ABSTRACTIntroductionThe metabolic activity of the gut microbiota plays a pivotal role in the gut-brain axis through the effects of bacterial metabolites on brain function and development. In this study we investigated the association of gut microbiota composition with language development of three-year-old rural Ugandan children.MethodsWe studied the language ability in 139 children of 36 months in our controlled maternal education intervention trial to stimulate children’s growth and development. The dataset includes 1170 potential predictors, including anthropometric and cognitive parameters at 24 months, 542 composition parameters of the children’s gut microbiota at 24 months and 621 of these parameters at 36 months. We applied a novel computationally efficient version of the all-subsets regression methodology and identified predictors of language ability of 36-months-old children scored according to the Bayley Scales of Infant and Toddler Development (BSID-III).ResultsThe best three-term model, selected from more than 266 million models, includes the predictors Coprococcus eutactus at 24 months of age, Bifidobacterium at 36 months of age, and language development at 24 months. The top 20 four-term models, selected from more than 77 billion models, consistently include Coprococcus eutactus abundance at 24 months, while 14 of these models include the other two predictors as well. Mann-Whitney U tests further suggest that the abundance of gut bacteria in language non-impaired children (n = 78) differs from that in language impaired children (n = 61) at 24 months. While obligate anaerobic butyrate-producers, including Coprococcus eutactus, Faecalibacterium prausnitzii, Holdemanella biformis, Roseburia hominis are less abundant, facultative anaerobic bacteria, including Granulicatella elegans, Escherichia/Shigella and Campylobacter coli, are more abundant in language impaired children. The overall predominance of oxygen tolerant species in the gut microbiota of Ugandan children at the age 24 months, expressed as the Metagenomic Aerotolerant Predominance Index (MAPI), was slightly higher in the language impaired group than in the non-impaired group (P = 0.09).ConclusionsApplication of the all-subsets regression methodology to microbiota data established a correlation between the relative abundance of the anaerobic butyrate-producing gut bacterium Coprococcus eutactus and language development in Ugandan children. We propose that the gut redox potential and the overall bacterial butyrate-producing capacity could be factors of importance as gut microbiota members with a positive correlation to language development are mostly strictly anaerobic butyrate-producers, while microbiota members that correlate negatively, are predominantly oxygen tolerant with a variety of known adverse effects.
The comprehension of deictic terms in normal and language impaired children
