Barry Goldin’s research while affiliated with Tufts University and other places

Background: Emerging evidence suggests novel roles for bacterially derived vitamin K forms known as menaquinones in health and disease, which may be attributable in part to anti-inflammatory effects. However, the relevance of menaquinones produced by gut bacteria to vitamin K requirements and inflammation is undetermined. Objective: This study aimed to quantify fecal menaquinone concentrations and identify associations between fecal menaquinone concentrations and serum vitamin K concentrations, gut microbiota composition, and inflammation. Design: Fecal and serum menaquinone concentrations, fecal microbiota composition, and plasma and fecal cytokine concentrations were measured in 80 men and postmenopausal women (48 men, 32 women, age 40–65 y) enrolled in a randomized, parallel-arm, provided-food trial. After consuming a run-in diet for 2 wk, participants were randomly assigned to consume a whole grain–rich (WG) or a refined grain–based (RG) diet for 6 wk. Outcomes were measured at weeks 2 and 8. Results: The median total daily excretion of menaquinones in feces was 850 nmol/d but was highly variable (range: 64–5358 nmol/d). The total median (IQR) fecal concentrations of menaquinones decreased in the WG diet compared with the RG diet [−6.8 nmol/g (13.0 nmol/g) dry weight for WG compared with 1.8 nmol/g (12.3 nmol/g) dry weight for RG; P < 0.01)]. However, interindividual variability in fecal menaquinone concentrations partitioned individuals into 2 distinct groups based on interindividual differences in concentrations of different menaquinone forms rather than the diet group or the time point. The relative abundances of several gut bacteria taxa, Bacteroides and Prevotella in particular, differed between these groups, and 42% of identified genera were associated with ≥1 menaquinone form. Menaquinones were not detected in serum, and neither fecal concentrations of individual menaquinones nor the menaquinone group was associated with any marker of inflammation. Conclusion: Menaquinone concentrations in the human gut appear highly variable and are associated with gut microbiota composition. However, the health implications remain unclear. This trial was registered at clinicaltrials.gov as NCT01902394.

Aim: To develop a novel validated method for the isolation of Bifidobacterium animalis subsp lactis BB-12 (BB-12) from fecal specimens and apply it to studies of BB-12 and Lactobacillus rhamnosus GG (LGG) recovered from the healthy human gastrointestinal (GI) tract. Methods and results: A novel method for isolating and enumerating BB-12 was developed based on its morphologic features of growth on tetracycline-containing agar. The method identified BB-12 correctly from spiked stool close to100% of the time as validated by PCR confirmation of identity, and resulted in 97-104% recovery of BB-12. The method was then applied in a study of the recovery of BB-12 and LGG from the GI tract of healthy humans consuming ProNutrients(®) Probiotic powder sachet containing BB-12 and LGG. Viable BB-12 and LGG were recovered from stool after 21 d of probiotic ingestion compared to baseline. In contrast, no organisms were recovered 21 d after baseline in the non-supplemented control group. Conclusions: We demonstrated recovery of viable BB-12, using a validated novel method specific for the isolation of BB-12, and LGG from the GI tract of healthy humans who consumed the probiotic supplement. Significance and impact: This method will enable more detailed and specific studies of BB-12 in probiotic supplements, including when in combination with LGG. This article is protected by copyright. All rights reserved.

Background: Observational studies suggest an inverse association between whole-grain (WG) consumption and inflammation. However, evidence from interventional studies is limited, and few studies have included measurements of cell-mediated immunity.Objective:We assessed the effects of diets rich in WGs compared with refined grains (RGs) on immune and inflammatory responses, gut microbiota, and microbial products in healthy adults while maintaining subject body weights.Design:After a 2-wk provided-food run-in period of consuming a Western-style diet, 49 men and 32 postmenopausal women [age range: 40-65 y, body mass index (in kg/m2) <35] were assigned to consume 1 of 2 provided-food weight-maintenance diets for 6 wk.Results:Compared with the RG group, the WG group had increased plasma total alkyresorcinols (a measure of WG intake) (P< 0.0001), stool weight (P< 0.0001), stool frequency (P= 0.02), and short-chain fatty acid (SCFA) producerLachnospira[false-discovery rate (FDR)-correctedP= 0.25] but decreased pro-inflammatoryEnterobacteriaceae(FDR-correctedP= 0.25). Changes in stool acetate (P= 0.02) and total SCFAs (P= 0.05) were higher in the WG group than in the RG group. A positive association was shown betweenLachnospiraand acetate (FDR-correctedP= 0.002) or butyrate (FDR-correctedP= 0.005). We also showed that there was a higher percentage of terminal effector memory T cells (P= 0.03) and LPS-stimulated ex vivo production of tumor necrosis factor-α (P= 0.04) in the WG group than in the RG group, which were positively associated with plasma alkylresorcinol concentrations.Conclusion:The short-term consumption of WGs in a weight-maintenance diet increases stool weight and frequency and has modest positive effects on gut microbiota, SCFAs, effector memory T cells, and the acute innate immune response and no effect on other markers of cell-mediated immunity or systemic and gut inflammation. This trial was registered at clinicaltrials.gov as NCT01902394.

