Compared with the intake of commercial vegetable juice, the intake of fresh fruit and komatsuna (Brassica rapa L. var. perviridis) juice mixture reduces serum cholesterol in middle-aged men: a randomized controlled pilot study

Brassica rapa L. prevents Western diet-induced obesity in C57BL/6 mice through its binding capacity of cholesterol and fat

Obesity, a chronic disorder caused by excessive energy intake leading to fat accumulation in adipose tissue, increases the risk of severe diseases. Brassica rapa L. is known as a traditional vegetable in the Nagano area of Japan. C57BL/6 mice were randomly assigned to three groups, with different diets as follows: a normal diet, a Western diet (WD), and a WD plus B. rapa L. powder (BP) in a 56-day experiment. Brassica rapa L. supplementation reduced the body weight gain and lipid accumulation of mice significantly. The BP group also had higher fecal bile acid, total cholesterol, and triglyceride excretion levels compared with those in the other groups. The antiobesity effects of B. rapa L. were due to its binding with cholesterol and fat, and possibly enhancing the bile acid excretion and modulating gut microbiota, suggesting that B. rapa L. could be a functional vegetable with potential uses in targeting obesity.

How to write statistical analysis section in medical research

Reporting of statistical analysis is essential in any clinical and translational research study. However, medical research studies sometimes report statistical analysis that is either inappropriate or insufficient to attest to the accuracy and validity of findings and conclusions. Published works involving inaccurate statistical analyses and insufficient reporting influence the conduct of future scientific studies, including meta-analyses and medical decisions. Although the biostatistical practice has been improved over the years due to the involvement of statistical reviewers and collaborators in research studies, there remain areas of improvement for transparent reporting of the statistical analysis section in a study. Evidence-based biostatistics practice throughout the research is useful for generating reliable data and translating meaningful data to meaningful interpretation and decisions in medical research. Most existing research reporting guidelines do not provide guidance for reporting methods in the statistical analysis section that helps in evaluating the quality of findings and data interpretation. In this report, we highlight the global and critical steps to be reported in the statistical analysis of grants and research articles. We provide clarity and the importance of understanding study objective types, data generation process, effect size use, evidence-based biostatistical methods use, and development of statistical models through several thematic frameworks. We also provide published examples of adherence or non-adherence to methodological standards related to each step in the statistical analysis and their implications. We believe the suggestions provided in this report can have far-reaching implications for education and strengthening the quality of statistical reporting and biostatistical practice in medical research.

Dietary Supplementation with Fermented Brassica rapa L. Stimulates Defecation Accompanying Change in Colonic Bacterial Community Structure

Our previous studies have elucidated that oral administration of Brassica rapa L. extract, known as Nozawana in Japan, alters immune responses and gut microbiota composition, increasing the numbers of butyrate-producing bacteria. Therefore, further investigation would help elucidate the mechanism attributable for the changes and health-promoting effects observed after B rapa L. extract ingestion. To reveal the modulation effects of fermented B. rapa L. on immune function and intestinal bacterial community structure, we conducted an intervention study with healthy volunteers followed by a mouse feeding study. The pilot intervention study was conducted for healthy volunteers aged 40–64 years under the hypothesis that the number of subjects exhibiting any change in gut microbiota in response to fermented B. rapa L. consumption may be limited. In total, 20 volunteers consumed 30 g of fermented B. rapa L. per day for 4 weeks. The fecal bacterial community composition of the volunteers was characterized using terminal-restriction fragment length polymorphism patterning followed by clustering analysis. To evaluate the detailed changes in the immune responses and the gut bacterial composition, assessed by high-throughput sequencing, we fed healthy mice with freeze-dried, fermented B. rapa L. for 2 weeks. The fecal bacterial community composition of the volunteers before the intervention was divided into three clades. Regardless of the clade, the defecation frequency significantly increased during the intervention weeks compared with that before the intervention. However, this clustering detected a specific increase of Prevotella in one cluster (low to zero Prevotella and high occupation of Clostridium at clusters IV and XIVa) post-ingestion. The cytokine production of spleen cells significantly increased due to feeding fermented B. rapa L. to the mice. This supplementary in vivo trial provided comparable results to the volunteer study regarding the effects of ingestion of the material given the compositional change complying with that of dietary fiber, particularly in the increase of genera Prevotella, Lachnospira, and genera in the Ruminococcaceae family, and the increase in daily defecation amount during 2 weeks of administration. We conclude that feeding fermented B. rapa L. may be responsible for the observed modulation in gut microbiota to increase fiber-degrading bacteria and butyrate-producing bacteria which may be relevant to the improvement in bowel function such as defecation frequency.

