Metabolome and microbiome alterations related to short-term feeding of a micronutrient-fortified, high-quality legume protein-based food product to stunted school age children: A randomized controlled pilot trial

Abstract

Background & aims: Stunting in children is a comorbid condition in undernutrition that may be ameliorated by the provision of high-quality foods that provide protein and micronutrients. Addressing this problem in lower social economic environments requires, in part, affordable and scalable food-based solutions with efficacious food products. Towards this end, biochemical/metabolic indicators for fast-throughput screening of foods and their components are desired. A highly acceptable and economical micronutrient-fortified food product with different levels of legume protein was provided to stunted Indian children for one month, to determine change in their linear growth and explore associated biochemical, metabolomic and microbiome indicators.

Methods: A randomized controlled pilot trial was conducted with 100 stunted children (6-10 years of age) to elucidate metabolic and microbiome-based biomarkers associated with linear growth. They were randomized into 4 groups receiving 6, 8, 10 or 12 g of legume-based protein for one month. Anthropometry, blood biochemistry, aminoacidomics, acylcarnitomics and fecal microbiome were measured before and after feeding.

Results: No significant differences were observed between groups in height, height-for-age Z-score (HAZ) or BMI-for-age Z-score (BAZ); however, 38 serum metabolites were altered significantly (Bonferroni adjusted P < 0.1) in response to the interventions. IGF-1 (Insulin like Growth Factor-1) was positively (ρ > 0.2, P = 0.02), while serine and ornithine (ρ < -0.2, P = 0.08) were negatively associated with change in height. Leucine, isoleucine and valine positively correlated (P = 0.011, 0.023 and 0.007 respectively) with change in BAZ. Three Operational Taxonomic Units belonging to Bacteroidetes and Firmicutes (VIP score > 1.5) were significantly correlated with change in height.

Conclusions: In this pilot trial, a number of fasting serum metabolomic and fecal microbiome signatures were associated with linear growth after a short-term dietary intervention. The alterations of these markers should be validated in long-term dietary intervention trials as potential screening indicators towards the development of food products that favor growth. This trial was registered at www.ctri.nic.in as CTRI/2016/12/007564.

Keywords: Intervention; Legume protein; Linear growth; Metabolome; Microbiome; Stunting.

Fig. 1. Trial flow diagram for the doseeresponse intervention study.

Fig. 2

Spearman rank correlation of change in metabolites with change in anthropometric measures. CRP: C-reactive protein, hGH: human growth hormone, IGF: insulin-like growth factor 1, IL-6: interleukin-6. Statistical significance with Bonferroni adjusted P value < 0.1 indicated with *.

Fig. 3. VIP score (>1.5) of metabolite fold change in PLS-R with height change and the Spearman rank correlation coefficients.

Fig. 4. VIP score of fold change of relative % abundance of OTUs in PLS-R (VIP score >1.5) with height change and the Spearman rank correlation coefficient.