Chronic Inflammation and Digestive Disorders: What's Really Happening in Your Gut

Intestinal inflammation: a broader spectrum than you might think

When people hear "intestinal inflammation," most immediately think of serious conditions such as Crohn's disease or ulcerative colitis. These inflammatory bowel diseases (IBD) do indeed involve intense, persistent inflammation of the digestive lining, with visible tissue damage and profound dysregulation of the immune system.

But there is another face of intestinal inflammation — more discreet, more insidious — found in irritable bowel syndrome (IBS). Here, there are no visible lesions on endoscopy, yet low-grade inflammation is very much present, disrupting the daily lives of millions of people.

IBS affects an average of 10% of the general population, with a higher prevalence in women. It is not a psychosomatic condition — even if stress worsens symptoms — but a functional disorder underpinned by complex biological mechanisms.

What happens inside an irritable bowel

Several inflammatory mechanisms have been identified in IBS, and they interact with one another in subtle ways.

Increased intestinal permeability, often referred to as "leaky gut," is one of the first players involved. When the intestinal barrier becomes too permeable, bacterial fragments and food antigens cross the mucosal lining and trigger a local immune response. The result: an influx of immune cells and the release of inflammatory mediators such as histamine, serotonin, and TNF-alpha.

Add to this dysbiosis — the imbalance of the gut microbiome that researchers have confirmed as a central factor in IBS pathogenesis. Depending on the subtype:

• In constipation-predominant IBS, there is an excess of Bacillota bacteria and a reduction in butyrate-producing bacteria — butyrate being a short-chain fatty acid with potent anti-inflammatory properties
• In diarrhoea-predominant IBS, an excess of Bacteroidota and Clostridia, combined with a deficit in Bifidobacteria, drives excessive fermentation, hydrogen and sulphide production, and inflammation

A lesser-known mechanism: the abnormal presence of trypsin-3 in the colon. This digestive protease directly irritates the intestinal mucosa and perpetuates the inflammatory cycle.

Finally, in around 30% of diarrhoea-predominant IBS cases, an excess of bile acids accelerates transit and contributes to local inflammation.

Diet: what fuels the fire

Certain foods and eating habits play a direct role in sustaining this low-grade inflammation.

• FODMAPs (fructose, lactose, inulin, polyols, etc.) are poorly absorbed in the small intestine and ferment in the colon, generating gas, bloating, and an inflammatory response. Metabolomic analyses have confirmed poor tolerance of these compounds in people with IBS.
• Emulsifiers found in ultra-processed foods increase the virulence of certain gut bacteria and weaken the epithelial barrier — a phenomenon demonstrated in recent research models.
• A diet low in fibre and high in fat and sugar reduces butyrate production and promotes pro-inflammatory dysbiosis.
• Stress, anxiety, and depression are not direct causes, but they significantly worsen flare-ups via the gut-brain axis.
• Infectious gastroenteritis can trigger post-infectious IBS, leaving the gut in a state of persistent inflammation.

A multifactorial approach to better management

Understanding that IBS is rooted in real biological mechanisms — rather than mere oversensitivity — changes everything about how it should be approached.

Evidence-based management strategies include:

• Dietary adjustment, particularly a low-FODMAP diet, which reduces fermentation and mucosal inflammation
• Supporting the microbiome through a diet rich in well-tolerated prebiotic fibres and, where appropriate, targeted probiotics
• Reducing ultra-processed foods to limit exposure to emulsifiers and other disruptors of the intestinal barrier
• Stress management to help regulate the gut-brain axis
• Medical follow-up to rule out organic pathology and personalise care

Key takeaways

Chronic intestinal inflammation is not exclusive to IBD. In IBS, it operates silently and at a low level, through dysbiosis, increased intestinal permeability, and very real immune mediators. Identifying your triggers — dietary, behavioural, and environmental — is the first step towards taking back control of your digestive health.

Gut Tracker helps you track your symptoms, identify your triggers, and adopt a gut-friendly diet tailored to your profile.