Fiber Patterns in Young Adults Living in Different Environments (USA, Spain, and Tunisia). Anthropometric and Lifestyle Characteristics

Testicular dysfunction and "its recovery effect" after cadmium exposure

In recent years, with the acceleration of industrialization, the decline of male fertility caused by heavy metal pollution has attracted much attention. However, whether the inhibition of testicular function after cadmium exposure is reversible remains to be studied. In this study, we constructed rat models of cadmium exposure and dis-exposure, and collected relative samples to observe the changes of related indicators. The results showed that cadmium exposure could reduce the fertility, inhibit the hypothalamic-pituitary-testis axis and activate hypothalamic-pituitary-adrenal axis function, the testicular GR/PI3K-AKT/AMPK signal was abnormal, cell proliferation was inhibited and apoptosis was enhanced. Four weeks after the exposure was stopped, the fertility was still decreased, testicular testosterone synthesis and spermatogenesis were inhibited, cell proliferation was inhibited and apoptosis was enhanced, but all of them were reversed. After eight weeks of cadmium exposure, the above indicators were observed to return to normal. At the same time, by giving different concentrations of corticosterone to spermatogonium, we confirmed that corticosterone may regulate the proliferation and apoptosis of spermatogonium through GR/PI3K-AKT/AMPK signal. In this study, the reproductive toxicity of cadmium, a metal environmental pollutant, was analyzed in depth to provide a new theoretical and experimental basis for ensuring male reproductive health.

Associations between dietary fiber intake and mortality from all causes, cardiovascular disease and cancer: a prospective study

OBJECTIVE

Several studies suggest that dietary fiber intake may reduce mortality risk, but this might depend on the fiber types and the evidence regarding the role of soluble fiber or insoluble fiber on death risk remain limited and inconsistent. Therefore, this study aimed to comprehensively evaluate multiple types of dietary fiber intake on mortality from all causes, cardiovascular disease and cancer in the large-scale Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial.

METHODS

A multivariate Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

This study finally included 86,642 participants with 17,536 all-cause deaths, 4842 cardiovascular deaths and 5760 cancer deaths identified after a total of 1,444,068 follow-up years. After adjusting for potential confounders, dietary total fiber intake was statistically significantly inversely associated with all-cause death (Q5 vs Q1: HR 0.71, 95% CI 0.66-0.75; P for trend < 0.001), cardiovascular death (Q5 vs Q1: HR 0.73, 95% CI 0.65-0.83; P for trend < 0.001) and cancer mortality (Q5 vs Q1: HR 0.77, 95% CI 0.69-0.86; P for trend < 0.001). Similar results were observed for both insoluble and soluble fiber intake. Restricted cubic spline model analysis suggested that there was a nonlinear association of dietary fiber intake with mortality risk (all P for nonlinearity < 0.05).

CONCLUSIONS

In this large nationally representative sample of US adult population, intakes of total fiber, soluble fiber, and insoluble fiber were associated with lower risks of all-cause, cardiovascular and cancer mortality.

Economic versus nutritional viability: evaluation of the antioxidant potential of food bars sources of proteins of different production costs

Currently, noncommunicable diseases (NCDs) are the main public health problems, especially in social and economically vulnerable groups due to greater exposure to risk factors. Functional foods may help to prevent these conditions. However, their access is more limited for the lower income population. Therefore, it is necessary to develop foods with more affordable prices. This study aimed to develop low-cost protein bars with antioxidant properties, and to compare their antioxidant potential with that of more expensive protein bars. For the formulation of high-cost (HC) and low-cost (LC) bars, different dried fruits, seeds, and nuts were selected, which were nutritionally similar, but with different costs. After establishing the ingredients to be used, the formulations were developed and evaluated regarding taste, texture, and appearance. The final formulations were characterized by proximate composition, minerals, total content of carotenoids, phenolic compounds, antioxidant properties, and sensory acceptance. Unpaired Student t test was used to compare both formulations. LC bar presented higher content of total carotenoids and phenolics than HC bar. Both bars were sensorially accepted and presented antioxidant potential. However, the LC bar showed higher values for antioxidant potential. Thus, it is possible to develop healthy products with functional and economically accessible ingredients.

