The association between immunity and metabolic syndrome (MetS) has been studied, but its interaction with lifestyles remains unclear. We studied their association and interactions with lifestyles in 40,768 adults aged over 40 years from a large-scale, hospital-based cohort study collected during 2010–2013. White blood cell counts (WBC) and serum C-reactive protein concentrations (CRP) were used as indexes of immune status. The participants were categorized into four groups by the cutoff points of 6.2 × 10⁹/L WBC(L-WBC) and <0.5 mg/dL CRP(L-CRP): L-WBC+L-CRP(n = 25,604), H-WBC+L-CRP(n = 13,880), L-WBC+H-CRP(n = 464), and H-WBC+H-CRP(n = 820). The participants in the H-WBC+L-CRP were younger and had higher numbers of males than the L-WBC+L-CRP. MetS risk was higher by 1.75- and 1.86-fold in the H-WBC+L-CRP and H-WBC+H-CRP, respectively, than the L-WBC+L-CRP. MetS components, including plasma glucose and triglyceride concentrations, and SBP were elevated in H-WBC+L-CRP and H-WBC+H-CRP compared with L-WBC+L-CR+P. The risk of hyperglycemia and high HbA1c was the highest in the H-WBC+H-CRP among all groups. Areas of WBC counts and serum CRP concentrations were 0.637 and 0.672, respectively, in the receiver operating characteristic curve. Daily intake of energy, carbohydrate, protein, and fat was not significantly different in the groups based on WBC counts and CRP. However, a plant-based diet (PBD), physical activity, and non-smoking were related to lowering WBC counts and CRP, but a Western-style diet was linked to elevating CRP. A high PBD intake and smoking status interacted with immunity to influence MetS risk: a low PBD and current smoking were associated with a higher MetS risk in the H-WBC+H-CRP. In conclusion, overactivated immunity determined by CRP and WBC was associated with MetS risk. Behavior modification with PBD and physical activity might be related to immunity regulation. Full article

The etiology of multifactorial morbidities such as undernutrition and anemia in children living with the human immunodeficiency virus (HIV) (HIV+) on antiretroviral therapy (ART) is poorly understood. Our objective was to examine associations of HIV and iron status with nutritional and inflammatory status, anemia, and dietary intake in school-aged South African children. Using a two-way factorial case-control design, we compared four groups of 8 to 13-year-old South African schoolchildren: (1) HIV+ and low iron stores (inflammation-unadjusted serum ferritin ≤ 40 µg/L), n = 43; (2) HIV+ and iron sufficient non-anemic (inflammation-unadjusted serum ferritin > 40 µg/L, hemoglobin ≥ 115 g/L), n = 41; (3) children without HIV (HIV-ve) and low iron stores, n = 45; and (4) HIV-ve and iron sufficient non-anemic, n = 45. We assessed height, weight, plasma ferritin (PF), soluble transferrin receptor (sTfR), plasma retinol-binding protein, plasma zinc, C-reactive protein (CRP), α-1-acid glycoprotein (AGP), hemoglobin, mean corpuscular volume, and selected nutrient intakes. Both HIV and low iron stores were associated with lower height-for-age Z-scores (HAZ, p < 0.001 and p = 0.02, respectively), while both HIV and sufficient iron stores were associated with significantly higher CRP and AGP concentrations. HIV+ children with low iron stores had significantly lower HAZ, significantly higher sTfR concentrations, and significantly higher prevalence of subclinical inflammation (CRP 0.05 to 4.99 mg/L) (54%) than both HIV-ve groups. HIV was associated with 2.5-fold higher odds of iron deficient erythropoiesis (sTfR > 8.3 mg/L) (95% CI: 1.03–5.8, p = 0.04), 2.7-fold higher odds of subclinical inflammation (95% CI: 1.4–5.3, p = 0.004), and 12-fold higher odds of macrocytosis (95% CI: 6–27, p < 0.001). Compared to HIV-ve counterparts, HIV+ children reported significantly lower daily intake of animal protein, muscle protein, heme iron, calcium, riboflavin, and vitamin B₁₂, and significantly higher proportions of HIV+ children did not meet vitamin A and fiber requirements. Compared to iron sufficient non-anemic counterparts, children with low iron stores reported significantly higher daily intake of plant protein, lower daily intake of vitamin A, and lower proportions of inadequate fiber intake. Along with best treatment practices for HIV, optimizing dietary intake in HIV+ children could improve nutritional status and anemia in this vulnerable population. This study was registered at clinicaltrials.gov as NCT03572010. Full article

