The First 1000 Days of Life: How Changes in the Microbiota Can Influence Food Allergy Onset in Children

Abstract

Background: Allergic disease, including food allergies (FA)s, has been identified as a major global disease. The first 1000 days of life can be a “window of opportunity” or a “window of susceptibility”, during which several factors can predispose children to FA development. Changes in the composition of the gut microbiota from pregnancy to infancy may play a pivotal role in this regard: some bacterial genera, such as Lactobacillus and Bifidobacterium, seem to be protective against FA development. On the contrary, Clostridium and Staphylococcus appear to be unprotective. Methods: We conducted research on the most recent literature (2013–2023) using the PubMed and Scopus databases. We included original papers, clinical trials, meta-analyses, and reviews in English. Case reports, series, and letters were excluded. Results: During pregnancy, the maternal diet can play a fundamental role in influencing the gut microbiota composition of newborns. After birth, human milk can promote the development of protective microbial species via human milk oligosaccharides (HMOs), which play a prebiotic role. Moreover, complementary feeding can modify the gut microbiota’s composition. Conclusions: The first two years of life are a critical period, during which several factors can increase the risk of FA development in genetically predisposed children.

Antimicrobial Stewardship: A Correct Management to Reduce Sepsis in NICU Settings

“…At 2–4 years of age, adult-like microbiota occurs, with a relative abundance of Bacteroidota and Firmicutes [ 14 ]. Many factors can influence the composition of children’s gut microbiota and among these is antibiotic exposure early in life [ 32 ]. The massive use of broad-spectrum antibiotics can alter and modify microbiota composition and maturation by eradicating beneficial microbes and reducing the diversity of bacterial species and strains, with a consequent “dysbiosis” phenomenon [ 32 , 33 ].…”

“…Many factors can influence the composition of children’s gut microbiota and among these is antibiotic exposure early in life [ 32 ]. The massive use of broad-spectrum antibiotics can alter and modify microbiota composition and maturation by eradicating beneficial microbes and reducing the diversity of bacterial species and strains, with a consequent “dysbiosis” phenomenon [ 32 , 33 ]. Infants who receive antibiotic therapy in the first phases of life have difficulty in regaining typical commensal microbiota even after breastfeeding; maybe, this is due to a change in the natural developmental trajectory of gut microbiota [ 34 ].…”

“…Changes in newborns’ microbiota have been also described in children whose mothers underwent antibiotic therapy during pregnancy: maternal antibiotic exposure is associated with a reduction in Prevotella copri , the predominant Prevotella spp. within the human gut [ 32 ]. At the same time, antibiotic use during pregnancy has been associated with a reduction in Bifidobacteria count and, as demonstrated in a study conducted by Zou et al [ 40 ], with an increase in resistant bacteria in a NICU setting [ 14 ].…”

Comparative analysis of pectin and prebiotics on human microbiota modulation in early life stages and adults

“…3 The term “microbiome” refers to the collective genetic material of these microorganisms. 4 The gut microbiota is vastly diverse, including approximately 1000 species of bacteria, 5 genera of Archae, 66 genera of fungi, and several viruses, mostly bacteriophages. 5 The sheer diversity of microorganisms inhabiting the human body is high, with estimates of around 1150 different species, and each person typically hosts approximately 160 distinct bacterial species.…”

“…24 This dysbiosis increases intestinal permeability, exacerbating the inflammatory response and creating a vicious cycle that further disrupts the gut microbial community. 4 In obesity, for example, a high-fat diet can induce alterations in the gut microbiota, leading to increased intestinal permeability and decreased production of SCFA. 24 This “obese microbiota” can further influence the nervous system by affecting the expression of genes in the hypothalamus and promoting overeating.…”