Background: The effect of whole grains on the regulation of energy balance remains controversial. Objective: We aimed to determine the effects of substituting whole grains for refined grains, independent of body weight changes, on energy-metabolism metrics and glycemic control. Design: The study was a randomized, controlled, parallel-arm controlled-feeding trial that was conducted in 81 men and postmenopausal women [49 men and 32 women; age range: 40–65 y; body mass index (in kg/m2): <35.0]. After a 2-wk run-in period, participants were randomly assigned to consume 1 of 2 weight-maintenance diets for 6 wk. Diets differed in whole-grain and fiber contents [mean ± SDs: whole grain–rich diet: 207 ± 39 g whole grains plus 40 ± 5 g dietary fiber/d; refined grain–based diet: 0 g whole grains plus 21 ± 3 g dietary fiber/d] but were otherwise similar. Energy metabolism and body-composition metrics, appetite, markers of glycemic control, and gut microbiota were measured at 2 and 8 wk. Results: By design, body weight was maintained in both groups. Plasma alkylresorcinols, which are biomarkers of whole-grain intake, increased in the whole grain–rich diet group (WG) but not in the refined grain–based diet group (RG) (P-diet-by-time interaction < 0.0001). Beta ± SE changes (ΔWG compared with ΔRG) in the resting metabolic rate (RMR) (43 ± 25 kcal/d; P = 0.04), stool weight (76 ± 12 g/d; P < 0.0001), and stool energy content (57 ± 17 kcal/d; P = 0.003), but not in stool energy density, were higher in the WG. When combined, the favorable energetic effects in the WG translated into a 92-kcal/d (95% CI: 28, 156-kcal/d) higher net daily energy loss compared with that of the RG (P = 0.005). Prospective consumption (P = 0.07) and glycemia after an oral-glucose-tolerance test (P = 0.10) trended toward being lower in the WG than in the RG. When nonadherent participants were excluded, between-group differences in stool energy content and glucose tolerance increased, and between-group differences in the RMR and prospective consumption were not statistically significant. Conclusion: These findings suggest positive effects of whole grains on the RMR and stool energy excretion that favorably influence energy balance and may help explain epidemiologic associations between whole-grain consumption and reduced body weight and adiposity. This trial was registered at clinicaltrials.gov as NCT01902394.

