Intestinal microbiota, executive functioning and micronutrient status in enduring anorexia nervosa: a pilot study

Anorexia nervosa is a severe psychiatric disorder marked by extreme dieting and
low body weight. This extreme dieting may affect the diversity and composition
of the intestinal microbiota (microorganisms that inhabit the human gut).
Recent studies demonstrated the presence of a so called gut-brain axis;
intestinal microbiota seem to affect emotional behavior and were associated
with cognitive functioning. Anorexia nervosa itself is also associated with
cognitive functioning, in particular deficits in executive functions are
common. Executive functions are higher order control functions in the brain
that play a role in self-control, self-regulation, decision making, and
problem-solving. Moreover, the extreme dietary restrictions in anorexia nervosa
may lead to insufficiencies of vitamins and minerals.

The current pilot study aims to investigate whether diversity and composition
of the intestinal microbiota are different in patients with enduring anorexia
nervosa compared to matched controls. Furthermore, this study aims to explore
whether diversity and composition of the intestinal microbiota is associated
with executive functioning and/or micronutrient status (in patients with
enduring anorexia nervosa).

Observational pilot study, with a cross-sectional case-control design in 20
participants with enduring (at least two year) anorexia nervosa) and 20
controls (partner/family member/room mate from same house). The study consists
of three parts: 1. collecting a stool sample at home, with a special collecting
kit, and bringing this sample to the appointment at GGZ Rivierduinen Ursula; 2.
online completion of a number of questionnaires and a food diary during three
days; 3. a visit to GGZ Rivierduinen Eetstoornissen Ursula for completing the
neurospychological (computer)tasks, the dietary history and the blood
extraction at the LUMC (for micronutrient assessment).

Risks for taking part in this study are minimal. Participants can collect a
stool sample at home (a stool sample collection kit will be send by mail).
Self-report questionnaires and food diary will be completed online (duration 60
minutes; BRIEF-A-SR, DII, EDE-Q and IDS-SR). A single visit to GGZ Rivierduinen
Eetstoornissen Ursula to complete the neuropsychological tests (40 minutes;
Nederlandse Leestest voor Volwassenen, WCST, TMT, Go/NoGo and IGT), and the
dietary history (50 minutes) will be combined with the blood extraction at the
LUMC (three 4 ml whole blood EDTA tubes and one 8.5 ml SST tube (serum)) for
the micronutrient assessment. The participants will receive a financial
reimbursement of ¤ 10,00.