Given that the gut produces the majority of the bodys serotonin and communicates directly with the brain via the vagus nerve, improvements in gut integrity naturally translate to improved neurological function
Other groups who may benefit include: Patients following gastric surgery (gastrectomy, bariatric procedures) where intrinsic factor production or absorption sites are compromised Individuals with malabsorption disorders such as Crohn's disease, coeliac disease, or chronic pancreatitis Strict vegans and vegetarians with dietary insufficiency, though oral supplementation is usually tried first Elderly patients with atrophic gastritis or reduced gastric acid production Patients on long-term metformin or proton pump inhibitors, which can impair B12 absorption Individuals with nitrous oxide exposure (recreational or medical), which can cause functional B12 deficiency Diagnosis typically involves serum B12 measurement, with levels below approximately 148 pmol/L (though thresholds vary between laboratories) generally indicating deficiency
Patients should be counseled on strategies to minimize these effects, including eating smaller meals, avoiding high-fat foods, and maintaining adequate hydration
(2025) Suicide and suicide attempt in users of GLP-1 receptor agonists: a nationwide case-time-control study, eClinicalMedicine
