1. The study investigated the relationships between altered intestinal microbiota compositions and sleep behavior in mice through two methods: administering antibiotics to deplete gut bacteria and feeding a high-fat diet to alter bacteria. 2. Fifteen mice were divided into three groups - one treated with antibiotics, one fed a high-fat diet, and a control group fed a normal diet. Infrared video was used to monitor their sleep behavior. 3. By sequencing the genomes of the remaining gut microbes, the researchers aimed to relate changes in gut permeability, aquaporin-4 expression, and sleep behavior to specific bacterial populations to better understand how gut bacteria may regulate sleep and how reductions in gut bacteria diversity could impact sleep and health

1. Project Title: Induction of intestinal microbial imbalances through antibiotic gavage,
high-fat diet: effects on the microbiota-gut-brain axis and sleep behavior in mice
Oral Presentation: Jonathan Lendrum
Investigators: Jonathan Lendrum1
, Sumei Liu1
, Bradley Seebach1
, Barrett Klein1
and
Andrew Berns2
1
Department of Biology, University of Wisconsin- La Crosse
2
Department of Computer Science, University of Wisconsin- La Crosse
Abstract
Throughout human history, the purpose of sleep has been at the center of existential
enigmas. Newborns sleep an astounding 14 to 17 hours a day; and as adults, we require
nearly 1/3 of our lives to be spent asleep. The glymphatic system, a recently discovered,
water-based drainage system for neural tissues that is active during sleep phases—but
inactive during periods of wakefulness—offers strong evidence for the evolutionary
importance of mammalian sleep. When we sleep, the glymphatic system functions as a
sink for the brain, using watery cerebrospinal fluid to wash away harmful extracellular
waste products (such as beta-amyloid associated with Alzheimer’s disease) that
accumulates in the compact spaces of highly sensitive brain tissues during waking hours.
In this way, a good night’s sleep may literally clear the mind, a property likely
responsible for the restorative properties of sleep. Furthermore, in the last decade
mounting evidence suggests complex interactions between hosts and their microbial
communities, known as the microbiota-gut-brain axis, play a critical role determining
health and disease states. Our study investigates multiple relationships between altered
compositions of intestinal microbiota and sleep behavior in a pilot study using fifteen
male (C57BL/6) mice. During summer 2015, three groups of five mice were individually
housed in cages custom-fitted with an infrared video surveillance system. We then
gavaged five of the mice with a broad-spectrum antibiotic cocktail consisting of
ampicillin, neomycin, metronidazole and vancomycin to deplete gut microbiota. To a
second group of five mice we used high-fat (60% kcal) diet feeding, which has been
shown to alter bacteria compositions in the gut. The final five mice served as the control
group and were fed a calorically matched low fat diet. By sequencing the genomes of the
remaining microbes, we can relate the changes in gut permeability, aquaporin-4
expression and sleep behavior to certain populations of gut bacteria. The discovery of the
glymphatic system and improving knowledge of the microbiota-gut-brain axis provides a
possible, explanatory link for how and why bacterial populations may regulate sleep
phases, and why reduction in the diversity of bacteria in the gut (as a result of poor
nutrition, or antibiotic exposure) may be associated with inefficient sleep, bowel
dysfunction and a range of nervous system disorders.