Exploring the gut microbiome in Cambridgeshire AN inpatients v1.8
Research type
Research Study
Full title
Exploring the gut microbiome as a biomarker for Cambridgeshire patients with anorexia nervosa- a pilot exploratory study
IRAS ID
316621
Contact name
Passent Helal
Contact email
Sponsor organisation
CPFT
Duration of Study in the UK
0 years, 11 months, 31 days
Research summary
In a healthy individual, the proportion of useful ‘good’ and harmful ‘bad’ bacteria is usually well-balanced, resulting in their coexistence without problems. However, a disturbance in this balance, brought on by diet, infections, age, medications, exercise, smoking etc. have been shown to have detrimental effects on health. In patients with anorexia nervosa, where caloric intake is usually not enough, this balance was shown to be disrupted with overall less diversity in the gut bacteria. This is presumed to, not only increase susceptibility to several illnesses, but to also interfere with nutrient absorption, energy expenditure, and the maintenance of a malnourished state despite treatment. The genetic make up of gut bacteria, usually referred to as the microbiome is hence becoming an important area of study.
The aim of this study is to examine whether early stages of microbiome change can predict clinical improvement, in terms of BMI and/or eating disorder psychopathology (via the Eating Disorder Examination Questionnaire (EDE-Q) scores/subscores) at a later stage of an inpatient admission. If gut microbiome was able to predict outcomes, this may mean it can be further explored for use as a biomarker in patients with anorexia nervosa. This may help to predict the progression of some patients to severe anorexia nervosa and aid with early intervention to reduce the risk of mortality. Future early intervention might be in the form of supplementation with pre/probiotics or fecal matter transplantation to restore the microbiome and body weight.
We plan on collecting blood and stool samples from inpatients with severe anorexia nervosa, identifying their gut microbiome and some variables influencing it at baseline, at 4 weeks during recovery, and by the end of the study at 12 weeks.
This is an exploratory single site observational study.
Summary of study results:
Anorexia nervosa is a mental disorder that is characterised by excessive worrying about body weight, reduced food intake, weight loss, and low body weight. It is often accompanied by compensatory behaviours in the form of over-exercising or self-induced vomiting. Standard treatment is provided in the form of nutritional rehabilitation with the aim of weight restoration and psychological support. However, this is not effective in a large group of patients who continue to live with anorexia nervosa impacting their ability to engage in day-to-day life. In addition, the rates of death because of complications from anorexia nervosa continue to be highest among other mental disorders.
The lack of effective treatments available may be due to the complex and unclear mechanism by which anorexia nervosa develops and continue to persevere. Research into the role of microorganisms, such as bacteria, inhabiting our gut showed changes in the numbers and quality of these microorganisms. It is believed that a disruption in the balance of ‘good’ and ‘bad’ bacteria may be connected to anorexia nervosa. In this case-series, we characterised changes in the gut microbiome in three individuals with anorexia nervosa who were receiving inpatient treatment. Individuals provided stool samples early after admission and 4-12 weeks later.
Results showed a higher ratio of Firmicutes to Bacteroidetes at both time points (these two bacterial phyla make up normally around 90% of our gut bacteria but are thought to be more balanced in healthy states). Hence, this suggests a possible imbalance in the bacterial composition. In the second samples, provided after more treatment was received while in hospital, this ratio reduced, indicating a possible improvement in the normal balance of gut bacteria.
Due to the small sample size, and no healthy control groups to compare to, it is difficult to make any conclusions. More larger studies are needed to validate this.REC name
London - South East Research Ethics Committee
REC reference
22/PR/0751
Date of REC Opinion
24 Aug 2022
REC opinion
Further Information Favourable Opinion