Evaluating the Alimentary and Respiratory Tracts in Health and disease (EARTH) research programme: a protocol for prospective, longitudinal, controlled, observational studies in children with chronic disease at an Australian tertiary paediatric hospital.

INTRODUCTION: Chronic gastrointestinal and respiratory conditions of childhood can have long-lasting physical, psychosocial and economic effects on children and their families. Alterations in diet and intestinal and respiratory microbiomes may have important implications for physical and psychosocial health. Diet influences the intestinal microbiome and should be considered when exploring disease-specific alterations. The concepts of gut-brain and gut-lung axes provide novel perspectives for examining chronic childhood disease(s). We established the 'Evaluating the Alimentary and Respiratory Tracts in Health and disease' (EARTH) research programme to provide a structured, holistic evaluation of children with chronic gastrointestinal and/or respiratory conditions. METHODS AND ANALYSIS: The EARTH programme provides a framework for a series of prospective, longitudinal, controlled, observational studies (comprised of individual substudies), conducted at an Australian tertiary paediatric hospital (the methodology is applicable to other settings). Children with a chronic gastrointestinal and/or respiratory condition will be compared with age and gender matched healthy controls (HC) across a 12-month period. The following will be collected at baseline, 6 and 12 months: (i) stool, (ii) oropharyngeal swab/sputum, (iii) semi-quantitative food frequency questionnaire, (iv) details of disease symptomatology, (v) health-related quality of life and (vi) psychosocial factors. Data on the intestinal and respiratory microbiomes and diet will be compared between children with a condition and HC. Correlations between dietary intake (energy, macro-nutrients and micro-nutrients), intestinal and respiratory microbiomes within each group will be explored. Data on disease symptomatology, quality of life and psychosocial factors will be compared between condition and HC cohorts.Results will be hypothesis-generating and direct future focussed studies. There is future potential for direct translation into clinical care, as diet is a highly modifiable factor. ETHICS AND DISSEMINATION: Ethics approval: Sydney Children's Hospitals Network Human Research Ethics Committee (HREC/18/SCHN/26). Results will be presented at international conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04071314.

Advancing nutritional therapy: A novel polymeric formulation attenuates intestinal inflammation in a murine colitis model and suppresses pro-inflammatory cytokine production in ex-vivo cultured inflamed colonic biopsies.

BACKGROUND & AIMS: Nutritional therapy is a viable therapeutic option for the treatment of Crohn disease (CD). Therefore improving nutritional therapy would greatly benefit CD patients. The aim of this study was to define the anti-inflammatory properties of a novel nutritional polymeric formula (PF) in comparison to a currently available standard PF. METHODS: Dextran sodium sulfate (DSS) was utilized to induce colitis in C57BL/6 mice with mice randomized to receive either standard PF or novel PF in addition to control groups. Changes in body weight were recorded and colonic damage was assessed histologically and biochemically. Additional experiments were also included where the cytokine response of colonic biopsies from pediatric CD patients was measured following exposure to standard PF or novel PF. RESULTS: DSS induced significant body weight loss, morphological changes in the colon, increased myeloperoxidase (MPO) activity and up-regulated colonic mRNA expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-12 and monocyte chemoattractant protein (MCP)-1, as well as associated histological changes. Other than histological damage, these inflammatory changes were reversed by both novel and standard PF. However, the novel PF, but not standard PF, completely suppressed TNF-α, IL-6 and IL-8 levels from cultured biopsies. CONCLUSIONS: Newly developed nutritional formula reproducibly ameliorated DSS-induced colitis in a murine model, although this response was not measurably different to standard PF. However, the novel PF was significantly superior in suppressing inflammatory cytokine release from cultured colonic biopsies. Collectively, these findings support a possible role for novel PF in advancing nutritional therapy for CD patients.

Are children on jejunal feeds at risk of iron deficiency?

Children on exclusive jejunal feeding may be at risk of iron deficiency due to the feeds bypassing the duodenum, which is the primary site for iron absorption. We describe the biochemical and hematological features of six children on exclusive jejunal feeding who did not receive iron supplementation. At a mean (standard deviation) period of 11 (6.5) mo after commencing jejunal feeds, there was a significant reduction in both serum iron (18.5 g/L vs 9.8 g/L, P = 0.01) and transferrin saturation levels (23.1% vs 13.7%, P = 0.02), suggesting iron deficiency. However, there was no significant change in ferritin, hemoglobin and mean corpuscular volume levels post-commencement of jejunal feeds. This may be the result of small bowel adaptation in response to early iron deficiency. Larger and longer term prospective studies are required to investigate if children on jejunal feeds are at risk of developing iron deficiency.