trial aimed to identify the relationship among the gut microbiome, immune responses, and bone protective effects of prunes on postmenopausal women. Subjects who consumed 50-100 g prunes daily were divided into responders (n = 20) and non-responders (n = 32) based on percent change in total hip bone mineral density (BMD, ≥1% or ≤-1% change, respectively). DXA scans were used to determine body composition and BMD. Immune markers were measured using immunoassays and flow cytometry. Targeted phenolic metabolites were analyzed using ultra performance liquid chromatography-tandem mass spectrometry. The fecal microbiota was characterized through 16S rRNA gene PCR amplicon sequencing. After 12 months of prune consumption, anti-inflammatory markers showed responders had significantly lower levels of IL-1ß and TNF-α. QIIME2 sequence analysis showed that microbiomes of responders and non-responders differed in alpha (Shannon and Faith PD, Kruskal-Wallis p < 0.05) and beta diversity (unweighted Unifrac, PERMANOVA p < 0.04) metrics both before and after prune treatment. Furthermore, responders had a higher abundance of bacterial families Oscillospiraceae and Lachnospiraceae (ANCOM-BC p < 0.05). These findings provide evidence that postmenopausal women with initial low BMD can benefit from prunes if they host certain gut microbes. These insights can guide precision nutrition strategies to improve BMD tailored to diet and microbiome composition.

Changes in the type 2 diabetes gut mycobiome associate with metformin treatment across populations.

The human gut teems with a diverse ecosystem of microbes, yet non-bacterial portions of that community are overlooked in studies of metabolic diseases firmly linked to gut bacteria. Type 2 diabetes mellitus (T2D) is associated with compositional shifts in the gut bacterial microbiome and the mycobiome, the fungal portion of the microbiome. However, whether T2D and/or metformin treatment underpins fungal community changes is unresolved. To differentiate these effects, we curated a gut mycobiome cohort spanning 1,000 human samples across five countries and validated our findings in a murine experimental model. We use Bayesian multinomial logistic normal models to show that T2D and metformin both associate with shifts in the relative abundance of distinct gut fungi. T2D is associated with shifts in the Saccharomycetes and Sordariomycetes fungal classes, while the genera Fusarium and Tetrapisipora most consistently associate with metformin treatment. We confirmed the impact of metformin on individual gut fungi by administering metformin to healthy mice. Thus, metformin and T2D account for subtle, but significant and distinct variation in the gut mycobiome across human populations. This work highlights for the first time that metformin can confound associations of gut fungi with T2D and warrants the need to consider pharmaceutical interventions in investigations of linkages between metabolic diseases and gut microbial inhabitants. IMPORTANCE: This is the largest to-date multi-country cohort characterizing the human gut mycobiome, and the first to investigate potential perturbations in gut fungi from oral pharmaceutical treatment. We demonstrate the reproducible effects of metformin treatment on the human and murine gut mycobiome and highlight a need to consider metformin as a confounding factor in investigations between type 2 diabetes mellitus and the gut microbial ecosystem.

Immunometabolic role of long-chain omega-3 fatty acids in obesity-induced inflammation.

Inflammation links obesity with the development of insulin resistance. Macrophages and phagocytic immune cells communicate with metabolic tissues to direct an inflammatory response caused by overnutrition and expanding adipose tissue. Marine-derived omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), modulate inflammatory signalling events, providing various anti-inflammatory and cardioprotective benefits. Moreover, EPA and DHA may improve insulin sensitivity by generating proresolving lipid mediators and promoting alternatively activated macrophages. This review will assess the role of EPA and DHA in ameliorating obesity-induced inflammation, evaluating clinical evidence and mechanisms of action. The pathophysiology of insulin resistance resulting from obesity-induced inflammation will be discussed, highlighting the relationship between metabolism and immunity, and in particular, how EPA and DHA work with both systems to modulate immunometabolic complications and chronic disease.

Vitamin D regulates the gut microbiome and protects mice from dextran sodium sulfate-induced colitis.

