Vitamin B consists of a group of water-soluble micronutrients that are mainly derived from the daily diet. They serve as cofactors, mediating multiple metabolic pathways in humans. As an integrated part of human health, gut microbiota could produce, consume, and even compete for vitamin B with the host. The interplay between gut microbiota and the host might be a crucial factor affecting the absorbing processes of vitamin B. On the other hand, vitamin B supplementation or deficiency might impact the growth of specific bacteria, resulting in changes in the composition and function of gut microbiota. Together, the interplay between vitamin B and gut microbiota might systemically contribute to human health. In this review, we summarized the interactions between vitamin B and gut microbiota and tried to reveal the underlying mechanism so that we can have a better understanding of its role in human health.

BackgroundOverweight and obesity increase the risk of noncommunicable diseases (NCDs). Personalized nutrition (PN) approaches may provide tailored nutritional advice/service by focusing on individual's unique characteristics to prevent against NCDs.ObjectiveWe aimed to compare the effect of PN intervention with the traditional “one size fits all” intervention on health status in overweight/obese Chinese adults.MethodsIn this 12-week randomized controlled trial, 400 adults with BMI ≥24 kg/m2 were randomized to control group (CG, n = 200) and PN group (PNG, n = 200). The CG received conventional health guidance according to the Dietary Guidelines for Chinese Residents and Chinese DRIs Handbook, whereas the PNG experienced PN intervention that was developed by using decision trees based on the subjects' anthropometric measurements, blood samples (phenotype), buccal cells (genotype), and dietary and physical activity (PA) assessments (baseline and updated).ResultsCompared with the conventional intervention, PN intervention significantly improved clinical outcomes of anthropometric (e.g., body mass index (BMI), body fat percentage, waist circumference) and blood biomarkers (e.g., blood lipids, uric acid, homocysteine). The improvement in clinical outcomes was achieved through behavior change in diet and PA. The subjects in the PNG had higher China dietary guidelines index values and PA levels. Personalized recommendations of “lose weight,” “increase fiber” and “take multivitamin/mineral supplements” were the major contributors to the decrease of BMI and improvement of lipid profile.ConclusionWe provided the first evidence that PN intervention was more beneficial than conventional nutrition intervention to improve health status in overweight/obese Chinese adults. This study provides a model of framework for developing personalized advice in Chinese population.Chictr.org.cn (ChiCTR1900026226).

Phytonutrients are natural bioactive components present in the daily diet that can exert a positive impact on human health. Studies have shown that phytonutrients may act as antioxidants and improve metabolism after being ingested, which help to regulate physiological processes and prevent metabolic disorders and diseases. However, their efficacy is limited by their low bioavailability. The gut microbiota is symbiotic with humans and its abundance and profile are related to most diseases. Interestingly, studies have shown that the gut microbiota is associated with the metabolism of phytonutrients by converting them into small molecules that can be absorbed by the body, thereby enhancing their bioavailability. Furthermore, phytonutrients can modulate the composition of the gut microbiota, and therefore improve the host's health. Here, we focus on uncovering the mechanisms by which phytonutrients and gut microbiota play roles in health, and the interrelationships between phytonutrients and gut microbiota were summarized. We also reviewed the studies that reported the efficacy of phytonutrients in human health and the future directions.

Nutritional disorders have become a major public health issue, requiring increased targeted approaches. Personalized nutrition adapted to individual needs has garnered dramatic attention as an effective way to improve nutritional balance and maintain health. With the rapidly evolving fields of genomics and nutrigenetics, accumulation of genetic variants has been indicated to alter the effects of nutritional supplementation, suggesting its indispensable role in the genotype-based personalized nutrition. Additionally, the metabolism of nutrients, such as lipids, especially omega-3 polyunsaturated fatty acids, glucose, vitamin A, folic acid, vitamin D, iron, and calcium could be effectively improved with related genetic variants. This review focuses on existing literatures linking critical genetic variants to the nutrient and the ways in which these variants influence the outcomes of certain nutritional supplementations. Although further studies are required in this direction, such evidence provides valuable insights for the guidance of appropriate interventions using genetic information, thus paving the way for the smooth transition of conventional generic approach to genotype-based personalized nutrition.

Nutritional biomarkers can be used as important indicators of nutritional status and play crucial roles in the prevention as well as prognosis optimization of various metabolism-related diseases. Measuring dietary with the deployment of biomarker assessments provides quantitative nutritional information that can better predict the health outcomes. With the increased availability of nutritional biomarkers and the development of assessment tools, the specificity and sensitivity of nutritional biomarkers have been greatly improved. This enables efficient disease surveillance in nutrition research. A wide range of biomarkers have been used in different types of studies, including clinical trials, observational studies, and qualitative studies, to reflect the relationship between diet and health. Through a comprehensive literature search, we reviewed the well-established nutritional biomarkers of vitamins, minerals, and phytonutrients, and their association with epidemiological studies, to better understand the role of nutrition in health and disease.