Boosting the value of insoluble dietary fiber to increase gut fermentability through food processing

Insoluble dietary fibers are typically known to be poorly fermented in the large intestine. However, their value may be high as evidence shows that important butyrogenic bacteria preferentially utilize insoluble substrates to support their energy needs. The objective of this study was to increase fermentability of an insoluble bran fiber (pearl millet) while keeping it mostly insoluble to promote bacteria in the community that rely on fermentable insoluble dietary fibers. Following pretests with different processing methods, a combination of microwave and enzymatic treatments were applied to isolated pearl millet fiber to increase its accessibility of gut bacteria. In vitro human fecal fermentation was conducted and analyses were made for short chain fatty acids and microbiota changes. Combined microwave and enzymatic processing increased the amount of insoluble fiber fermented in vitro from 36 to 59% of total dietary fiber, with a minor increase in soluble fiber (8%). Microwave/enzymatic processing doubled butyrate production and almost tripled acetate production at 6 h fermentation compared to the native millet fiber. 16S rRNA gene sequencing showed that the processing promoted a significant increase in Firmicutes/Bacteroidetes ratio compared to the native fiber with relative abundance increases in Blautia and Copprococcus genera and a decrease in Bacteroidetes. Overall, these data show that processing techniques can be used to increase the value of insoluble fiber, presumably by increasing accessibility of the fiber to degrading bacteria, and to support Firmicutes that preferentially compete on insoluble fibers.

Food consumption in Tunisian university students and its association with sociodemographic characteristics and lifestyle behaviours

OBJECTIVE

This study aimed to characterise food consumption among students at the University of Carthage (Tunisia), assessing quality of diet and main dietary patterns, and their association with potential conditioning factors.

DESIGN

Cross-sectional study. Participants self-reported food consumption in two 24-h recalls and information about sociodemographic, anthropometric and lifestyle characteristics such as BMI, birthplace, physical activity, eating places or kitchen appliances. Mediterranean Diet Score (MDS) and the Nutrient Rich Foods (NRF) index (NRF9.3) were used to assess diet quality. Exploratory factor analysis was conducted to identify eating patterns. Linear regression models were used to test the association of dietary patterns with the diet quality markers.

SETTING

Students at the University of Carthage, Tunisia.

PARTICIPANTS

132 students.

RESULTS

Almost 96 % of participants need shifts towards healthier food. Four main food patterns were identified 'Traditional food', 'Transitional food', 'European breakfast' and 'Western food'. 'Traditional food' was the first dietary model, positively associated with MDS and NRF9.3. Women showed higher adherence to 'European breakfast' and higher quality of diet by NRF9.3. Students eating out of home showed higher adherence to 'Western food', those who never kept a regular schedule of meals consumed lower amount of vegetables and tubers, and sedentary or low active students had a higher intake of ready-to-eat products.

CONCLUSIONS

Diet quality of the participating Tunisian students is inadequate, but traditional Mediterranean diet remains the main pattern in spite of the advanced transitional nutrition. Some lifestyle risk behaviours affecting quality of diet were identified in this work, which supports the youth's particular vulnerability.

The role of microbiota-gut-brain axis in neuropsychiatric and neurological disorders

Emerging evidence indicates that the gut microbiota play a crucial role in the bidirectional communication between the gut and the brain suggesting that the gut microbes may shape neural development, modulate neurotransmission and affect behavior, and thereby contribute to the pathogenesis and/or progression of many neurodevelopmental, neuropsychiatric, and neurological conditions. This review summarizes recent data on the role of microbiota-gut-brain axis in the pathophysiology of neuropsychiatric and neurological disorders including depression, anxiety, schizophrenia, autism spectrum disorders, Parkinson's disease, migraine, and epilepsy. Also, the involvement of microbiota in gut disorders co-existing with neuropsychiatric conditions is highlighted. We discuss data from both in vivo preclinical experiments and clinical reports including: (1) studies in germ-free animals, (2) studies exploring the gut microbiota composition in animal models of diseases or in humans, (3) studies evaluating the effects of probiotic, prebiotic or antibiotic treatment as well as (4) the effects of fecal microbiota transplantation.