Observational studies suggest an association between diets rich in whole grains (WG) and a decrease in inflammatory markers. Yet, this is not clearly supported by the conflicting or limited number of interventional studies, few of which have included markers of cell‐mediated immunity, which are important functional aspects of the immune system. Furthermore, WG consumption is often accompanied by weight loss, which may impact immune and inflammatory markers independent of a WG effect. This study was designed to maintain weight while investigating the effect of a WG rich diet versus refined grains (RG) on immune and inflammatory responses, gut microbiota, and microbial products. Following a 2‐wk provided‐food run‐in period, 49 men and 32 post‐menopausal women (40–65 yr, BMI < 35.0 kg/m ² ) were randomly assigned to one of two provided‐food weight‐maintenance diets for 6 weeks. The diets differed in WG and fiber contents (WG [n=41]: 207±39 g WG/d, 40±5 g fiber/d; or RG [n=40]: 0 g WG/d, 21±3 g fiber/d), but were similar in energy and meal structure. Relative abundances of gut bacteria were measured using DNA extracted from stool samples collected at PRE and POST, and by high‐throughput sequencing of amplicons of the V4 region of the 16S rRNA gene. To assess the impact of WG on immune and inflammatory markers we measured a panel of inflammatory markers, phenotypic, and functional aspects of the immune system. Compliance was assessed by measuring biomarkers of WG intake, plasma alkylresorcinols (ARs), at the end of the run‐in (PRE) and end of week‐6 (POST) periods. We observed a significant increase in PRE to POST plasma ARs concentration in the WG group, and the PRE to POST change in plasma ARs was significantly higher in the WG compared to the RG (p< 0.001). Consumption of WG versus RG significantly increased 72h stool weight (p<0.001) and frequency (p=0.002). We noted a modest effect on gut microbiota and short chain fatty acid (SCFA): WG consumption resulted in a trend towards a decrease in Firmicutes and increase in Bacteroidetes and Fusobacteria POST intervention (FDR<0.30), and a significant increase in PRE to POST change in the SCFA‐producer Lachnospira and decrease in the pro‐inflammatory Enterobacteriaceae (FDR<0.25) compared to RG. Moreover, we found a PRE to POST increase in total stool SCFA, acetate, and acetate/propionate ratio (p<0.05) in WG versus RG. At week 6, Lachnospira positively associated with acetate and butyrate (FDR<0.25). Of the peripheral and stool immune and inflammatory markers investigated, WG relative to RG significantly increased total number of effector memory T cells and LPS‐stimulated ex vivo production of TNF‐α (p<0.05). These changes positively associated with plasma ARs concentrations, suggesting that the observed effects resulted from higher WG consumption. In summary, 6‐wk consumption of a diet rich in WG compared to RG, when dietary components and body weight are kept constant, increased stool weight and frequency, populations of some beneficial bacteria, number of effector memory T cells, and acute innate immune response; while, having no effect on other measures of cell‐mediated immunity or systemic and stool inflammatory markers. Support or Funding Information Supported by General Mills and USDA contract # 58‐1950‐0‐014.

Whole grain‐rich diets are consistently associated with lower adiposity in observational studies. However, clinical trials have failed to substantiate this association or identify underlying mechanisms. The inconsistency has been suggested to be due to trial methodology including suboptimal dietary control and confounding due to body weight changes. This study was designed to determine the effects of substituting whole grains for refined grains in the diet on adiposity and energy metabolism parameters independent of body weight change. Following a 2‐wk provided‐food run‐in period (0 g whole grains/d, 21 ± 3 g fiber/d), 81 men and post‐menopausal women (40–65 yr, BMI < 35.0 kg/m ² ) were randomly assigned to consume one of two provided‐food weight‐maintenance diets for 6 wk. The diets differed in whole grain and fiber contents (WG [n = 41]: 207 ± 39 g whole grains/d, 40 ± 5 g fiber/d or RG [n = 40]: 0 g whole grains/d, 21 ± 3 g fiber/d), but were otherwise similar in energy and macronutrient composition, types of provided foods and meal structure. Plasma alkylresorcinols (AR), biomarkers of WG intake, were measured at the end of the run‐in (PRE) and intervention (POST) periods to assess diet adherence. Body composition was measured by air displacement plethysmography, resting metabolic rate (RMR) and respiratory quotient (RQ) by indirect calorimetry, and fecal energy content by bomb calorimetry PRE and POST. Hunger and satiety were assessed weekly using visual analog scales. PRE plasma AR did not differ between groups but were higher POST in WG versus RG (p < 0.001). Body weight was maintained throughout the intervention in both groups. Changes in fat mass, fat‐free mass, RQ, and fecal energy density did not differ significantly between groups. However, changes in RMR ([WG versus RG mean difference ± SE] 48 ± 23 kcal/d; p = 0.04), fecal weight (76 ± 12 g/d; p < 0.001), and fecal energy content (96 ± 18 kcal/d; p < 0.001) were greater in WG versus RG. Additionally, perceived hunger (p = 0.06) and prospective consumption (p = 0.07) trended towards being lower in WG compared to RG. Collectively, these findings indicated that dietary substitution of whole grains for refined grains, in amounts that exceeded national dietary recommendations while increasing dietary fiber intake to recommended levels, did not impact body composition over 6 wk during weight maintenance, but conferred favorable energetic effects that cumulatively resulted in a 135 kcal/d energy deficit and reduced hunger. These findings provide mechanistic evidence supporting the consistent inverse associations between whole grain intakes and adiposity documented in observational studies which have been unsubstantiated in previous clinical trials that lacked dietary control or were confounded by concomitant weight loss. Support or Funding Information Funded by General Mills and by the USDA/ARS under agreement #8050‐15000‐097‐01S.