Eruca sativa Mill. seed extract promotes anti-obesity and hypoglycemic effects in mice fed with a high-fat diet

Obesity is currently considered a major source of morbidity, with dramatic complications on health status and life expectancy. Several studies demonstrated the positive effects of Brassicaceae vegetables on obesity and related diseases, partially attributing these beneficial properties to glucosinolates and their derivatives isothiocyanates. Recently, isothiocyanates have been described as a hydrogen sulfide (H₂ S)-releasing moiety, suggesting that H₂ S may be at least in part responsible for the beneficial effects of Brassicaceae. In this work, the metabolic effects of an extract obtained from Eruca sativa Mill. seeds (E.S., Brassicaceae), containing high levels of glucoerucin, were evaluated in an experimental model of obesity. Male balb/c mice were fed for 10 weeks with standard (Std) diet or high fat (HF) diet supplemented with E.S. E.S. significantly contained the body weight gain in this obesity model, improving also glucose homeostasis. Interestingly, lower values of white adipose tissue mass and a significant reduction of adipocytes size were also observed. Moreover, E.S. enhanced the adipocytes metabolism, improving the citrate synthase activity and reduced triglyceride levels in mice fed with HF diet. Taken together, these results suggest that E.S. is endowed with an interesting translational and nutraceutical value in the prevention of metabolic disorders, suggesting that H₂ S could be a key player.

Association of the Healthy Eating Index with Estimated Cardiovascular Age in Adults from the KNHANES 2013-2017

In this paper, we hypothesized that the gap between estimated cardiovascular age (eCV-age) and chronological age had a gender-wise correlation with the Korean Healthy Eating Index (KHEI). We tested the hypothesis in adults aged 20-64 years old using the KNHANES 2013-2017 data. eCV-age was estimated based on the designated risk factors of cardiovascular disease (CVD) and age-gap was calculated by subtracting the eCV-age from the chronological age in 12,317 adults. Adjusted odds ratios for the age-gap were measured according to KHEI, while controlling for covariates to influence risk factors of CVD, using logistic regression analysis with the complex sample survey design. Age-gaps were divided into four groups: >4 (High), 0-4 (Moderate), -4-0 (Mild), and <-4 years (Low). The higher the age-gap, the lower the cardiovascular risk. Persons included in the following categories belonged to the high and moderate age-gap groups: young (<40 years), women, urban living, better than high school education, higher income, lean, mild drinking, and exercising regularly. KHEI scores were overall higher in women than men (p < 0.01). Having breakfast and saturated fat intake were primary factors that influenced the age-gap for men, whereas fresh fruit intake and carbohydrate intake influenced the age-gap in women. The KHEI scores positively correlated with nutrient intake, especially fiber and vitamin C intake in women (p < 0.05). Participants with high KHEI scores increased their chances of belonging to the high age-gap group by 2.16 times for men and 2.10 for women after adjusting for covariates of sex, age, and residence. However, after adding the covariates of education, income, marriage, and obesity, in conjunction with smoking, alcohol, and regular exercise, this reduced to 1.34 times in women. In conclusion, both genders had a positive correlation between age-gap and overall KHEI scores.

