Sexual differences of gut microbiome in infants and its clinical significance

BACKGROUND: Numerous studies of the intestinal microbiome have shown its role in pathogenesis of diseases in children. However, the role of such a factor as the child’s gender is little taken into account in these studies. AIM: The purpose of this study to identify the features of the intestinal microbiome composition of children aged 1 month, born vaginally and breastfed, depending on the child’s gender. MATERIALS AND METHODS: the study included 103 children aged 4–6 weeks of life (group 1 — 46 girls, group 2 — 57 boys), examined at Professor Bushtyreva’s Clinic LLC from 2019 to 2020, each of whom underwent stool sampling for further sequencing of 16S rRNA. RESULTS: Results of 16s rRNA sequencing revealed that the proportion of Erysipelatoclostridium bacteria, that predispose to the development of allergic reactions and inflammatory bowel diseases, was significantly higher in boys than in girls (12.52 and 0.2% respectively, p = 0.020). The proportion of Lachnoclostridium bacteria, high amounts of which are associated with resistance to diseases of the nervous system, also differed significantly in the groups of boys and girls (0.01 and 5.78% respectively, p = 0.046). Analysis of correlation matrices revealed that the correlation adaptometry coefficient in the group of boys was almost 4 times higher than in girls (9.5 and 2.4 respectively). Analysis of morbidity in children under one year old revealed that allergies were almost 3 times more common in boys than in girls (33.3 and 13%). Episodes of acute intestinal infections in the first year of life were registered in 6 boys and only in 1 girl (10.5 and 2.2%). CONCLUSIONS: In boys at 1st month of life, born vaginally and breastfed, compared to girls, the proportion of bacteria of the genus Erysipelatoclostridium in the intestinal microbiome is higher, that is a risk factor for the development of allergic reactions and inflammatory bowel diseases. At the same time, the proportion of bacteria of the genus Lachnoclostridium, on the contrary, was 5 times higher in girls than in boys. The revealed differences can be used to select preventive probiotic therapy taking into account the child’s gender.