IntroductionThis study aimed to evaluate the status of dietary diversity, nutrient adequacy, blood biomarkers of nutrients, and anthropometric status, as well as to determine the predictors of dietary diversity score (DDS) and mean adequacy ratio (MAR) among preschool children in poor ethnic minority areas of northwest China.MethodsA total of 578 healthy preschool children aged 3–6 from 17 kindergartens were selected to assess dietary intake, anthropometric status (height-for-age z-score (HAZ), weight-for-age z-score (WAZ), weight-for-height z-score (WHZ), and blood biomarkers. DDS and nutrient adequacy ratio (NAR) were adopted to assess dietary diversity and micronutrient adequacy, respectively.ResultsThe mean DDS (ranging from 1 to 9) was relatively low (4.67 ± 1.56). Most participants consumed starchy staples, but few participants consumed organ meat. DDS was associated with serum potassium, serum iron, WAZ, HAZ, all NARs, and MAR (all p < 0.05). Living in urban areas (β = 0.158), higher household wealth (β = 0.116), and more caregivers’ nutritional knowledge (β = 0.022) were positively associated with DDS (all p < 0.01), while living in urban areas (β = 0.031), higher education of caregivers (β = 0.0.027), and higher DDS (β = 0.049) were positively associated with MAR (all p < 0.01).DiscussionIn conclusion, dietary diversity was associated with nutrient adequacy and other health outcomes. Nutritional education and poverty alleviation are integral to improving the nutritional status of preschool children.

Zinc deficiency could lead to a dynamic variation in gut microbial composition and function in animals. However, how zinc deficiency affects the gut microbiome in school-age children remains unclear. The purpose of this study was to profile the dynamic shifts in the gut microbiome of school-age children with zinc deficiency, and to determine whether such shifts are associated with dietary intake. A dietary survey, anthropometric measurements, and serum tests were performed on 177 school-age children, and 67 children were selected to explore the gut microbial community using amplicon sequencing. School-age children suffered from poor dietary diversity and insufficient food and nutrient intake, and 32% of them were zinc deficient. The inflammatory cytokines significantly increased in the zinc deficiency (ZD) group compared to that in the control (CK) group (p < 0.05). There was no difference in beta diversity, while the Shannon index was much higher in the ZD group (p < 0.05). At the genus level, Coprobacter, Acetivibrio, Paraprevotella, and Clostridium_XI were more abundant in the ZD group (p < 0.05). A functional predictive analysis showed that the metabolism of xenobiotics by cytochrome P450 was significantly depleted in the ZD group (p < 0.05). In conclusion, gut microbial diversity was affected by zinc deficiency with some specific bacteria highlighted in the ZD group, which may be used as biomarkers for further clinical diagnosis of zinc deficiency.

This study aimed to evaluate the status of dietary diversity and nutrient intake among Han and Dongxiang smallholder farmers in poor rural areas of northwest China. In this cross-sectional study, dietary intake was assessed in 499 smallholder farmers aged 18–75 years from two nationally designated impoverished counties in Gansu Province, China, using three consecutive 24 h dietary recalls. The dietary diversity score (DDS) and nutrient adequacy ratio (NAR) were adopted to assess dietary diversity and micronutrient adequacy, respectively. The mean DDS (range from 1 to 9) in participants was relatively low (3.81 ± 1.01). Consumption of grains was excessive, while consumption of vegetables, fruits, meat, beans, eggs, fish, and dairy was inadequate. The NAR values were higher in Han Chinese, with the exceptions of vitamin C, potassium, pyridoxine, and selenium (p < 0.05). For each nutrient, the high DDS group had a higher mean NAR (p < 0.05), except for pyridoxine. High household monthly income, being Han Chinese, high DDS, and being aged over 45 years were positively associated with mean adequacy ratio (MAR) of 14 micronutrients evaluated. Lack of dietary diversity and insufficient intake of essential micronutrients are public health concerns in northwest China. Nutrition education and other proper methods to address these issues are needed.

We have previously shown that following oral administration of myelin basic protein (MBP), regulatory T cells are generated from gut-associated lymphoid tissue and that these cells suppress experimental allergic encephalomyelitis (EAE). These regulatory T cells produce transforming growth factor-beta (TGF-beta) with various amounts of IL-4 and IL-10 and these TGF-beta-secreting T cells have been termed Th3 cells. T cells in lymphoid organs drained by mucosal sites secrete IL-4 as a primary T cell growth factor. In the present study, we examined the role of IL-4 on oral tolerance and in the generation of TGF-beta secreting cells. Treatment of (PLJ x SJL)FI mice with intraperitoneal (i.p.) IL-4 and low-dose oral MBP (0.5 mg) given three times reduced the severity of EAE, whereas i.p. injection of IL-4 alone or oral MBP alone given in these suboptimal doses, showed no protection. Spleen cells from protected mice produced increased amounts of TGF-beta and reduced IFN-gamma upon stimulation with MBP in vitro. Mucosal MBP-specific IgA production was significantly increased in IL-4 plus MBP fed animals. Moreover, oral administration of IL-4 (1 mu g per feeding) also enhanced the suppression of EAE by oral MBP and this protective effect was reversed by administration of anti-TGF-beta antibody in vivo. Reverse transcription-PCR showed enhanced suppression of IFN-gamma in Peyer's patch in animals fed MBP and IL-4 versus those fed MBP alone. We then investigated the role of IL-4 in the generation of TGF-beta-secreting cells using MBP Ac1-11 TCR transgenic animals. Cells were cultured with IL-2, IL-4, or IFN-gamma in the presence of MBP and limiting dilution analysis for cytokine-secreting cells performed. We found that IL-4, but not IL-2 or IFN-gamma, generated TGF-beta-secreting T cells from naive splenic T cells and that these cells provided help for IgA production. These findings demonstrate that IL-4 is a differentiation factor for TGF-beta-secreting Th3 cells and oral IL-4 has a synergistic effect on low-dose oral tolerance that is associated with increased TGF-beta secretion.

ORAL administration of antigen is used to induce antigen-specific peripheral immune tolerance(1,2). As well as preventing systemic immune responses to ingested proteins(3), oral tolerance to autoantigens has also been used to suppress autoimmune diseases in animals(4-10) and humans(11,12). Both active suppression and clonal anergy are suggested to be mechanisms of oral tolerance, depending on the dose of antigen fed(13,14). Here we report that oral antigen can delete antigen-reactive T cells in Peyer's patches, in mice transgenic for the ovalbumin-specific T-cell receptor genes, The deletion was mediated by apoptosis, and was dependent on dosage and frequency of feeding. At lower doses deletion was not observed; instead there was induction of antigen-specific cells that produced transforming growth factor (TGF)beta and interleukin (IL)-4 and IL-10 cytokines. At higher doses, both Th1 and Th2 cells were deleted following their initial activation, whereas cells which secrete TGF-beta were resistant to deletion. These findings demonstrate that orally administered antigen can induce tolerance not only by active suppression and clonal anergy