When Professor Glenn Gibson wants a laugh he types “probiotics” into Google. Gibson, an expert in probiotics, based at Reading University, is astounded by the pseudo- scientific myths that have sprouted around his specialist subject. The makers of one probiotic product claimed that it takes oxygen into your body, a mission impossible given that the bacteria listed are anaerobic and so die when they come into contact with oxygen.
Probiotic drinks are the pocket-sized health-kick of the day. TV adverts for these 100g “gulps of goodness” hint at astonishing changes in wellbeing and sales have shot up. Today, probiotic drinks are among the bestselling products in supermarkets. Müller Vitality has had a 44 per cent growth in volume sales since this time last year and sales of Danone’s Actimel have increased 73 per cent in the past 12 months. It’s a health habit that is worth £238 million in the UK market alone.
But we’ve never needed these “active health drinks” before, so do we really need them now? Or are they just a money-making exercise cashing in on the worried well? And what are the concrete health benefits beyond the “feel-good” claims on the packaging of probiotic products? Actimel’s advertising campaign, for example, claims that you will “feel the difference in two weeks”, though the nature of that “difference” is hard to define. The “fortnighters” that I talked to either raved about it or dismissed it. Mandy Tuininga, an accounts manager, (pictured left) is one of those converted to probiotics. She’s been taking them for the past 18 months: “I notice their effect most if I don’t take them — I feel more sluggish, both physically and mentally. Of course, it may all be psychological, but either way it makes me feel better.”
Danone says that of the 9.5 million consumers who bought its probiotic Actimel between September and October last year, only 45 people asked for their money back because they didn’t feel any different.
Simplified, a probiotic drink contains live “friendly” bacteria that gang up with the existing good guys in the gut and fight the baddies to improve balance, overwhelming the bad bacteria and helping digestion as well as preventing other gut-related problems, such as diarrhoea and bowel disease.
Or that’s the idea. But the stomach is extremely acidic and one argument against taking probiotic drinks is that the friendly bacteria don’t survive once inside it. “The bacteria must be quite robust to go through the stomach and reach the large intestine, where most of the gut bacteria live,” agrees Claire Williamson, a nutrition scientist at the British Nutrition Foundation.
When Jeremy Hamilton-Miller, a now retired professor of microbiology who has studied probiotics, analysed the contents of some of the 50 or so probiotic supplements last year, he found that only a third contained the billions of bacteria claimed on the package label. “However, the bigger companies which advertise on TV or radio will have passed strict tests and will stick to the proven strains — L Casei immunitas or BB-12 Bifidobacterium bifidum, for example — and quantities that do make it through to the large intestine,” he says. “They use independent academic research; ie, publically funded by a research council, peer reviewed and not subject to industry scrutiny before publication,” adds Zoë Dunford, of the Institute of Food Research.
And just when you thought you had got to grips with probiotics, along comes the synbiotic. This latest product contains both “good” probiotic bacteria and prebiotics, which are food for “good” bacteria.
“A huge fraction of probiotic bacteria never gets past the stomach because of its high acidity. Prebiotics don’t have this problem, so they provide a more efficient way to increase the friendly bacteria of the large bowel,” says Professsor Ian Johnson, of the Institute of Food Research. Both prebiotics and probiotics serve the same purpose in that they alter the gut microflora to be more beneficial, adds Professor Gibson. “It is just that prebiotics do so with what is already there; they feed the friendly bacteria, hence the survival issues over use of live bacteria in the diet are overcome.”
Prebiotics appear naturally in foods such as Jerusalem artichokes, garlic, onions, tomatoes, asparagus, chicory, bananas, leeks, cucumber, chickpeas and sunflower seeds. These stimulate the growth of lactic acid bacteria — such as Lactobacillus and Bifidobacterium — a large group of beneficial or friendly bacteria. “Probiotics plus prebiotics equals a powerful synbiotic combination that can help to maintain a healthy digestive system,” says Catherine MacDonald, a nutritionist who formerly worked at Müller.
But wouldn’t it be healthier just to eat the natural foods mentioned to get enough prebiotics? After all, the probiotic drinks on sale don’t only contain billions of friendly bacteria but also sugar, modified starch and colourings typical of ordinary yoghurts. “No,” says Professor Gibson, “because they are present only in low amounts and you need a typical dose of at least 5g a day — the equivalent of a sackful of onions — to get a prebiotic effect. Hence, the active ingredients are extracted (or synthesised) and put into other foods or used as supplements. It is impossible to get realistic probiotic or prebiotic levels without the drinks or supplements.”
So how have we managed to evolve this far if probiotics are so essential to our wellbeing? “We now aspire to live longer, healthier lives,” says Professor Johnson, “so we have different problems that may be influenced by gut bacteria. In particular, modern Western populations suffer from new immunological abnormalities such as inflammatory disease and asthma. Modifying the gut bacteria may have a role to play in prevention, but we have an enormous amount to learn. The development of rational, evidence-based probiotics and prebiotics is only just beginning”.
Professor Gibson agrees: “Ask someone with irritable bowel syndrome, bowel cancer or ulcerative colitis or food poisoning if we have evolved well enough not to need probiotic drinks. The way to reduce risk of these and other gut-related disorders is to fortify beneficial bacteria in the gastrointestinal tract. The probiotic approach is harmless, unlike many diet or drug interventions.”