The active form of vitamin D [1,25-dihydroxycholecalciferol, 1,25(OH)2D3] and the vitamin D receptor (VDR) regulate susceptibility to experimental colitis. The effect of the bacterial microflora on the susceptibility of C57BL/6 mice to dextran sodium sulfate-induced colitis was determined. Mice that cannot produce 1,25(OH)2D3 [Cyp27b1 (Cyp) knockout (KO)], VDR KO as well as their wild-type littermates were used. Cyp KO and VDR KO mice had more bacteria from the Bacteroidetes and Proteobacteria phyla and fewer bacteria from the Firmicutes and Deferribacteres phyla in the feces compared with wild-type. In particular, there were more beneficial bacteria, including the Lactobacillaceae and Lachnospiraceae families, in feces from Cyp KO and VDR KO mice than in feces from wild-type. Helicobacteraceae family member numbers were elevated in Cyp KO compared with wild-type mice. Depletion of the gut bacterial flora using antibiotics protected mice from colitis. 1,25(OH)2D3 treatment (1.25 µg/100 g diet) of Cyp KO mice decreased colitis severity and reduced the numbers of Helicobacteraceae in the feces compared with the numbers in the feces of untreated Cyp KO mice. The mechanisms by which the dysbiosis occurs in VDR KO and Cyp KO mice included lower expression of E-cadherin on gut epithelial and immune cells and fewer tolerogenic dendritic cells that resulted in more gut inflammation in VDR and Cyp KO mice compared with wild-type mice. Increased host inflammation has been shown to provide pathogens with substrates to out-compete more beneficial bacterial species. Our data demonstrate that vitamin D regulates the gut microbiome and that 1,25(OH)2D3 or VDR deficiency results in dysbiosis, leading to greater susceptibility to injury in the gut.

Associations Between Inflammatory Mediators and Bone Outcomes in Postmenopausal Women: A Cross-Sectional Analysis of Baseline Data from the Prune Study.

Purpose: Hypoestrogenism triggers increased production of inflammatory mediators, which contribute to bone loss during postmenopausal osteoporosis. This study aimed to investigate the association between circulating inflammatory markers and bone outcomes in postmenopausal women. Materials and methods: We conducted a cross-sectional, secondary analysis of baseline data from participants who completed a 12-month randomized controlled trial, The Prune Study (NCT02822378), which included healthy postmenopausal women (n=183, 55-75 years old) with bone mineral density (BMD) T-score between 0.0 and -3.0 at any site. BMD was measured using dual-energy X-ray absorptiometry, and bone geometry and strength were measured using peripheral quantitative computed tomography. Blood was collected at baseline to measure (1) serum biomarkers of bone turnover, including procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide and (2) inflammatory markers, including serum high-sensitivity C-reactive protein (hs-CRP) and plasma pro-inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-8, and monocyte chemoattractant protein (MCP)-1, using enzyme-linked immunosorbent assay. The associations between bone and inflammatory outcomes at baseline were analyzed using correlation and regression analyses. Results: Serum hs-CRP negatively correlated with P1NP (r=-0.197, p=0.042). Plasma IL-1ß, IL-6, IL-8, and TNF-α negatively correlated with trabecular bone score at the lumbar spine (all p<0.05). In normal-weight women, plasma IL-1ß, IL-6, and IL-8 negatively correlated (p<0.05) with trabecular and cortical bone area, content, and density at various sites in the tibia and radius. Serum hs-CRP positively predicted lumbar spine BMD (ß=0.078, p=0.028). Plasma IL-6 negatively predicted BMD at the total body (ß=-0.131, p=0.027) and lumbar spine (ß=-0.151, p=0.036), whereas plasma TNF-α negatively predicted total hip BMD (ß=-0.114, p=0.028). Conclusion: At baseline, inflammatory markers were inversely associated with various estimates of bone density, geometry, and strength in postmenopausal women. These findings suggest that inflammatory markers may be an important mediator for postmenopausal bone loss.