Nutritional quality and carbon footprint of university students' diets: results from the EHU12/24 study

Objective:

To evaluate diets in terms of nutritional characteristics and quality from the perspectives of health, greenhouse gas emissions (GHGE) and possible associations with each other in a representative sample of students at a public university.

Design:

Cross-sectional. Dietary intake was evaluated with a validated FFQ, and diet quality was assessed through the Healthy Eating Index (HEI-2010) and MedDietScore (MDS). GHGE data were obtained from the literature. In addition, sex, socio-economic status (SES) and body fat (BF) status were analysed as covariates.

Setting:

Basque Autonomous Community, Spain.

Participants:

Totally, 26 165 healthy adults aged 18–28 years.

Results:

Student diets were characterised by low consumption of carbohydrates (38·72 % of total energy intake (TEI)) and a high intake of lipids (39·08 % of TEI). Over half of the participants had low dietary quality. The low-emitting diets were more likely to be consumed by subjects with low HEI-2010 scores (β: 0·039 kg eCO₂/1000 kcal/d) and high MDS scores (β: −0·023 kg eCO₂/1000 kcal/d), after controlling for sex, SES and BF status. Both the low-emitting and healthy diets were more likely to be consumed by women and by those with normal BF percentage.

Conclusions:

UPV/EHU university students’ diets were characterised by moderate quality from a nutritional perspective and moderate variation in the size of carbon footprints. In this population, diets of the highest quality were not always those with the lowest diet-related GHGE; this relationship depended in part on the constructs and scoring criteria of diet quality indices used.

Risk factors of overweight/obesity-related lifestyles in university students: Results from the EHU12/24 study

This paper investigates the prevalence and interaction of overweight/obesity-related lifestyles (specifically, examining whether subjects meet the recommended criteria), in a representative sample of university students. This study is part of the project EHU12/24, an observational cross-sectional study, designed to assess the prevalence of excess body fat (BF) and major risk of developing overweight/obesity, according to a standardised protocol. In a cohort of 603 students, aged between 18 and 28 years, of the University of the Basque Country, information about meal patterns, diet quality, physical activity, sitting time, sleeping time, toxic habits and anthropometric measurements were collected. Sampling took place from February 2014 to May 2017. Binary logistic regression models adjusted for the covariates were utilised to test the association between lifestyles and risk of excess adiposity. The prevalence of overweight/obesity, according to BF percentage, was 14·4 %. The variables analysed related to meal pattern were associated with diet quality, and less healthy food habits were associated with other less health-related behaviours. Among men, moderate/low physical activity, breakfast skipping, non-adequate breakfast duration, number of eating occasions and eating breakfast alone/depending on the occasion were associated with excess BF, while among women, low MedDietScore, moderate/high alcohol consumption, non-adequate sleep duration, eating breakfast and lunch alone/depending on the occasion. Results suggest that certain unhealthy lifestyle behaviours coexist, interact with one another and increase the risk of overweight/obesity in this population. Sex-specific differences in risk factors of obesity have implications for interventions for primary prevention of obesity within this environment.

Relevance of body mass index and bioelectrical impedance analysis vs. deuterium dilution technique to assess excess of fat among young adults

