In recent years, the number of scientific publications on the role of intestinal microbiota in shaping human health, as well as the occurrence of intestinal dysbiosis in various disease entities, has increased dynamically. However, there is a gap in comprehensively understanding the factors influencing a child’s gut microbiota. This review discusses the establishment of gut microbiota and the immunological mechanisms regulating children’s microbiota, emphasising the importance of prioritising the development of appropriate gut microbiota in a child from the planning stages of pregnancy. The databases PubMed, Web of Sciences, Cochrane, Scopus and Google Scholar were searched to identify relevant articles. A child’s gut microbiota composition is influenced by numerous factors, such as diet during pregnancy, antibiotic therapy, the mother’s vaginal microbiota, delivery method, and, later, feeding method and environmental factors. During pregnancy, the foetus naturally acquires bacterial strains from the mother through the placenta, thereby shaping the newborn’s immune system. Inappropriate maternal vaginal microbiota may increase the risk of preterm birth. Formula-fed infants typically exhibit a more diverse microbiota than their breastfed counterparts. These factors, among others, shape the maturation of the child’s immune system, impacting the production of IgA antibodies that are central to cellular humoral immune defence. Further research should focus on identifying specific microbiota–immune system interactions influencing a child’s immune health and developing personalised treatment strategies for immune-related disorders.

Folic acid might improve endothelial function, but the results are inconclusive. This systematic review evaluated the effect of folic acid supplementation on endothelial parameters and arterial stiffness in adults. The study protocol was registered with the PROSPERO database (CRD42021290195). The PubMed, Web of Sciences, Cochrane and Scopus databases were searched to identify English-language randomised controlled trials of the effect of folate supplementation on arterial stiffness and endothelial function markers in adults. There were significant differences between the effect of folic acid and placebo on flow-mediated dilation (random-effects model, standardized mean differences (SMD): 0.888, 95% confidence interval (CI): 0.447, 1.329, p < 0.001) and monocyte chemotactic protein 1 (random-effects model, SMD: −1.364, 95% CI: −2.164, −0.563, p < 0.001), but there was no significant difference in the central pulse wave velocity (fixed-effects model, SMD: −0.069, 95% CI: −0.264, 0.125, p = 0.485) and peripheral pulse wave velocity (fixed-effects model, SMD: −0.093, 95% CI: −0.263, 0.077, p = 0.284). In conclusion, folic acid might have a favourable effect on endothelial function but may not affect arterial stiffness. Further studies are needed to confirm these results.

The PA Protect study investigated the impact of increased daily physical activity on preventing cognitive decline, and maintaining healthy biomarker levels in individuals with mild cognitive impairment. Participants aged 50-70 years, selected based on their performance in the Montreal Cognitive Assessment test were enrolled in a double-blind randomized controlled trial and randomly assigned to either an active or passive group. The active group was instructed to achieve over 10,000 daily steps, while the passive group maintained usual activity levels. Preliminary findings revealed a positive influence of increased physical activity on cognitive function, with significant differences observed between the two groups in selected cognitive tests. Building on these results, this study extends the PA Protect trial for an additional three years. All participants will undergo cognitive assessments and biomarker analyses at the beginning and after the extended intervention period, providing further insights into long-term intervention effects.