Associations Between Leisure-Time Physical Activity Level and Peripheral Immune Cell Populations in the US General Population, Analysis of the National Health and Nutrition Examination Survey Data, 1999-2018.

BACKGROUND: Chronic levels of inflammation are associated with higher risk of many chronic diseases. Physical activity (PA) lowers the risk of cancer, cardiovascular disease (CVD), diabetes and others. One mechanism for PA-induced protection may be through the immune system. We investigated the association between leisure-time PA and peripheral immune cell populations in a large nationally representative sample of the US general population. METHODS: A total of 17,093 participants [mean (SE) age of 41.6 (0.3) years] of the National Health and Nutrition Examination Survey 1999-2018 were included. Self-reported leisure-time PA was converted to metabolic equivalent of task hours per week (MET-hrs/wk). White blood cell (WBC) count, WBC ratios, and platelet count were derived. Multivariable linear regression analyses were used to estimate associations between leisure-time PA level and peripheral immune cell populations. Multivariable logistic regression analyses were used to estimate associations between leisure-time PA and metrics of WBC count and neutrophil-to-lymphocyte ratio (NLR) which may predict mortality. RESULTS: A higher leisure-time PA level was associated with a lower WBC count (> 14.0 vs. < 1.2 MET-hrs/wk adjusted mean (95% confidence interval [CI]): 7.12 (6.86, 7.38) vs. 7.38 (7.12, 7.64) 1000 cells/µL, Ptrend < 0.001) and a lower NLR (> 14.0 vs. < 1.2 MET-hrs/wk adjusted mean (95% CI) 2.04 (1.90, 2.18) vs. 2.13 (1.99, 2.28), Ptrend = 0.007). Leisure-time PA level was not associated with lymphocyte-to-monocyte ratio (LMR; Ptrend = 0.25) or platelet-to-lymphocyte ratio (PLR; Ptrend = 0.69). Compared to the lowest leisure-time PA level (< 1.2 MET-hrs/wk), the highest leisure-time PA level (≥ 14.0 MET-hrs/wk) was associated with a lower probability of a high WBC count (> 8.1 × 109 cells/L; odds ratio [OR] = 0.76, 95% CI = 0.66-0.88) and high NLR (> 2.68; OR = 0.84, 95% CI = 0.72-0.99), which may predict CVD and all-cause mortality. The highest leisure-time PA level also linked to a lower probability of a high WBC count (≥ 8.3 × 109 cells/L; OR = 0.76, 95% CI = 0.66-0.88), which may predict cancer mortality. CONCLUSIONS: We observed an inverse association between leisure-time PA level, WBC count, and NLR, particularly for neutrophil levels. These results suggest that participants at higher levels of leisure-time PA may have lower levels of inflammation, which may be important for future chronic disease outcomes.

Changes in the Type 2 diabetes gut mycobiome associate with metformin treatment across populations.

The human gut teems with a diverse ecosystem of microbes, yet non-bacterial portions of that community are overlooked in studies of metabolic diseases firmly linked to gut bacteria. Type 2 diabetes mellitus (T2D) associates with compositional shifts in the gut bacterial microbiome and fungal mycobiome, but whether T2D and/or pharmaceutical treatments underpin the community change is unresolved. To differentiate these effects, we curated a gut mycobiome cohort to-date spanning 1,000 human samples across 5 countries and a murine experimental model. We use Bayesian multinomial logistic normal models to show that metformin and T2D both associate with shifts in the relative abundance of distinct gut fungi. T2D associates with shifts in the Saccharomycetes and Sordariomycetes fungal classes, while the genera Fusarium and Tetrapisipora most consistently associate with metformin treatment. We confirmed the impact of metformin on individual gut fungi by administering metformin to healthy mice. Thus, metformin and T2D account for subtle, but significant and distinct variation in the gut mycobiome across human populations. This work highlights for the first time that oral pharmaceuticals can confound associations of gut fungi with T2D and warrants the need to consider pharmaceutical interventions in investigations of linkages between metabolic diseases and gut microbial inhabitants.