Our study aimed to assess the nutritional status by using body composition among young Tunisian adults through three measurement methods: body mass index (BMI), bioelectrical impedance analysis (BIA) and deuterium oxide dilution technique (²H₂O) and to determine the accuracy of BMI and BIA in order to evaluate the overweight and obesity among young adults in Tunisia. Our study involved 144 young adults. Anthropometric parameters were measured. The fat mass percentage (%FM) was determined by ²H₂O and BIA techniques. The analysis of deuterium enrichment was performed using a Fourier transform infrared spectrophotometer (FTIR). According to BMI, 26.4% of subjects were overweight and 5.5% were obese. The mean of %FM estimated by BIA was significantly higher than that determined by ²H₂O (29.7 ± 7.7 vs. 26.3 ± 10.6, p < .0001). Consequently, the prevalence of overweight and obesity assessed by BIA was significantly higher than by ²H₂O (51.4% vs. 34%, p < .0001). Using BMI, the prevalence of overweight and obesity was similar to that estimated by ²H₂O (31.9% vs. 34%, p = 0.544). Compared to ²H₂O, BIA overestimates the prevalence of overweight and obesity in young adults. On the other hand, the BMI showed an interesting correlation with the %FM determined by ²H₂O.

Meta-Analysis and Systematic Review of Micro- and Macro-Nutrient Intakes and Trajectories of Macro-Nutrient Supply in the Eastern Mediterranean Region

The Eastern Mediterranean Region (EMR) is experiencing a nutrition transition, characterized by the emergence of overnutrition and micro-nutrient deficiencies. No previous study has comparatively examined nutrient intake in adults across countries in the EMR. This review examined the adequacy of nutrients in adults living in the EMR. Moreover, it analyzed the food balance sheets (FBS) for 1961–2018 to identify the trajectory of energy supply from macro-nutrients in the EMR. A systematic search was conducted from January 2012 to September 2020. Only observational studies were retained with a random sampling design. An assessment of the methodological quality was conducted. Levels of nutrient daily intake and their adequacy compared to the daily reference intake of the Institute of Medicine were reported across the region. No studies were identified for half of the region’s countries. Although nutrient energy intake was satisfactory overall, fat and carbohydrate intake were high. Intake of vitamin D, calcium, potassium, zinc, and magnesium were below that recommended. The analysis of the FBS data allowed for the identification of four linear patterns of trajectories, with countries in the EMR best fitting the ‘high-energy-supply from carbohydrate’ group. This systematic review warrants multi-sectorial commitment to optimize nutrient intake.

Role of Short Chain Fatty Acids and Apolipoproteins in the Regulation of Eosinophilia-Associated Diseases

Eosinophils are key components of our host defense and potent effectors in allergic and inflammatory diseases. Once recruited to the inflammatory site, eosinophils release their cytotoxic granule proteins as well as cytokines and lipid mediators, contributing to parasite clearance but also to exacerbation of inflammation and tissue damage. However, eosinophils have recently been shown to play an important homeostatic role in different tissues under steady state. Despite the tremendous progress in the treatment of eosinophilic disorders with the implementation of biologics, there is an unmet need for novel therapies that specifically target the cytotoxic effector functions of eosinophils without completely depleting this multifunctional immune cell type. Recent studies have uncovered several endogenous molecules that decrease eosinophil migration and activation. These include short chain fatty acids (SCFAs) such as butyrate, which are produced in large quantities in the gastrointestinal tract by commensal bacteria and enter the systemic circulation. In addition, high-density lipoprotein-associated anti-inflammatory apolipoproteins have recently been shown to attenuate eosinophil migration and activation. Here, we focus on the anti-pathogenic properties of SCFAs and apolipoproteins on eosinophil effector function and provide insights into the potential use of SCFAs and apolipoproteins (and their mimetics) as effective agents to combat eosinophilic inflammation.

Not All Fibers Are Born Equal; Variable Response to Dietary Fiber Subtypes in IBD

