Springer Science and Business Media LLC

Glutathione (GSH), the most abundant endogenous antioxidant, is a critical regulator of oxidative stress and immune function. While oral GSH has been shown to be bioavailable in laboratory animal models, its efficacy in humans has not been established. Our objective was to determine the long-term effectiveness of oral GSH supplementation on body stores of GSH in healthy adults. A 6-month randomized, double-blinded, placebo-controlled trial of oral GSH (250 or 1,000 mg/day) on GSH levels in blood, erythrocytes, plasma, lymphocytes and exfoliated buccal mucosal cells was conducted in 54 non-smoking adults. Secondary outcomes on a subset of subjects included a battery of immune markers. GSH levels in blood increased after 1, 3 and 6 months versus baseline at both doses. At 6 months, mean GSH levels increased 30–35 % in erythrocytes, plasma and lymphocytes and 260 % in buccal cells in the high-dose group (P < 0.05). GSH levels increased 17 and 29 % in blood and erythrocytes, respectively, in the low-dose group (P < 0.05). In most cases, the increases were dose and time dependent, and levels returned to baseline after a 1-month washout period. A reduction in oxidative stress in both GSH dose groups was indicated by decreases in the oxidized to reduced glutathione ratio in whole blood after 6 months. Natural killer cytotoxicity increased >twofold in the high-dose group versus placebo (P < 0.05) at 3 months. These findings show, for the first time, that daily consumption of GSH supplements was effective at increasing body compartment stores of GSH.

Epidemiological evidence concerning the relationship between calcium and vitamin D intake and breast cancer (BC) is inconclusive. Moreover, the association according to menopausal status remains unclear. We aimed to assess whether total intakes from dietary and supplemental sources of calcium and vitamin D were associated with the incidence of BC in a Mediterranean cohort. We prospectively evaluated the association between intakes of calcium and vitamin D and BC risk among 10,812 women in the Seguimiento Universidad de Navarra (SUN) Project, a Spanish cohort of university graduates. During a mean follow-up of 10.7 years, 101 incident BC cases were confirmed. Evidence of a non-linear association between total calcium intake and BC risk was found (Pnon-linearity = 0.011) with risk reductions associated with higher intake up to approximately 1400 mg/day. Moderate intake [Tertile 2 (T2)] of total calcium was associated with lower overall BC risk [HR for T2 vs. Tertile 1 (T1): 0.55; 95% CI 0.33–0.91] and also among postmenopausal women (HRT2 vs. T1 = 0.38; 95% CI 0.16–0.92). Intake of vitamin D was not associated with BC risk. Our findings suggest an L-shaped association between total calcium intake and BC incidence. Moderate calcium intake may be associated with lower BC risk among overall and postmenopausal women, but not among premenopausal women. No evidence for any association between vitamin D intake and BC was found. Adherence to current guidelines recommendations for calcium intake may help to reduce BC risk.

Short-chain fatty acids (SCFAs) formation by intestinal bacteria is regulated by many different factors, among which dietary fibre is currently receiving most attention. However, since fibre-rich foods are usually good dietary sources of phenolic compounds, which are also known to affect the microbiota, authors hypothesize that the regular intake of these bioactive compounds could be associated with a modulation of faecal SCFA production by the intestinal microbiota. In this work, food intake was recorded by means of a validated Food Frequency Questionnaire. Fibres were determined using Marlett food composition tables, and phenolic compounds were obtained from Phenol-Explorer Database. Analysis of SCFA was performed by gas chromatography–flame ionization/mass spectrometry and quantification of microbial populations in faeces by quantitative PCR. Klason lignin and its food contributors, as predictors of faecal butyrate production, were directly associated with Bacteroides and Bifidobacterium levels, as well as lignans with Bacteroides. Also, anthocyanidins, provided by strawberries, were associated with faecal propionate and inversely related to Lactobacillus group. These results support the hypothesis we put forward regarding the association between some vegetable foods (strawberries, pasta, lentils, lettuce and olive oil) and faecal SCFA. More studies are needed in order to elucidate whether these associations have been mediated by the bacterial modulatory effect of the bioactive compounds, anthocyanins, lignans or Klason lignin, present in foodstuffs.

The field of nutrition has evolved rapidly over the past century. Nutrition scientists and policy makers in the developed world have shifted the focus of their efforts from dealing with diseases of overt nutrient deficiency to a new paradigm aimed at coping with conditions of excess—calories, sedentary lifestyles and stress. Advances in nutrition science, technology and manufacturing have largely eradicated nutrient deficiency diseases, while simultaneously facing the growing challenges of obesity, non-communicable diseases and aging. Nutrition research has gone through a necessary evolution, starting with a reductionist approach, driven by an ambition to understand the mechanisms responsible for the effects of individual nutrients at the cellular and molecular levels. This approach has appropriately expanded in recent years to become more holistic with the aim of understanding the role of nutrition in the broader context of dietary patterns. Ultimately, this approach will culminate in a full understanding of the dietary landscape—a web of interactions between nutritional, dietary, social, behavioral and environmental factors—and how it impacts health maintenance and promotion.

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A multifunctional diet (MFD) targeting subclinical inflammation was developed as a tool to decrease risk factors for cardiometabolic disease in healthy “at-risk” individuals (BMI 25–33 kg/m2). MFD contains several components that are degraded in the colon by the microbiota, such as dietary fibers from rye, barley, oats and berries. It also contains soy beans, oily fish and plant stanols. In previous studies, we have observed improved cardiometabolic markers in healthy at-risk individuals after 4–8 week intake of MFD. However, whether these improvements can be associated with changes in the gut microbiota composition has not been investigated. In the present study, we analyzed the gut microbiota before and after an 8-week dietary intervention with MFD. Cardiometabolic at-risk individuals (n = 47), between 51 and 72 years old and with a BMI of 25–33 kg/m2, were given either the MFD or a control diet lacking the functional (“active”) components for 8 weeks in a parallel, randomized design. Next-generation sequencing of bacterial 16S rRNA genes was used to analyze the gut microbiota composition. The 8-week intervention with MFD did not significantly alter the gut microbiota composition at phylum or genus taxonomic levels, while LEfSE analysis identified increased abundance of Prevotella copri in the MFD group as compared to the control group. Treponema correlated positively with blood pressure. In contrast, Faecalibacterium showed a negative association with blood pressure, while Bilophila appeared to associate with a negative blood lipid profile. Taken together, results from the present study may be used in the further development of effective dietary concepts capable of reducing cardiometabolic risk markers in humans through a targeted modulation of the gut microbial community. Clinical Trials.gov NCT02148653.