The gut microbiome and childhood growth: implications for microbiota-directed interventions

Abstract

Healthy childhood growth depends on complex interactions between nutrition, metabolism, immune function and the intestinal environment during the first 1 000 days of life. Increasing evidence indicates that the gut microbiome is an active contributor to these processes, providing a biological link between early-life nutrition and growth. While undernutrition has traditionally been attributed to inadequate dietary intake and recurrent infections, disruption of normal gut microbiome development is now recognised as an important factor contributing to growth faltering. Dysbiosis may impair nutrient utilisation, compromise intestinal barrier function, alter immune and endocrine signalling, and contribute to environmental enteric dysfunction (EED), thereby limiting the effectiveness of conventional nutritional rehabilitation. This review synthesises current evidence on the role of the gut microbiome in childhood growth, with particular emphasis on microbiota-directed nutritional interventions during the first 1 000 days of life. The review describes the normal development and metabolic functions of the infant gut microbiome, examines the mechanisms through which dysbiosis contributes to impaired growth, and evaluates established and emerging nutritional strategies that influence the developing microbiome. Breastfeeding and appropriate complementary feeding remain the cornerstone of healthy infant nutrition and are increasingly recognised as the first microbiota-directed nutritional intervention. More recently, microbiota-directed complementary foods have shown promising effects on microbial maturation, restoration of microbial metabolic function and improvements in child growth. By contrast, although prebiotics, probiotics and synbiotics can beneficially modify the gut microbiome, current evidence supporting consistent improvements in childhood growth remains limited. Advances in microbiome research provide a stronger biological basis for established infant and young child feeding recommendations while identifying new opportunities to optimise nutritional rehabilitation. Although microbiota-directed complementary foods represent a promising development, further evidence from well-designed clinical trials conducted in diverse populations is required before these interventions can be incorporated into routine clinical practice. For dietitians and other clinicians, microbiome science provides a biological framework that strengthens and refines evidence-based nutritional strategies to support healthy childhood growth.

Keywords: gut microbiome, childhood growth, microbiota-directed complementary foods, breastfeeding, complementary feeding, undernutrition