Nutrition

So, what’s the deal with probiotics really?

An expert weighs in on their side effects, benefits and if they actually work
Loading the player...

They’re the buzz of the supplement world, purported to bring health benefits beyond even our deepest understanding. And probiotics certainly do seem to hold a lot of promise, with researchers regularly digging up new evidence supporting the role of good bacteria in maintaining our wellbeing.

Boosting our digestive health and immunity, warding off colds and allergies, and keeping bowels healthy are just a few of the alleged benefits.

The only problem is that when commercial brands are tested, the results are often a little disappointing. Bacteria can get killed off or compromised by manufacturing processes, incorrect storage and passing through stomach acid. You need billions to have an impact. There’s the question of which strain is right for you.

So should you spend your hard-earned cash – some brands cost $50 or more a bottle – on fortifying your internal bacterial colonies?

And if so – with a huge range of different brands of probiotic drinks, powders and capsules on the market – how do you choose the right one?

Probiotic literally means “for life”, which is apt, given we are made up of bacteria. Yet in a germ-phobic society, in which antibiotics and anti-bacterials are commonplace, it’s no wonder we don’t have the range of bacteria living in our bodies that we might have in the past. Not that this is always bad: sanitisation and medicine are the main reasons many of us don’t routinely become sickened by or die of common infections anymore.

Nevertheless, our guts may have less variety and balance in their resident microflora, exacerbated by modern habits such as eating too many processed foods and not enough fibre. Many of us are likely to be out of kilter on the bug front, which affects the rest of our health.

Endocrinologist Katherine Samaras, Professor of Medicine at UNSW and a clinical fellow at the Garvan Institute of Medical Research in Sydney, says having the right type of bacteria is important.

“The right types of bacteria promote healthy metabolism and diminish inflammation, which can harm our health,” she says.

“The wrong types of bacteria cause systemic inflammation, which damages our arteries, promotes diabetes and fatty liver disease, and is considered to contribute to accelerated ageing, including cognitive [brain function] decline.

Interestingly, the gut flora in people suffering from a range of diseases, including diabetes, Alzheimer’s, heart disease, autism and obesity, appears markedly different from that of healthy people.

Loading the player...

What’s not certain is whether that is a cause, consequence or something in between. Either way, it makes sense that if we can restore or boost our levels of “good bacteria” by taking a probiotic supplement, we’ll reap the benefits, right?

Unfortunately, it’s not that clear-cut, according to Sydney gastroenterologist Dr Katie Ellard, of the Gastroenterological Society of Australia.

“Probiotics are a very attractive idea,” she says. “[But] the evidence that they are useful is limited. There are some small trials, using particular types of probiotics, which have shown some benefit for problems like IBS [irritable bowel syndrome], but the trials have suffered from the fact that the numbers of people studied are small and it’s hard to get an overview because different types of ‘bugs’ have been used to treat different types of gut symptoms.”

Nevertheless, many doctors and health practitioners nowadays recommend you try taking probiotics when you’re taking antibiotics, as there’s some evidence they may reduce the risk of diarrhoea.

Similarly, some studies show promise for probiotics in reducing the incidence or duration of colds and respiratory infections. People with colitis and allergies may also benefit. And, these days, probiotics are added to baby formula, too (they’re naturally present in breast milk).

Many doctors nowadays recommend you try taking probiotics when you’re taking antibiotics.

(Credit: (Image: Getty))

Yet Professor Samaras points out that the most striking results from probiotics so far – including success treating the superbug Clostridium difficile, fatty liver disease in children, obesity and chronic constipation – have been achieved through a less appetising form of probiotics than yogurts or capsules.

“The bacterial supplements given in these studies were not only prescription probiotics, but faecal transplants from healthy donors,” she explains.

The good news? Scientists hope to turn it into a pill form, with all the benefits of a full ecosystem of trillions of bacteria, as a probiotic of the future.

Until then, when you’re faced with a shelf of probiotics, rather than picking one based on brand, price or packaging, it pays to seek professional advice.

For most, including yogurt with live cultures, kefir, lassi or a probiotic drink in their diet is probably enough. Professor Samaras suggests eating an organic, natural yogurt rich in lactobacillus and bifidobacterium.

It’s worth taking a closer look before you decide on a brand. Consumer watchdog Choice says inadequate food labelling standards and pseudo-scientific names allow some manufacturers to mislead shoppers about the health benefits of probiotic drinks or yogurts.

“Probiotics are big business and with an increasing number of these products on the market, people should be more informed with better labelling that is based on robust science, not marketing spin,” says Choice spokeswoman Stephanie Baker.

Some studies show promise for probiotics in reducing the incidence or duration of colds and respiratory infections.

(Credit: (Image: Getty))

People with specific health problems may want to try supplements of a strain most likely to work for their ailment. How you take them is also important, says Dr Ellard.

“I stress that if people are trying a probiotic out, they need to take it daily, before food, for at least a month,” she says.

And while we all want to colonise our guts with health-promoting good bacteria, it’s important to note that probiotics are not suitable for everyone.

“People in ICU [intensive care units] and people with artificial heart valves or very suppressed immune systems shouldn’t take probiotics,” warns Dr Ellard.

Even for otherwise healthy people, they mightn’t always be the best option. For example, in one trial looking at the potential role of probiotics in preventing diarrhoea, Dr Ellard says “some people got bloating and increased flatulence from the probiotic”.

Given each of us harbours different ratios and types of bacteria – of which there are estimated to be between 400 and 1000 different species – it’s not surprising that what works for one person might not work for the next.

High-fibre foods, including legumes such as beans, lentils and peas contain probiotics.

(Credit: (Image: Pexels))

Yet if you’re going to introduce good bacteria to your gut through a probiotic supplement, it’s important to feed them properly, so they flourish alongside the friendly ones already living there.

This means consuming prebiotics – think high-fibre foods, including legumes, such as beans, lentils and peas, whole grains, nuts, vegetables and fruit.

Foods that are linked to overgrowth of “bad” bacteria, on the other hand, include highly processed carbohydrates and sugary or fast foods.

Maintaining a good diet is especially critical because while experts are now realising the powerful role gut bacteria play in our health, it’s still early days in figuring out how to best do something about it.

“Our health starts and ends with what we choose to put in our mouths,” is Professor Samaras’ blunt advice, “and no supplement can neutralise the junk we may choose to eat.”

Frequently asked questions

Are probiotics actually helpful?

There is no clear evidence that probiotics are beneficial. While many small studies have been conducted, there has been no standardised way to study probiotics and their effects.

Is there a downside to taking probiotics?

The most common side effects are a temporary increase in gas, bloating, constipation and thirst.

How long does it take for probiotics to work?

It takes most people between two and three weeks to feel significant benefits when they start taking probiotics.

Related stories