Chronic constipation most frequently arises as a functional disorder of at least 3 months
duration, the aetiology of which is multifactorial encompassing dietary and lifestyle factors
arising in the context of intact colonic motility. Confirmatory clinical diagnosis of chronic
constipation under this definition can be made with reference to the Rome IV criteria
encompassing assessment of stool frequency, quality, straining etc.
Whilst broadly prevalent across the population, constipation is particularly troublesome in a
significant number of patients undergoing interventions for weight loss in obesity, be that
dietary, pharmacological or surgical. Calorie restriction per se, which is a common feature
of most interventions for obesity necessarily reduces stimulation of colonic motility by
impacting the frequency and intensity of colonic mass movements. Moreover, decreases in
dietary fibre during food restriction result in debulking of the stool.
Multiple dietary and pharmacological approaches to the management of chronic constipation are
available to mitigate the risk of constipation during weight loss and treat it when it
becomes manifest. However, these can often be poorly accepted due to gastrointestinal side
effects. Interestingly, the potential laxative properties of orlistat, a pancreatic lipase
inhibitor-based treatment for morbid obesity have been investigated in off-label studies in
the setting of idiopathic chronic constipation and constipation associated with opioid pain
medication and anti-psychotic (clozapine) therapy. Mechanism of action in these cases most
probably relates to the pro-kinetic and lubricatory effects of the increasing passage of
undigested fat to the colon. Based on these case series, the potential for weight loss
pharmacotherapy with in-built mitigation of associated constipation becomes an attractive
concept.
When digestive and absorptive processes are impeded or moved distally in the small intestine,
as can happen with respect to dietary triglycerides during orlistat therapy, satiety gut
hormone signal and quantity of food intake are affected. During an ileal infusion of a lipid
emulsion, healthy subjects ate a smaller amount compared to control infusions. A study in
healthy volunteers in which fat was delivered via a nasal tube to the duodenum, jejunum and
ileum found that the ileal treatment had the most pronounced effect on food intake and
satiety.
The investigators have used a new food encapsulation technology using natural food grade pea
protein, AnaBio©*, to deliver pure oleic acid to the distal small intestine showed
significant attenuation of food intake in association with enhancement of enteroendocrine
satiety hormone release. The results recorded an increase in the number of bowel motions over
the subsequent 24 hours in half of the participants. Subsequently, the investigators showed
that ingestion of a smaller 400kcal cargo of microencapsulated oleic acid resulted in
decreased hunger and food intake, no increase in the frequency of bowel motion but an
increase in stool softness.
Based on the above data the investigators are encouraged to proceed with the present study,
the main goal of which is therefore to investigate whether the 400kcal dose of encapsulated
fat delivered to the distal small intestine might be a useful supportive therapy in patients
engaged in intensive weight loss therapies and experiencing constipation as a consequence.