We all have landmarks in our lives. It might be when we heard Elvis had died (I was in a restaurant kitchen in Cornwall where I was working as an underage waitress, in case you’re interested).
For dietitians – and sufferers of a myriad of bowel conditions – 1995 was a landmark year.
Prebiotics on the map
1995 was the year that the concept of prebiotics was introduced. We all have more bacterial cells in our bodies as we do human cells – the average person has around 100 trillion bacterial cells. The majority of these live in our gut, where they help us to digest food – not only are most gut bacteria harmless, we couldn’t survive without them. But not all bacteria are equal, and a shift in the balance of ‘good to bad’ bacteria has been linked with a host of medical conditions from obesity and heart disease to bowel problems and cancer.
The (really) bad stuff
Some bacteria can clearly wreak havoc if they multiply in your gut. These include C. diff, which caused 12,681 cases in hospitals in England alone in 2016. The main cause of C. diff infection? Giving antibiotics which kill off the good bacteria in the gut, allowing the pathogens to thrive.An imbalance of gut bacteria has now been placed firmly in the frame as a – if not the main – cause of irritable bowel syndrome, or IBS. And that means the race is on to discover how we tame our bugs.
A taste for the good stuff
We’ve discovered that good bacteria, like Lactobacilli and Bifidobacteria, are more likely to gain the upper hand if they’re ‘fed’ certain foods. Foods such as onions, beans, leeks, Jerusalem artichoke and garlic are rich in these non-digestible carbohydrates called prebiotics. Prebiotics are resistant to stomach acid and digestive enzymes, so reach the colon unchanged.
For most healthy people, simply increasing the amounts of prebiotic-rich foods, along with a generally balanced diet, should be enough to keep our good bacteria thriving. But most of us need antibiotics at some point, despite the average GP’s efforts to keep inappropriate prescribing to a minimum. And with resistant bacteria on the rise, complications from taking antibiotics is an ever-increasing risk.
Likewise, several studies suggest that people with IBS have an overabundance of bad bacteria, which may not cause acute severe illness like salmonella, but which may bear the blame for their bloating and pain.
The below information was not included in the article by Sarah Jarvis.
A review of the medical literature found that taking people given probiotics were 42% less likely to develop antibiotic-associated diarrhoea – for every 13 people who took them, 1 was saved from getting diarrhoea when they otherwise would have had it.
The good news is that probiotics and prebiotics are safe; a review of 63 trials, involving over 8,000 people, found that “Used alongside rehydration therapy, probiotics appear to be safe and have clear beneficial effects …” The problem researchers found in terms of benefit was that they couldn’t tease out which probiotics were helping, and there are significant differences between types in terms of which good bacteria they nurture.
IBS – are gut germs to blame?
In recent years, much of the research into irritable bowel syndrome (IBS) has focused on this bacterial balancing act. Many bad bacteria, like yeast, ferment food in the colon, producing gas as they do so. Anyone who has poured a pint of beer or opened an ancient yoghurt pot knows that the result is gas – lots of gas.
Do pro/prebiotics actually work?
The fact that worldwide the probiotic/prebiotic market is predicted to be anywhere from $28 billion to $42 billion in 2017 tells you everything you need to know about how many people swear by their benefits. But really high-quality evidence is remarkably scarce, not least because the people in the studies are difficult to compare.
Sure, millions of people are convinced probiotics and prebiotics work. But people say the same about medicines, yet wouldn’t dream of taking them unless they’d gone through proper scientific studies to prove it. The placebo effect applies to pro/prebiotics as well as medicines – if people think they’ll work, they’re more likely to report that they feel better.
Because probiotics and prebiotics aren’t subject to the control of drug agencies, they don’t need to go through the same rigorous tests as prescribed medicines. But some companies have done the studies anyway.
What does it mean to me?
If you have IBS and have brand loyalty to one brand, all this evidence may not mean anything at all. But if you’re still struggling – as so many people with IBS are – you may be wondering which product, if any, is worth taking. Looking at the science, rather than the fluff, there are several options that seem to make a genuine difference. What you do with this information is up to you.
Credit: Dr Sarah Jarvis