# Gut microbial diversity impacts carbohydrate fermentation by children with severe acute malnutrition

## TL;DR

Children with severe malnutrition have gut microbes that poorly ferment inulin, but this improves over time with treatment.

## Contribution

Shows that children with SAM initially lack inulin fermentation ability due to low microbial diversity, but this improves with recovery.

## Key findings

- Children with SAM cannot ferment inulin ex vivo due to low microbial diversity and high Proteobacteria.
- After recovery, microbial diversity increases and inulin fermentation ability improves.
- Alternative carbohydrates may be more effective than inulin in early treatment of SAM.

## Abstract

African children suffering from severe acute malnutrition (SAM) have a disrupted gut microbiome and low short-chain fatty acids (SCFAs). These are linked to persistently high mortality and morbidity rates. Supplementing recovery feeding regimes with suitable fermentable carbohydrate may improve outcomes in SAM. We adapted in vitro colon models to investigate the ability of children with SAM to utilize four carbohydrate substrates: milk powders (with and without human milk-like oligosaccharides), chickpea-enriched feed, and inulin. All substrates, except inulin, were fermented to produce SCFAs. The inability to utilize inulin ex vivo, a widely used prebiotic, is attributed to low microbial diversity, enriched with Proteobacteria. Stool samples obtained after partial anthropometric recovery showed increased microbial diversity and higher levels of GH32 enzyme family, responsible for inulin metabolism. These findings can inform the design of future therapeutic feeds for the treatment of SAM, where inulin has been found ineffective during initial hospitalization. Alternative carbohydrates appear to be more effective in supporting gut recovery during both the initial and later treatment phases.

•Children with SAM have high fecal Proteobacteria, especially Escherichia-Shigella•7 days post-hospitalization, they cannot effectively utilize inulin ex vivo•By 90 days post-care, Firmicutes increases and Proteobacteria decreases•At 90 days, GH32 enzyme family levels rise, enabling inulin utilization and SCFA production

Children with SAM have high fecal Proteobacteria, especially Escherichia-Shigella

7 days post-hospitalization, they cannot effectively utilize inulin ex vivo

By 90 days post-care, Firmicutes increases and Proteobacteria decreases

At 90 days, GH32 enzyme family levels rise, enabling inulin utilization and SCFA production

Microbiology; Microbiome; Pediatrics