Drunk bugs: Chronic vapour alcohol exposure induces marked changes in the gut microbiome in mice.
The gut microbiota includes a community of bacteria that play an integral part in host health and biological processes. Pronounced and repeated findings have linked gut microbiome to stress, anxiety, and depression. Currently, however, there remains only a limited set of studies focusing on microbiota change in substance abuse, including alcohol use disorder. To date, no studies have investigated the impact of vapour alcohol administration on the gut microbiome. For research on gut microbiota and addiction to proceed, an understanding of how route of drug administration affects gut microbiota must first be established. Animal models of alcohol abuse have proven valuable for elucidating the biological processes involved in addiction and alcohol-related diseases. This is the first study to investigate the effect of vapour route of ethanol administration on gut microbiota in mice. Adult male C57BL/6J mice were exposed to 4 weeks of chronic intermittent vapourized ethanol (CIE, N=10) or air (Control, N=9). Faecal samples were collected at the end of exposure followed by 16S sequencing and bioinformatic analysis. Robust separation between CIE and Control was seen in the microbiome, as assessed by alpha (p<0.05) and beta (p<0.001) diversity, with a notable decrease in alpha diversity in CIE. These results demonstrate that CIE exposure markedly alters the gut microbiota in mice. Significant increases in genus Alistipes (p<0.001) and significant reductions in genra Clostridium IV and XIVb (p<0.001), Dorea (p<0.01), and Coprococcus (p<0.01) were seen between CIE mice and Control. These findings support the viability of the CIE method for studies investigating the microbiota-gut-brain axis and align with previous research showing similar microbiota alterations in inflammatory states during alcoholic hepatitis and psychological stress.
APC Microbiome Institute, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
Veronica L
VL
Peterson
Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
Nicholas J
NJ
Jury
APC Microbiome Institute, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland.
Raúl
R
Cabrera-Rubio
APC Microbiome Institute, University College Cork, Cork, Ireland.
Lorraine A
LA
Draper
APC Microbiome Institute, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland.
Fiona
F
Crispie
APC Microbiome Institute, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland.
Paul D
PD
Cotter
APC Microbiome Institute, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland.
Timothy G
TG
Dinan
Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA. Electronic address: holmesan@mail.nih.gov.
Andrew
A
Holmes
APC Microbiome Institute, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland. Electronic address: j.cryan@ucc.ie.
John F
JF
Cryan
D000437:Alcoholism / Q000382:microbiology; D000818:Animals; D041963:Bacteroidetes / Q000187:drug effects; D003013:Clostridium / Q000187:drug effects; D004195:Disease Models, Animal; D000431:Ethanol / Q000008:administration & dosage*; D005243:Feces / Q000382:microbiology; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D008297:Male; D008810:Mice, Inbred C57BL
D000431:Ethanol
Chronic alcohol; Microbiome; Microbiota-gut-brain axis; Vapour ethanol