Lumeng, J. | bioRxiv Science

bioRxiv2021

Diet Potentially Drives the Differentiation of Eating Behaviours via Alterations to the Gut Microbiome in Infants

Certain infant eating behaviours are associated with adverse health outcomes such as obesity. While a diet consisting of infant formula has been linked to higher-risk eating behaviours and changes in the gut microbiome, little is known about what role the gut microbiome plays in mediating eating behaviours. Using 16S rRNA sequences extracted from 96 fecal samples collected from 58 infants, we identified a subset of bacterial taxa that were more abundant in formula-fed infants, primarily composed of the phylum Firmicutes. The presence of these taxa correlated with a lower drive to eat (i.e., lower food responsiveness). Furthermore, short-chain fatty acid production pathways were significantly more abundant in formula-fed infants, negatively correlated with food responsiveness, and positively associated with relative abundance of the Firmicutes subset. Our results suggest that higher abundances of Firmicutes in formula-fed infants may decrease their food responsiveness through short-chain fatty acid production in the first four months of life. Taken together, these findings suggest a potential role for the infants diet in impacting eating behaviour via changes to the gut microbiome, which may lead to the development of novel interventions for the prevention of childhood obesity.

microbiology↗

bioRxiv2019

Chemical Impacts of the Microbiome Across Scales Reveal Novel Conjugated Bile Acids

A mosaic of cross-phyla chemical interactions occurs between all metazoans and their microbiomes. In humans, the gut harbors the heaviest microbial load, but many organs, particularly those with a mucosal surface, associate with highly adapted and evolved microbial consortia1. The microbial residents within these organ systems are increasingly well characterized, yielding a good understanding of human microbiome composition, but we have yet to elucidate the full chemical impact the microbiome exerts on an animal and the breadth of the chemical diversity it contributes2. A number of molecular families are known to be shaped by the microbiome including short-chain fatty acids, indoles, aromatic amino acid metabolites, complex polysaccharides, and host lipids; such as sphingolipids and bile acids3-11. These metabolites profoundly affect host physiology and are being explored for their roles in both health and disease. Considering the diversity of the human microbiome, numbering over 40,000 operational taxonomic units12, a plethora of molecular diversity remains to be discovered. Here, we use unique mass spectrometry informatics approaches and data mapping onto a murine 3D-model13-15 to provide an untargeted assessment of the chemical diversity between germ-free (GF) and colonized mice (specific-pathogen free, SPF), and report the finding of novel bile acids produced by the microbiome in both mice and humans that have evaded characterization despite 170 years of research on bile acid chemistry16.

microbiology↗