A new study in mice assists discuss why gut microbiomes of breastfed infants can vary considerably from those of formula-fed infants.
The research study, “Dietary Sphinganine Is Selectively Absorbed by Members of the Mammalian Gut Microbiome,” was published in July in the Journal of Lipid Research.
Sphinganine from milk Johnson Lab/Provided A new strategy allows scientists to track specific nutrients as they are taken up by gut microbes in a mouse’s digestive tract. The image reveals particular microorganisms (red) taking in a nutrient typical in human milk called sphinganine; blue microorganisms have actually not taken it in.
The paper explains an innovative method developed at Cornell to track the fate of metabolites– nutrients formed in or essential for metabolism– through a mouse’s gastrointestinal tract and determine how they communicate with specific gut microorganisms.
” We believe the methods are expandable to many different microbiome systems,” said senior author Elizabeth Johnson, assistant professor of dietary sciences in the College of Agriculture and Life Sciences. She kept in mind that researchers investigating impacts of a high-fat vs. low-fat diet plan, or a keto diet, may use the method to track metabolites.
The approach might reveal how particular metabolites promote particular germs. This could enable nutritional experts to prescribe that patients consume foods containing particular metabolites to intentionally change the structure of their microbiomes, Johnson said.
Human milk and numerous other foods contain a class of lipid metabolites called sphingolipids. Previous research study recommended that these metabolites assist shape a baby’s microbiome, however it was not known if they in fact communicate with the microbiome.
The research study recognized two types of gut microbes, Bacteroides and Bifidobacterium, that utilize sphingolipids for their own metabolic process.
While extremely little is known about the specific functions of gut microbes in human health, Bacteroides have been implicated in both beneficial and not-so-beneficial results, depending on context.
They’re likewise an extremely popular non-prescription probiotic.
” Our laboratory is very interested in how the diet plan connects with the microbiome in order to really understand how you can best modulate it to have positive results on health,” Johnson said. “In this research study, we had the ability to see that yes, these dietary lipids that are a big part of [breastfed] babies diet plans, are interacting rather robustly with the gut microbiome.”
Sphingolipids stem from three main sources: diet plan; bacteria that can produce them; and many host tissues.
Johnson, in addition to first author Min-Ting Lee, a doctoral trainee, and Henry Le, a postdoctoral scientist, both in Johnson’s lab, produced a technique to particularly track dietary sphingolipids as they passed through the mouse gut.
” We customized synthesized the sphingolipid we contributed to the diet,” Johnson said. “It is nearly similar to ones originated from breast milk however with a small chemical tag so we could trace the place of the sphingolipid once it was consumed by the mice.”
Lee then used a fluorescent label that attached to cells or microorganisms that took in the tagged lipid, such that any germs that had used up sphingolipids illuminated red. Microorganisms from the mice’s microbiomes were then isolated and examined. Populations with red microbes were separated from the others, and these were then genetically sequenced to determine the species of bacteria.
With further investigation, Le had the ability to recognize the metabolites that Bacteroides and Bifidobacterium produce when exposed to dietary sphingolipids. Further examinations are underway to identify whether these microbially-produced metabolites are helpful for baby health.
Johnson just recently received a five-year, $1.9 million Maximizing Detectives’ Research Study Award from the National Institutes of Health (NIH) to expand on this work, to better understand how lipid-dependent host-microbe interactions impact human health.
The study was supported by seed funds from the Genomics Facility of the Biotechnology Resource Center at Cornell’s Institute of Biotechnology.