Do probiotic supplements help gut health?

You’ll find probiotic pills and probiotic-infused foods in almost every supermarket and pharmacy, each brimming with friendly bacteria and claims of life-enhancing benefits, from warding off colds to improving digestive health.

But are probiotic supplements really effective?

“The subject of probiotics can be confusing,” says gut expert Dr Steven Leach, Researcher and Senior Lecturer at the University of New South Wales.

A probiotic is a living microorganism that, when consumed, plays an important role in your gut.

There are thousands of types of probiotic bacteria, but the 2 most common ones are:

• Lactobacillus
• Bifidobacterium.

Our bodies have a great mix of both good and bad bacteria, but when you become unwell with a gastrointestinal illness, more bad bacteria creep in, putting your system out of balance, Dr Leach explains.

As good bacteria help eradicate the bad ones to restore balance, taking probiotic supplements, the products often claim, can therefore help improve that balance.

Dr Leach says that balancing out good and bad gut bacteria is far more complex than just picking up any old probiotic supplement from your pharmacy, as their potential benefits may only work “if you have a specific reason to take them.”

This is due to the complexity of the gut microbiome, the community of bacteria and micro-organisms that lives inside your digestive tract.

The microbiome is complex, and similar gut symptoms that present in 2 different people may be caused by completely different things. Meaning, there’s no one-size-fits-all approach to taking probiotic supplements.

There is evidence that probiotic supplements may have a potential role in preventing and treating atopic dermatitis.¹ And some research suggests that probiotics might help with mild-to-moderate ulcerative colitis (alongside conventional treatments).²

But for most people, you’re probably better off saving your money, Dr Leach says. There’s no real evidence to suggest that probiotic supplements benefit anyone who’s already in good health with a normal gastrointestinal tract.²

One exception, he adds, is “if your gut microbiome is deficient in the specific bacteria contained in the probiotic,” in which case a matching probiotic supplement “may help in the breakdown of some nutrients.”

But in the majority of cases, most probiotic supplements likely won’t contain the exact bacteria you need. Nor are you likely to know what exact bacteria you need in the first place.

Dr Leach recommends only taking probiotics if you have a specific reason to take them, such as having an illness with gastrointestinal symptoms or diarrhoea from taking a course of antibiotics.³

In any case, it’s always a good idea to speak to your doctor before taking any probiotic supplement.

“If it’s recommended to take probiotics, you may need do a bit of trial and error to find the right fit for your unique microbiome,” says Dr Leach. “But looking for a probiotic that has a specific health benefit is a good start.”

For example, one meta-analysis suggests that the probiotic strain Saccharomyces boulardii CNCM I-745 is much more effective in treating stomach bugs than C. butyricum and L. acidophilus.⁴

Or, as research suggests, those suffering from irritable bowel syndrome could benefit from taking Bifidobacterium longum 35624 or Lactobacillus plantarum CCFM8610.^{5 6}

“In most gastrointestinal illnesses your gut microbiome is likely to change and could potentially allow bad pathogenic bacteria to get a foothold in your gut,” says Dr Leach.

“Therefore, the primary health benefit in this case would be to find a probiotic that will add good bacteria to the gut and remove potential pathogens.”

According to Dr Leach, in many cases taking probiotics (such as the bacterial kinds) alongside antibiotics is not ideal, as the antibiotics will most likely just kill the probiotics.

“If you want to take a probiotic during a course of antibiotics, you should be taking a yeast probiotic, as yeast are unaffected by antibiotics,” says Dr Leach.

“You can then use a bacterial probiotic after you have completed your antibiotic course to help the recovery of the natural gut bacteria.”

If you’ve just finished your last dose of antibiotics, it’s important to talk to your doctor before taking probiotics.

While antibiotics are great for fighting off infections, they can also wipe out the good bacteria with the bad, and it can take months or even years for your gut microbiome to fully recover.⁷

Alongside a diet that includes probiotic-rich food and drinks, you can keep your gut microbiome in check by only taking antibiotics when medically necessary, Dr Leach concludes.