Recently, the immune system has been identified as one of the possible main bridges which connect the gut–brain axis. This review aims to examine available evidence on the microbiota–immunity–cognitive relationship and its possible effects on human health early in life. This review was assembled by compiling and analyzing various literature and publications that document the gut microbiota–immune system–cognition interaction and its implications in the pediatric population. This review shows that the gut microbiota is a pivotal component of gut physiology, with its development being influenced by a variety of factors and, in return, supports the development of overall health. Findings from current research focus on the complex relationship between the central nervous system, gut (along with gut microbiota), and immune cells, highlighting the importance of maintaining a balanced interaction among these systems for preserving homeostasis, and demonstrating the influence of gut microbes on neurogenesis, myelin formation, the potential for dysbiosis, and alterations in immune and cognitive functions. While limited, evidence shows how gut microbiota affects innate and adaptive immunity as well as cognition (through HPA axis, metabolites, vagal nerve, neurotransmitter, and myelination).

Prebiotics have long been known to play an important role in supporting the immune system, especially in children. However, recent research shows that the benefits of prebiotics are not limited to increasing immunity. Prebiotics also have a positive impact on children's physical and cognitive growth. This study aims to identify and analyze the benefits of prebiotics on children's physical growth and cognitive development. This study uses a qualitative research method. The data collection technique in this study was through literature studies. The data that has been collected was then analyzed in three stages, namely data reduction, data presentation and drawing conclusions. Research shows that prebiotics play a role in supporting children's physical growth by improving nutrient absorption and supporting healthy bone development. In addition, prebiotics also have an important role in improving cognitive function. The relationship between gut health and the brain is increasingly recognized, with recent research stating that the condition of the gut microbiota can affect cognitive health. Beneficial bacteria that receive prebiotic intake can produce compounds that can cross the blood-brain barrier, affecting cognitive functions such as memory, learning, and concentration.

Disorders of gut health can impact a variety of health problems, including the digestive system, immunity, and even mental health. The aim of this study was to investigate the potential of probiotics and synbiotics as potential biotics in nutrition to improve gut health. This study used qualitative research methods. The data collection technique for this is literature study. The data that has been collected is then analyzed in three stages, namely data reduction, data presentation and drawing conclusions. The research results show that probiotics and synbiotics are potential biotics in nutrition that can improve intestinal health. Probiotics and synbiotics can help modulate the composition of the body's beneficial microbiota. In addition, it can help reduce levels of pathogenic bacteria and help reduce persistent inflation of the intestines, which can improve the balance of the body's beneficial microbiota