Longitudinal Changes in the Oral and Gut Microbiome of Individuals With Alcohol Dependence

The microbiome exists in a complex symbiotic relationship with its human host, the
characterization of which is imperative for understanding a myriad of diseases. Until
recently, much of gut microbiome research has focused on gastrointestinal disorders. Recent
research, however, has implicated the gut microbiome in psychological disorders as well
through a proposed gut-brain axis. Of particular interest is characterization of the
microbiome of individuals with severe alcohol use disorders, as alcohol has been known to
profoundly alter the gut microbiome. For many years, scientists have theorized a connection
between the proinflammatory mediators produced by ethanol consumption, liver disease and the
gut microbiome. This study represents the first instance in which the naturalistic time
course of changes in the gut microbiome will be followed in alcoholics in whom detailed
history of alcohol consumption and diet have been obtained. We hypothesize that the gut
microbiome will renormalize spontaneously and without specific intervention over a time frame
of one or two weeks. Alcoholic patients also suffer from serious oral hygiene problems
associated with alterations in oral microbial flora. We hypothesize that abnormalities in the
oral microbiome will be detectable on admission, and that these will also rapidly renormalize
with abstinence and resumption of ordinary diet and oral hygiene. If not, the findings in
this study could point to the need for other interventions, such as administration of
probiotics. Twenty evaluable participants admitted to the Clinical Center for alcohol
detoxification will be enrolled. All patients will be admitted under the Unit and Clinic
Evaluation, Screening, Assessment, and Management protocol (14-AA-0181), which includes
adults 18 years of age or older seeking treatment for severe alcohol use disorders. Oral
(tongue brushings) and gut (stool) specimens will be collected daily until for the first
week. And then once a week for 28 days. Demographic characteristics, detailed drinking and
dietary histories, measures of addiction severity, comorbid mental disorders, and metabolic
indicators of other disease will be collected for correlation with microbiological results.
Dietary records will include use of probiotics. Exclusion criteria include use of
antibiotics, corticosteroids or immunosuppressive agents within the past month. Informed
consent will be obtained after consent for the screening and treatment protocol (14-AA-0181)
and in accordance with policies protecting participants with impaired decision-making.
Microbial identification will include 16S rRNA analysis and a validated Next Generation
Sequencing analysis pipelines. Statistical comparisons between each patient s oral and gut
microbiome samples will be evaluated and all results from this population will also be
compared to published microbiomes in both healthy volunteers as well as existing data from
alcohol dependent individuals. Participants will be compensated for research-related
discomfort and inconveniences in accordance with NIH guidelines.

- INCLUSION CRITERIA:

- At least 18 years of age

- Willing to provide consent

- Consented on screening and research protocol 14-AA-0181

- Admitted to the NIH CC for inpatient detoxification treatment

EXCLUSION CRITERIA:

- Currently using or have used any of the following drugs within the last month by self
report:

- Antibiotics

- Corticosteroids: inhaled, oral, intravenous or intramuscular

- Immunosuppressive or cytotoxic agents

- Large doses of probiotics such as supplemental probiotics (ordinary dietary components
such as beverages/milk or yogurt DO NOT APPLY)

- Major surgery of the GI tract with the exclusion of cholecystectomy and appendectomy
in the past 5 years.

- Any bowel resection at any time.

- History of active uncontrolled gastrointestinal disorders or diseases including
inflammatory bowel disease, ulcerative colitis, Crohn s disease, and/or infectious
gastroenteritis, colitis, or gastritis (per patient s report of whether or not they
have been diagnosed by a physician).

- Enrolled in any investigational study that might affect the microbiome.

- BMI greater than or equal to 30 kg/m2

Some of these exclusionary criteria have been adapted from the Human Microbiome Project
[40]. All exclusion measures will be collected from self-report.