Your digestive system is one of the most complex and underappreciated parts of the human body. Stretch it out and it would cover the area of a tennis court. Home to over 100 trillion bacteria, it processes around 30 tonnes of food over a lifetime — and influences everything from your immune response to your mental health.
The Journey of a Meal
Digestion begins the moment food enters your mouth. Chewing breaks food into smaller pieces while salivary amylase starts breaking down starch. Swallowing propels food into the oesophagus, which uses muscular contractions (peristalsis) to push it into the stomach. In the stomach, hydrochloric acid and pepsin break proteins down over 2–4 hours. The semi-digested mixture (chyme) then passes into the small intestine — the primary site of nutrient absorption. Here, bile from the liver and enzymes from the pancreas complete digestion of fats, proteins and carbohydrates. The large intestine reabsorbs water and electrolytes, and the gut microbiome ferments undigested fibre — producing short-chain fatty acids that feed colon cells and support systemic health.
The Gut Microbiome: Your Internal Ecosystem
The gut microbiome contains 100 trillion microorganisms — bacteria, viruses, fungi and archaea — that together weigh approximately 1.5kg. A diverse, balanced microbiome is linked to: robust immune function (70% of the immune system resides in gut-associated lymphoid tissue), better mental health (90% of serotonin is produced in the gut), efficient metabolism, lower inflammation, and reduced risk of chronic disease. Factors that harm microbiome diversity: antibiotics, processed food, high sugar intake, chronic stress, lack of fibre, and insufficient sleep.
Common Signs Your Digestion Needs Support
- Persistent bloating or abdominal distension
- Irregular bowel habits (too frequent, infrequent, or variable)
- Recurrent heartburn or acid reflux
- Excessive flatulence
- Food intolerances developing in adulthood
- Fatigue or brain fog after eating
- Unexplained skin problems (some eczema and rosacea have gut connections)
How to Support a Healthy Gut
Dietary fibre is the single most important dietary factor for gut health. The UK recommendation is 30g per day; most people consume around 18g. Both soluble fibre (oats, legumes, apples, flaxseed) and insoluble fibre (wholegrains, vegetables) are important. Fermented foods — natural yoghurt, kefir, kimchi, sauerkraut, miso — introduce live cultures that support microbiome diversity. Polyphenols — plant compounds in berries, dark chocolate, green tea, olive oil — feed beneficial bacteria. Adequate hydration — water is essential for stool consistency and bowel transit. Exercise — even moderate physical activity promotes gut motility and microbiome diversity.
When to See a Doctor
While most digestive symptoms respond to lifestyle changes or OTC treatment, certain symptoms require urgent medical assessment: unexplained significant weight loss, blood in stool (red or very dark), persistent vomiting, difficulty swallowing, severe or sudden abdominal pain, or symptoms in someone over 50 that have recently changed.
Huncoat Pharmacy stocks a comprehensive range of digestive health products. Browse our Digestion & Stomach range covering heartburn & indigestion, constipation, diarrhoea and IBS. Related reading: Heartburn & Acid Reflux Guide, Managing IBS.
At Huncoat Pharmacy: Pharmacy First – speak to a pharmacist, Browse all digestive health products.