Our guts play host to 100 trillion types of friendly bacteria – known as the gut microbiome – and these play an active role in digestion and protecting our immune systems.
Scientists now believe these 'friendly' bacteria not only benefit gut health and digestion, but may play a role in other aspects of health. A growing body of research suggests they may help with obesity, diabetes, eczema, rheumatoid arthritis and irritable bowel syndrome.
What are prebiotics and probiotics?
Probiotics are live bacteria and yeasts which can be taken as a supplement. They contain bacteria which are like those that inhabit the colon. Prebiotics are preparations of complex sugars that help the 'good' bacteria in probiotics to thrive.
Probiotics can be destroyed by your stomach acid or bile salts, although the strains lactobacillus and bifidobacteria have been found to be highly resistant.
Which bacteria are best?
Not all bacteria are equally effective so you need to check that you're taking a type of prebiotic/probiotic that is backed up by high quality research. Three strains of lactic acid-producing bacteria, which are commonly found in fermented foods, are:
• Lactobacillus acidophilus
• Bifidobacteria lactis
• Lactobacillus rhamnosus
These strains, often referred to as 'live' or ‘friendly’ bacteria, are the top three positive bacteria, which aid digestion by breaking down enzymes and other proteins found in food.
Here are some of their benefits:
• Aid lactose digestion: These three strains of bacteria can improve the digestion of lactose (a sugar found in milk and dairy products) and ease symptoms in those who are lactose intolerant.
• Protect against intestinal infections: When the balance of the gut is disrupted, you can suffer diarrhoea or constipation symptoms. Lactobacillus acidophilus, Bifidobacteria lactis and Lactobacillus rhamnosus, can provide a protective action against the potentially harmful microbes. One review found that the strains Bifidobacteria lactis and Lactobacillus rhamnosus could help prevent acute infectious diarrhoea in children.
• Ease symptoms of IBS: Recent research suggests these strains of bacteria may help reduce some of the symptoms of IBS. One study found IBS patients who were given a probiotic mixture, containing Lactobacillus acidophilus, Bifidobacteria lactis and Lactobacillus rhamnosus had improved diarrhoea symptoms.
4 ways to get your gut-healthy
Here's how to restore and improve your gut bacteria.
• Choose foods with healthy bacteria: Fermented foods, such as, Kefir, cottage cheese, live-bio yogurt, sauerkraut and miso, are rich sources of lactic-acid producing bacteria.
• Control stress: One study, published in Brain, Behaviour and Immunity, found stress can change the balance of bacteria that naturally live in the gut, contributing to conditions, such as IBS.
• Avoid foods that disturb the balance: Sugar, caffeine, fatty and processed foods can all upset the balance of bacteria in the gut. Replace them with gut bacteria-friendly foods, which play a role in keeping the gut flora fed and nourished (they act as prebiotics feeding 'friendly' bacteria in the digestive system). These include artichokes, bananas, polenta, broccoli, blueberries, miso soup, tempeh, and beans.
• Take a prebiotics/probiotics supplement: friendly bacteria help to restore the natural balance of bacteria in the gut. One study found taking prebiotics reduced levels of the stress hormone cortisol, in healthy volunteers.
Other supplements for supporting gut health
• Globe artichoke extracts contain inulin, a prebiotic fibre that increases levels of some 'good' bacteria in the gut, as well as lowering cortisol.
• Milk thistle is available in the UK as a registered traditional herbal medicine to help relieve the symptoms of over-indulgence and indigestion, providing a natural way to help cure an upset stomach.
• Aloe vera may help with digestive discomfort and studies show it could help certain symptoms of IBS.
• Green tea stimulates and improves digestion. One study found catechins in green tea increase the activity of the digestive enzyme pepsin, which breaks down proteins in the stomach.