Diet provides a safe and attractive alternative to available treatment options in a variety of diseases; however, research has only just begun to elucidate the role of diet in chronic diseases, such as the inflammatory bowel diseases (IBD). The chronic and highly debilitating IBDs, Crohn disease and ulcerative colitis, are hallmarked by intestinal inflammation, immune dysregulation, and dysbiosis; and evidence supports a role for genetics, microbiota, and the environment, including diet, in disease pathogenesis. This is true especially in children with IBD, where diet-based treatments have shown excellent results. One interesting group of dietary factors that readily links microbiota to gut health is dietary fibers. Fibers are not digested by human cells, but rather fermented by the gut microbes within the bowel. Evidence has been mounting over the last decade in support of the importance of dietary fibers in the maintenance of gut health and in IBD; however, more recent studies highlight the complexity of this interaction and importance of understanding the role of each individual dietary fiber subtype, especially during disease. There are roughly ten subtypes of dietary fibers described to date, categorized as soluble or insoluble, with varying chemical structures, and large differences in their fermentation profiles. Many studies to date have described the benefits of the byproducts of fermentation in healthy individuals and the potential health benefits in select disease models. However, there remains a void in our understanding of how each of these individual fibers affect human health in dysbiotic settings where appropriate fermentation may not be achieved. This review highlights the possibilities for better defining the role of individual dietary fibers for use in regulating inflammation in IBD.

Dietary fiber intake and the risk of bladder cancer in the Prostate, Lung, Colorectal and Ovarian (PLCO) cohort

Dietary fiber intake has been implicated as a protective factor for several human cancers in multiple epidemiologic studies. However, little is known about the effect of fiber intake on bladder cancer. This study examines the association between dietary fiber intake and bladder cancer risk among participants in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. A total of 101 721 participants were included in this study as they completed both the baseline questionnaire and the diet history questionnaire (cancer free before completion of the diet history questionnaire). Hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) were estimated using the Cox proportional hazards regression model. After a median of 12.5 years of follow-up, 776 new cases of bladder cancer were identified. Higher intake of total fiber, insoluble fiber and soluble fiber were not significantly associated with a reduced risk of bladder cancer. The multi-adjusted HRs (95 CIs) of highest versus lowest tertile of intake were 0.83 (0.66-1.04) for total fiber (P for trend = 0.098), 0.83 (95% CI: 0.67-1.03) for insoluble fiber (P for trend = 0.092) and 0.86 (95% CI: 0.68-1.08) for soluble fiber (P for trend = 0.168), respectively. There was no significant interaction of potential confounders, including education, body mass index and smoking status, with total fiber intake on bladder cancer risk. In summary, the findings of this prospective study show that there is no obvious evidence for a link between dietary fiber consumption and bladder cancer risk. Further large cohort studies are warranted to confirm these findings.

New View on Dietary Fiber Selection for Predictable Shifts in Gut Microbiota

Dietary fibers can be utilized to shape the human gut microbiota. However, the outcomes from most dietary fibers currently used as prebiotics are a result of competition between microbes with overlapping abilities to utilize these fibers. Thus, divergent fiber responses are observed across individuals harboring distinct microbial communities. Here, we propose that dietary fibers can be classified hierarchically according to their specificity toward gut microbes. Highly specific fibers harbor chemical and physical characteristics that allow them to be utilized by only a narrow group of bacteria within the gut, reducing competition for that substrate. The use of such fibers as prebiotics targeted to specific microbes would result in predictable shifts independent of the background microbial composition.

Oat Bran Increased Fecal Butyrate and Prevented Gastrointestinal Symptoms in Patients With Quiescent Ulcerative Colitis-Randomized Controlled Trial

Background

Oat bran specifically increases colon butyrate concentrations and could therefore affect the progress of the disease in patients with ulcerative colitis (UC).

Methods

Patients with UC in remission were enrolled in a controlled multicenter study and randomized to eat oat bran or low-fiber wheat products.

Results

Ninety-four of the enrolled patients (n = 47 for both groups) completed the 24-week study. The oat bran group had significantly (P < 0.05) higher fecal butyrate concentrations and lower serum LDL levels, while deterioration of gastrointestinal symptoms was prevented, and subjective health maintained. The control diet significantly (P < 0.05) increased obstipation, reflux, and the symptom burden and had no effects on butyrate or LDL-cholesterol. The relapse rate was the same for both diets.

Conclusions

Oat bran was well tolerated when given to patients with quiescent UC.