Gastrointestinal symptoms in Crohn’s disease (CD) are common and affect the quality of life of patients; consequently, a growing number of studies have been published on diet interventions in this group. The role of the gut microbiota in the pathogenesis and the progression of inflammatory bowel diseases (IBD), including CD, has been widely discussed. Mainly, a decreased abundance of Firmicutes, species of the Bifidobacterium genus, and the Faecalibacterium prausnitzii species as well as a reduced general diversity have been described. In this review article, we summarize available data on the influence of reduction diets on the microbiome of patients with CD. One of the most frequently used elimination diets in CD patients is the low-FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) diet. Although many papers show it may reduce abdominal pain, diarrhea, or bloating, it also reduces the intake of prebiotic substances, which can negatively affect the gut microbiota composition, decreasing the abundance of Bifidobacterium species and Faecalibacterium prausnitzii. Other elimination diets used by IBD patients, such as lactose-free or gluten-free diets, have also been shown to disturb the microbial diversity. On the other hand, CDED (Crohn’s disease exclusion diet) with partial enteral nutrition not only induces the remission of CD but also has a positive influence on the microbiota. The impact of diet interventions on the microbiota and, potentially, on the future course of the disease should be considered when nutritional guidelines for IBD patients are designed. Dietetic recommendations should be based not only on the regulation of the symptoms but also on the long-term development of the disease. Full article

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. Although the precise etiology of IBD is largely unknown, it is widely thought that diet contributes to the development of IBD. Diet shapes the composition of the gut microbiota, which plays critical roles in intestinal homeostasis. In contrast, intestinal inflammation induces gut dysbiosis and may affect the use of dietary nutrients by host cells and the gut microbiota. The interaction of diet and the gut microbiota is perturbed in patients with IBD. Herein, we review the current knowledge of diet and gut microbiota interaction in intestinal homeostasis. We also discuss alterations of diet and gut microbiota interaction that influence the outcome and the nutritional treatment of IBD. Understanding the complex relationships between diet and the gut microbiota provides crucial insight into the pathogenesis of IBD and advances the development of new therapeutic approaches. Full article

Viral infections have been a cause of mortality for several centuries and continue to endanger the lives of many, specifically of the younger population. Vitamin D has long been recognized as a crucial element to the skeletal system in the human body. Recent evidence has indicated that vitamin D also plays an essential role in the immune response against viral infections and suggested that vitamin D deficiency increases susceptibility to viral infections as well as the risk of recurrent infections. For instance, low serum vitamin D levels were linked to increased occurrence of high burdens viral diseases such as hepatitis, influenza, Covid-19, and AIDS. As immune cells in infected patients are responsive to the ameliorative effects of vitamin D, the beneficial effects of supplementing vitamin D-deficient individuals with an infectious disease may extend beyond the impact on bone and calcium homeostasis. Even though numerous studies have highlighted the effect of vitamin D on the immune cells, vitamin D’s antiviral mechanism has not been fully established. This paper reviews the recent mechanisms by which vitamin D regulates the immune system, both innate and adaptive systems, and reflects on the link between serum vitamin D levels and viral infections. Full article

The efficacy of diet and its influence on gut microbiome composition has been largely demonstrated in inflammatory bowel disease (IBD). Little is known about its potential in the management of extraintestinal manifestations. We report a successful application of Crohn disease exclusion diet (CDED) in association with infliximab and methotrexate, as salvage therapy in a child affected by chronic recurrent multifocal osteomyelitis (CRMO) and Crohn disease (CD) resistant to optimized therapy. Both intestinal and bone symptoms remitted after the application of CDED. Diet may have acted on common microbic inciting agents that trigger both intestinal and bone inflammation, supporting the role of microbiota in the pathogenesis of IBD-associated extraintestinal manifestations. Our experience suggests the potential benefit of CDED in association with combined therapy in resistant patients affected by CD and extraintestinal manifestations. Full article