Gut microbiota in Malawian infants in a nutritional supplementation trial

ObjectivesTo examine whether two forms of lipid-based nutrient supplements (LNS) or a micronutrient-fortified corn-soya blend were associated with development of the gut microbiota in Malawian infants, to assess the microbiota profiles at the age of 6 and 18 months and to follow the changes during the 12-month period. MethodsThis was a substudy of a 4-arm randomised controlled trial conducted in rural Malawi. Infants at the age of 6 months were randomised to receive no supplement during the primary follow-up period (control), 54 g/day of micronutrient-fortified LNS with milk protein base (milk LNS), 54 g/day of micronutrient-fortified LNS with soya protein base (soya LNS), or 71 g/day of micronutrient-fortified corn-soya blend for 12 months. Stool samples were collected at baseline (6 months) and end of trial (18 months). The 16S rRNA gene was amplified and subjected to multiplex sequencing. ResultsA total of 213 infants had paired microbiota data at 6 and 18 months of age. The Dirichlet-multinomial test showed no significant difference in microbiota profile between the four intervention groups at either age (each P > 0.10). Bifidobacterium longum was most abundant at both ages. Lactobacillus ruminis, Shigella and Salmonella were present. The abundance of Prevotella and Faecalibacterium increased with age (each P < 0.001), while Bifidobacteriaceae and Enterobacteriaceae exhibited significant decrease (each P < 0.001). ConclusionsNutritional supplementation by LNS or corn-soya blend for twelve months did not affect the gut microbiota profile in the rural Malawian context.