Bacterial Protein Mimetic of Peptide Hormone as a New Class of Protein- based Drugs

Specific peptide molecules classified as hormones, neuropeptides and cytokines are involved in intercellular signaling regulating various physiological processes in all organs and tissues. This justifies the peptidergic signaling as an attractive pharmacological target. Recently, a protein mimetic of a peptide hormone has been identified in Escherichia coli suggesting the potential use of specific bacterial proteins as a new type of peptide-like drugs. We review the scientific rational and technological approaches leading to the identification of the E. coli caseinolytic protease B (ClpB) homologue protein as a conformational mimetic of α-melanocyte-stimulating hormone (α-MSH), a melanocortin peptide critically involved in the regulation of energy homeostasis in humans and animals. Theoretical and experimental backgrounds for the validation of bacterial ClpB as a potential drug are discussed based on the known E. coli ClpB amino acid sequence homology with α-MSH. Using in silico analysis, we show that other protein sources containing similar to E. coli ClpB α-MSH-like epitopes with potential biological activity may exist in Enterobacteriaceae and in some Brassicaceae. Thus, the original approach leading to the identification of E. coli ClpB as an α-MSH mimetic protein can be applied for the identification of mimetic proteins of other peptide hormones and development of a new type of peptide-like protein-based drugs.

Changes in Gut Microbial Ecology and Immunological Responses of Mice Fed the Insoluble Fraction of Brassica rapa L. that was Fermented or Not

We aimed to investigate the effects of feeding fermented Brassica rapa L. on ecological and immunological changes in the mouse gut using in vitro cultivation tests and in vivo experiments in normal mice. In the preliminary in vitro study, two B. rapa L. products from different fermentation periods (one d [SF] or six months [LF]) were evaluated along with non-fermented vegetables (NF). Among the components of each product, the insoluble fraction resulted in the most prominent change such as a relative increase in butyrate production during a cultivation inoculated with mouse cecum contents. Based on this result, the boiled water-insoluble fractions of B. rapa L. (SF, LF, and NF samples) were selected as test materials for the subsequent in vivo experiment. Male C57BL/6J mice were divided into four groups and fed either a control diet (CON) or control diet plus one of the insoluble fractions for two weeks. The NF and LF groups had higher relative populations of Faecalibacterium prausnitzii than the CON group. Therefore, colonic butyrate concentrations were higher in the NF and LF groups than in the CON group. The oral administration of B. rapa L. extract induced immune regulatory effects, even when mice were fed NF and SF, but not LF, as assessed by an increase in regulatory T cell numbers. Our results indicate that feeding a purified insoluble fraction from B. rapa L. affects enteric short-chain fatty acid production and immunological responses in the mouse gut in a similar manner, regardless of the fermentation status.

Effects and Mechanisms of Fruit and Vegetable Juices on Cardiovascular Diseases

Many studies have indicated that consumption of vegetables and fruits are positively related to lower incidence of several chronic noncommunicable diseases. Although composition of fruit and vegetable juices is different from that of the edible portion of fruits and vegetables, they contain polyphenols and vitamins from fruits and vegetables. Drinking vegetable and fruit juices is very popular in many countries, and also an efficient way to improve consumption of fruits and vegetables. The studies showed that fruit and vegetable juices affect cardiovascular risk factors, such as lowering blood pressure and improving blood lipid profiles. The main mechanisms of action included antioxidant effects, improvement of the aspects of the cardiovascular system, inhibition of platelet aggregation, anti-inflammatory effects, and prevention of hyperhomocysteinemia. Drinking juices might be a potential way to improve cardiovascular health, especially mixtures of juices because they contain a variety of polyphenols, vitamins, and minerals from different fruits and vegetables. This review summarizes recent studies on the effects of fruit and vegetable juices on indicators of cardiovascular disease, and special attention is paid to the mechanisms of action.

