A paper by nutritional microbiologist David Sela, food science, and colleagues at Harvard and Arizona State University was recently named one of the top five most viewed papers of 2017 in the open access journal, PeerJ, in four topic areas: food science and technology, gastroenterology and hepatology, nutrition, and pediatrics. The article, “Handling stress may confound murine gut microbiota studies,” had 1,553 views over the year.
Sela says, “We knew that people were excited about it, but I did not realize how enthusiastically it was received across these disciplines.As our work tends to be cross-disciplinary, it is gratifying that multiple fields find value in our article. These are precisely the target audiences that we seek to have a scientific conversation with.”
Published last January, the paper provides evidence that the stress of handling – including in this case administering human milk sugars, oligosaccharides, by an invasive technique called oral gavage to mouse pups – may induce enough stress to alter the animal’s gut microbiota profile, confounding experimental results in such studies.
The authors say they hope to introduce a less-invasive technique for administering nutrition or drugs, for example, to remove the potential confounder of gavage stress.
Their study tested two methods, active and passive, of solution administration to newborn mice and the effects on their gut microbiome. The researchers collected gastrointestinal tracts from five dams, six sires and 41 pups over four time points, plus seven fecal pellets from unhandled pups and two pellets from unhandled dams. They used quantitative real-time polymerase chain reaction to quantify and compare the amount of stress biomarkers present.
Sela and colleagues report observing a significant difference between the amount of one biomarker in pups receiving water passively and those receiving the human milk sugars actively, by gavage, and significant differences between the fecal microbiota from handled and non-handled mouse pups.
“From our results, we conclude even handling pups for experimental purposes, without gavage, may induce enough stress to alter the murine gut microbiota profile. We suggest further studies to examine potential stress effects on gut microbiota caused by experimental techniques. Stress from experimental techniques may need to be accounted for in future gut microbiota studies.”