Abstract Observational studies suggest an association between diets rich in whole grains (WG) and a decrease in inflammatory markers. Yet, this is not clearly supported by the conflicting or limited number of interventional studies, few of which have included markers of cell-mediated immunity, which are important functional aspects of the immune system. Furthermore, WG consumption is often accompanied by weight loss, which may impact immune and inflammatory markers independent of a WG effect. This study was designed to maintain weight while investigating the effect of a WG rich diet versus refined grains (RG) on immune and inflammatory responses, gut microbiota, and microbial products. Following a 2-wk provided-food run-in period, 49 men and 32 post-menopausal women (40–65 yr, BMI < 35.0 kg/m2) were randomly assigned to one of two provided-food weight-maintenance diets for 6 weeks. The diets differed in WG and fiber contents (WG [n=41]: 207±39 g WG/d, 40±5 g fiber/d; or RG [n=40]: 0 g WG/d, 21±3 g fiber/d), but were similar in energy and meal structure. Relative abundances of gut bacteria were measured using DNA extracted from stool samples collected at PRE and POST, and by high-throughput sequencing of amplicons of the V4 region of the 16S rRNA gene. To assess the impact of WG on immune and inflammatory markers we measured a panel of inflammatory markers, phenotypic, and functional aspects of the immune system. Compliance was assessed by measuring biomarkers of WG intake, plasma alkylresorcinols (ARs), at the end of the run-in (PRE) and end of week-6 (POST) periods. We observed a significant increase in PRE to POST plasma ARs concentration in the WG group, and the PRE to POST change in plasma ARs was significantly higher in the WG compared to the RG (p< 0.001). Consumption of WG versus RG significantly increased 72h stool weight (p<0.001) and frequency (p=0.002). We noted a modest effect on gut microbiota and short chain fatty acid (SCFA): WG consumption resulted in a trend towards a decrease in Firmicutes and increase in Bacteroidetes and Fusobacteria POST intervention (FDR<0.30), and a significant increase in PRE to POST change in the SCFA-producer Lachnospira and decrease in the pro-inflammatory Enterobacteriaceae (FDR<0.25) compared to RG. Moreover, we found a PRE to POST increase in total stool SCFA, acetate, and acetate/propionate ratio (p<0.05) in WG versus RG. At week 6, Lachnospira positively associated with acetate and butyrate (FDR<0.25). Of the peripheral and stool immune and inflammatory markers investigated, WG relative to RG significantly increased total number of effector memory T cells and LPS-stimulated ex vivo production of TNF-α (p<0.05). These changes positively associated with plasma ARs concentrations, suggesting that the observed effects resulted from higher WG consumption. In summary, 6-wk consumption of a diet rich in WG compared to RG, when dietary components and body weight are kept constant, increased stool weight and frequency, populations of some beneficial bacteria, number of effector memory T cells, and acute innate immune response; while, having no effect on other measures of cell-mediated immunity or systemic and stool inflammatory markers. Support or Funding Information Supported by General Mills and USDA contract # 58-1950-0-014.

Vancomycin resistant Enteroccoci (VRE) are endemic in healthcare settings. These organisms colonize the gastrointestinal tract and can lead to infection which is associated with increased mortality. There is no treatment for VRE colonization. We conducted a randomized, double-blind, placebo controlled clinical trial to examine the safety and efficacy of administration of the probiotic Lactobacillus rhamnosus GG (LGG) for the reduction or elimination of intestinal colonization by VRE. Colonized adults were randomized to receive LGG or placebo for 14 days. Quantitative stool cultures for LGG and VRE were collected at baseline and days 7, 14, 21, 28 and 56. Day 14 stool samples from some subjects were analyzed by qPCR for LGG. Patients were closely monitored for adverse events. Eleven subjects were analyzed, of whom 5 received LGG and 6 placebo. No differences in VRE colony counts were seen at any time points between groups. No decline in colony counts was seen over time in subjects who received LGG. LGG was detected by PCR in all samples tested from subjects who received LGG but was only isolated in culture from 2 of 5 subjects in the LGG group. No treatment-related adverse events were seen. We demonstrated that LGG could be administered safely to patients with comorbidities, and is recoverable in some patients' stool cultures. Concomitant administration of antibiotics may have resulted in inability to recover viable organisms from stool, but LGG DNA could still be detected by qPCR. LGG administration did not affect VRE colonization in this study. Copyright © 2015, American Society for Microbiology. All Rights Reserved.