Relationship of Enhanced Butyrate Production by Colonic Butyrate-Producing Bacteria to Immunomodulatory Effects in Normal Mice Fed an Insoluble Fraction of Brassica rapa L

This study was performed to determine the effects of feeding a fiber-rich fraction of Brassica vegetables on the immune response through changes in enteric bacteria and short-chain fatty acid (SCFA) production in normal mice. The boiled-water-insoluble fraction of Brassica rapa L. (nozawana), which consists mainly of dietary fiber, was chosen as a test material. A total of 31 male C57BL/6J mice were divided into two groups and housed in a specific-pathogen-free facility. The animals were fed either a control diet or the control diet plus the insoluble B. rapa L. fraction for 2 weeks and sacrificed to determine microbiological and SCFA profiles in lower-gut samples and immunological molecules. rRNA-based quantification indicated that the relative population of Bacteroidetes was markedly lower in the colon samples of the insoluble B. rapa L. fraction-fed group than that in the controls. Populations of the Eubacterium rectale group and Faecalibacterium prausnitzii, both of which are representative butyrate-producing bacteria, doubled after 2 weeks of fraction intake, accompanying a marginal increase in the proportion of colonic butyrate. In addition, feeding with the fraction significantly increased levels of the anti-inflammatory cytokine interleukin-10 (IL-10) and tended to increase splenic regulatory T cell numbers but significantly reduced the population of cells expressing activation markers. We demonstrated that inclusion of the boiled-water-insoluble fraction of B. rapa L. can alter the composition of the gut microbiota to decrease the numbers of Bacteroidetes and to increase the numbers of butyrate-producing bacteria, either of which may be involved in the observed shift in the production of splenic IL-10.

Incorrect statistical method in parallel-groups RCT led to unsubstantiated conclusions

The article by Aiso et al. titled “Compared with the intake of commercial vegetable juice, the intake of fresh fruit and komatsuna (Brassica rapa L. var perviridis) juice mixture reduces serum cholesterol in middle-aged men: a randomized controlled pilot study” does not meet the expected standards of Lipids in Health and Disease. Although the article concludes that there are some significant benefits to their komatsuna juice mixture, these claims are not supported by the statistical analyses used. An incorrect procedure was used to compare the differences in two treatment groups over time, and a large number of outcomes were tested without correction; both issues are known to produce high rates of false positives, making the conclusions of the study unjustified. The study also fails to follow published journal standards regarding clinical trial registration and reporting.

Best (but oft forgotten) practices: testing for treatment effects in randomized trials by separate analyses of changes from baseline in each group is a misleading approach

Researchers often analyze randomized trials and other comparative studies by separate analysis of changes from baseline in each parallel group. This may be the only analysis presented or it may be in addition to the direct comparison of allocated groups. We illustrate this by reference to 3 recently published nutritional trials. We show why this method of analysis may be highly misleading and may produce type I errors far greater than the 5% that we expect. We recommend direct comparison of means between groups with the use of baseline as a covariate if required.

Diet rich in high glucoraphanin broccoli reduces plasma LDL cholesterol: Evidence from randomised controlled trials

SCOPE

Cruciferous-rich diets have been associated with reduction in plasma LDL-cholesterol (LDL-C), which may be due to the action of isothiocyanates derived from glucosinolates that accumulate in these vegetables. This study tests the hypothesis that a diet rich in high glucoraphanin (HG) broccoli will reduce plasma LDL-C.

METHODS AND RESULTS

One hundred and thirty volunteers were recruited to two independent double-blind, randomly allocated parallel dietary intervention studies, and were assigned to consume either 400 g standard broccoli or 400 g HG broccoli per week for 12 weeks. Plasma lipids were quantified before and after the intervention. In study 1 (37 volunteers), the HG broccoli diet reduced plasma LDL-C by 7.1% (95% CI: -1.8%, -12.3%, p = 0.011), whereas standard broccoli reduced LDL-C by 1.8% (95% CI +3.9%, -7.5%, ns). In study 2 (93 volunteers), the HG broccoli diet resulted in a reduction of 5.1% (95% CI: -2.1%, -8.1%, p = 0.001), whereas standard broccoli reduced LDL-C by 2.5% (95% CI: +0.8%, -5.7%, ns). When data from the two studies were combined the reduction in LDL-C by the HG broccoli was significantly greater than standard broccoli (p = 0.031).

CONCLUSION

Evidence from two independent human studies indicates that consumption of high glucoraphanin broccoli significantly reduces plasma LDL-C.