Trust your gut instinct
LISA SALMON FINDS OUT HOW ‘GOOD’ BACTERIA HELPS YOUR IMMUNE SYSTEM
A HEALTHY immune system is vital for keeping us well, and one proven way to support it is with probiotics.
We asked Professor Glenn Gibson, a professor of food microbiology at University of Reading, who’s studied probiotics and prebiotics extensively, and Dr Carrie Ruxton, a dietitian for the Health and Food Supplements Information Service (hsis. org), to tell us more about the friendly bacteria that live in our intestines, stomach and gastrointestinal tract...
WHAT ARE PROBIOTICS?
The World Health Organisation defines probiotics as microorganisms which when administered in adequate amounts confer a health benefit on the host”.
Dr Ruxton says: “Probiotics are live ‘friendly’ bacteria in food or supplement form that can alter the balance of our own gut bacteria – assuming they reach the gut intact.”
WHAT ARE THE HEALTH BENEFITS OF PROBIOTICS?
“Lots,” says Prof Gibson. “There are now over 26,000 research articles on their use. These include improved protection against gastroenteritis, reduced inflammation (hence the link to Covid), and boosting immunity – being harmless microbes, they’re good at stimulating non-specific immunity in the gut.
Specific diseases like irritable bowel syndrome and inflammatory bowel disease have been looked at and there’s currently immense interest in obesity and gut-brain interactions (cognitive function).”
Research by University of Plymouth last year found probiotic bacteria could help control the development and progression of colorectal cancer.
CAN YOU GET PROBIOTICS IN FOOD?
Probiotics are found in many fermented foods, including kefir (fermented milk), kombucha (fer “live mented sweet tea), kimchi (spicy fermented cabbage), tempeh (fermented soya bean patties), miso (fermented soya bean paste) and sauerkraut (fermented cabbage), as well as yoghurt.
“Probiotics can also be found in supplements and special drinks such as Yakult,” says Dr Ruxton.
“It’s good to combine probiotics with prebiotics – dietary substances that boost numbers of ‘friendly’ bacteria and promote their activity. The most accessible prebiotics are tea, onions, garlic and leeks. These have been proven to help rebalance our gut microbiota.”
Prof Gibson explains that prebiotics are like fertilisers for live probiotic microbes already in the gut.
WHO SHOULD TAKE PROBIOTICS?
Dr Ruxton says UK diets tend to be low in fibre, fruit and veg and high in animal protein, “which doesn’t do your gut microbiota any good”.
“However, people who are eating their five-a-day fruit and veg, and getting two to three daily servings of fibre-rich foods like wholegrain bread, pasta and rice, or high-fibre breakfast cereal, plus a few servings of fermented foods a week, should have a healthy gut microbiota.
“Everyone else should consider adapting their diets, or taking a probiotic supplement.”
ARE THERE ANY PROBLEMS THAT CAN BE CAUSED BY PROBIOTICS?
Dr Ruxton says people who are immunosuppressed should avoid probiotics because even ‘good’ bacteria, which would be harmless in most people, has the potential to cause infection in those with a suppressed immune system.