Diet quality and nutrient density in subjects with metabolic syndrome: Influence of socioeconomic status and lifestyle factors. A cross-sectional assessment in the PREDIMED-Plus study

BACKGROUND

Socioeconomic disparities and lifestyle factors are likely to determine the overall quality of the diet. In addition, overeating is compatible with inadequate micronutrient intake and it can lead to adverse health outcomes.

OBJECTIVE

To assess adequacy of dietary nutrient intake and to investigate the influence of socioeconomic and lifestyle factors on nutrient density in a large primary cardiovascular prevention trial conducted in healthy participants with metabolic syndrome (MetS) to assess the cardiovascular effects of an energy-restricted Mediterranean diet (PREDIMED-Plus).

METHODS

Baseline cross-sectional analysis of the PREDIMED-Plus trial with 6646 Spanish participants (aged 55-75 years in men and 60-75 years in women) with overweight/obesity and MetS. Energy and nutrient intake (for 10 nutrients) were calculated using a validated 143-item Food Frequency Questionnaire (FFQ) and nutrient density was estimated dividing the absolute nutrient intake by total energy intake. The prevalence of inadequate intake was estimated according to dietary reference intakes. Multivariable linear regression models were fitted to examine associations between socioeconomic status or lifestyle factors and nutrient density.

RESULTS

A considerable proportion of the screened participants showed a deficient intake of vitamins A, D, E, B₉, calcium, magnesium and dietary fibre. Inadequate intake of four or more of the ten nutrients considered was present in 17% of participants. A higher nutrient density was directly and significantly associated with female sex, higher educational level and a better adherence to the Mediterranean diet. Lifestyle factors such as non-smoking and avoidance of sedentary lifestyles were also independently associated with better nutrient density.

CONCLUSIONS

Patients with MetS, despite being overweight, exhibited suboptimal nutrient intake, especially among men. Low nutrient density diet can be largely explained by differences in socioeconomic and lifestyle factors. These results highlight the importance of focussing on nutritional education in vulnerable populations, taking into account nutrient requirements.

Diet, physical activity and screen time but not body mass index are associated with the gut microbiome of a diverse cohort of college students living in university housing: a cross-sectional study

BACKGROUND

Modifiable lifestyle factors (e.g. dietary intake and physical activity) are important contributors to weight gain during college. The purpose of this study was to evaluate whether associations exist between body mass index, physical activity, screen time, dietary consumption (fat, protein, carbohydrates, and fiber), and gut microbial diversity during the first year of college. Racially/ethnically diverse college students (n = 82; 61.0% non-white) at a large Southwestern university completed self-reported physical activity and 24-h recall dietary assessments, height and weight measurements, and provided one fecal sample for gut microbiome analysis. Fecal microbial community composition was assessed with Illumina MiSeq next-generation sequencing of PCR amplified 16S rRNA genes. Post-hoc analyses compared microbial diversity by groups of high and low physical activity and fiber intake using QIIME and LEfSe bioinformatics software.

RESULTS

No statistically significant differences were observed between body mass index and gut microbiome abundance and diversity. Median daily consumption of dietary fiber was 11.2 (7.6, 14.9) g/d, while the median self-reported moderate-to-vigorous physical activity (MVPA) was 55.7 (27.9, 79.3) min/d and screen time 195.0 (195.0, 315.0) min/d. Microbial analysis by LEfSe identified Paraprevotellaceae, Lachnospiraceae, and Lachnospira as important phylotypes in college students reporting greater MVPA, while Enterobacteriaceae and Enterobacteriales were more enriched among students reporting less MVPA (p < 0.05). Barnesiellaceae, Alphaproteobacteria, and Ruminococcus were more abundant taxa among those consuming less than the median fiber intake (p < 0.05). Post-hoc analyses comparing weighted UniFrac distance metrics based on combined categories of high and low MVPA and fiber revealed that clustering distances between members of the high MVPA-low fiber group were significantly smaller when compared to distances between members of all other MVPA-fiber groups (p < 0.0001).

CONCLUSIONS

Habitual fiber consumption and MVPA behaviors help explain the differential abundance of specific microbial taxa and overall gut microbial diversity differences in first-year college students.