How your gut controls your immunity

Small daily habits support digestion, mood and your body’s defence system

Thursday, 19 March 2026: Your gut is running the show in ways you may never have imagined. Beyond digesting food, it is also the central hub of your immune system. Approximately 70–80% of immune cells are associated with the gut lining. When this barrier is strong, your body absorbs nutrients, fights infection efficiently and sends healthy signals to the brain. When it’s weakened, harmful substances can leak into the bloodstream, triggering inflammation and affecting overall health.

“The gut is where your immune system learns what to fight and what to tolerate,” says Anneke Meyer, pharmacist at South Africa’s first courier pharmacy, Medipost Pharmacy. “Supporting gut health isn’t just about digestion, it’s about strengthening your body’s defences and even protecting your mood.”

Modern lifestyles can disrupt the gut. Diets low in fibre and high in processed foods and sugar, frequent stress, along with poor sleep or certain medications – such as prolonged courses of antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), including ibuprofen and aspirin, or acid suppressants – can disturb the gut microbiome and weaken the intestinal barrier. Signs of imbalance often go unnoticed but may include persistent bloating, fatigue, new food sensitivities, sugar cravings and mood swings.

“The gut communicates directly with the brain via the gut–brain axis,” Meyer explains. “In fact, about 90% of the body’s serotonin, a key chemical for mood and digestion, is produced in the gut. That’s why gut health influences both your mental and physical wellbeing.”

“The gut lining functions as a selective barrier, absorbing nutrients while preventing harmful microbes from entering. A compromised gut barrier can result in low-grade systemic inflammation,” Meyer explains.

“Everyday choices like diet, hydration, sleep, and stress management influence your gut microbiome. Probiotics may be beneficial in specific situations, such as after antibiotic use or for certain gastrointestinal conditions, but they should be selected under the guidance of a healthcare professional, especially for individuals with weakened immunity.

“Improving gut health doesn’t need to be complicated or expensive,” says Meyer. “Small, consistent changes make a real difference.”

• Eat more fibre: Add one high-fibre food per meal, such as beans, lentils, brown pap, whole grains, sweet potato, spinach or cabbage.
• Stay hydrated: Sip water throughout the day, especially during long shifts.
• Move daily: Ten minutes of walking or stretching after work supports digestion.
• Prioritise sleep: Aim for regular sleep hours and practise a short stress-breathing exercise each day.
• Check medications: Ask your pharmacist how to protect your gut when taking antibiotics, non-steroidal anti-inflammatory drugs, or acid-lowering medicines.
• Use supplements wisely: Targeted probiotics, antioxidants, vitamins, or minerals can support gut health in specific cases, but always follow professional advice.

“Your pharmacist can guide you on the right probiotics, timing with antibiotics, and practical diet swaps,” Meyer adds. “Even small steps can have a big impact on your immunity and wellbeing. Seek immediate medical attention if you experience severe abdominal pain, high fever, bloody stools, sudden unintentional weight loss or persistent vomiting.”

Medipost Pharmacy offers advice and pharmaceutical care in all 11 official languages, assisting patients with safe, evidence-based options that fit their needs.

“Your gut is central to immunity, and small, consistent habits protect digestion, mood and overall defence. Medipost Pharmacy helps you put those habits into practice by offering medication counselling, selected supplements when appropriate, and nationwide courier delivery to keep treatment continuous and convenient,” Meyer concludes.

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