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µ-opioid receptors are expressed in many organs, notably the gastrointestinal tract. Opioid receptors play a physiologically important role in controlling gastrointestinal function, including regulating gastrointestinal motility, mucus production and hormone/incretin production.

Gastric Motility

BCM-7 as a µ-opioid receptor agonist, decreases gastrointestinal motility in part, by reducing the frequency and amplitude of intestinal contractions. BCM-7 in particular can mimic the effects of opioids, in some cases leading to constipation. The role of opioid receptors in mediating these effects was confirmed, as co-treatment with an opioid receptor antagonist (Naloxone) which suppressed the effects of BCM-7.

Mucus Secretion

Gastrointestinal mucus secretion is at least partly regulated by opioid receptors; it is suppressed by opioid antagonists, such as naloxone and increased by morphine. Gastrointestinal mucus serves as a protective barrier between the epithelium and the lumen, containing potentially harmful compounds and microorganisms, as well as a lubricant to help food passage.

Studies have shown that dietary peptides, including BCM-7, stimulate mucus release via μ- opioid receptors. Although the clinical relevance of this effect is not fully understood, excessive mucus secretion may interfere with commensal bacteria or alter gastrointestinal uptake of nutrients or drugs.

Gut-Associated Immune System

Another component of the gut's immune system is the lamina propria lymphocytes. These cells play an important role in innate immunity and protection against pathogens in the intestinal lumen.

However, abnormal activity of the gut's immune system is implicated in the aetiology of gastrointestinal disorders, such as inflammatory bowel disease and food allergies. At least two studies have shown that BCM-7 alters lymphocyte proliferation in vitro through a pathway mediated by opiate receptors. The first of these studies showed suppressive effects of BCM-7 on lymphocyte proliferation at all concentrations tested, while the second study showed suppressive effects of low BCM-7 doses and stimulatory effects at higher doses. Considering that both studies were performed in vitro, more studies are needed to confirm the physiological relevance of these immunomodulatory effects of BCM-7 in animals and humans


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