Interleukin-6 in Irritable Bowel Syndrome: From Pathophysiology to Therapeutic Outlook

Irritable bowel syndrome (IBS) is a prevalent functional disorder of the gastrointestinal tract that affects approximately 11% of people worldwide. The exact mechanisms underlying IBS remain unclear, but evidence suggests that low-grade inflammation is involved in its pathophysiology. Interleukin-6 (IL-6) is a key cytokine that mediates inflammatory responses in the intestinal mucosa and has been linked to the development of IBS. Our study aimed to provide an overview of the current knowledge on the role of IL-6 in IBS.

The present study was conducted based on a search on the PubMed database, where only 26 articles investigated the role of IL-6 in irritable bowel syndrome were found.

Our review revealed that patients with IBS had higher levels of IL-6 in their serum/plasma. Furthermore, increased expression of IL-6 mediated by cholinergic signalling was associated with increased abdominal pain/discomfort and bloating. More recently, an interaction between IL-6 and corticotrophin-releasing factor was shown to provide more insight into the mechanisms underlying IBS symptoms during stressful periods, which are experienced by almost two-thirds of patients with IBS. Elevated levels of IL-6 were also correlated with increased fatigue and intestinal inflammation. Targeting IL-6 expression or IL-6 signalling pathway using probiotics, vitamin D3 or a replacement diet may offer a novel therapeutic strategy to improve IBS symptoms, abdominal pain, bloating and fatigue after consumption of ancient wheat products.

Further studies are needed to elucidate the causal relationship between IL-6 and IBS, as well as the molecular pathways and cellular targets of IL-6 in the gut.