As we all obsess over kombucha and kefir in an attempt to stock our gut with good bacteria, science is a few steps ahead, looking into a potential new frontier in gut health – postbiotics.
In case you missed the memo, gut health is having a serious moment, thanks mostly to the discovery of the gut-brain axis, which posits that our gut bacteria can play a significant role over our mental health.
For most of us, that’s meant eating foods that contain probiotics, which are “good” bacteria, as well as prebiotics, which are the fibres that feed said gut bacteria.
But fast forward to the future and probiotics might be ancient history as we look to postbiotics for premium gut health.
Scientists are realising that it might not be the probiotics themselves that help our gut, but rather the molecules and chemicals that they secrete — the postbiotics — that are actually of benefit to us.
Dr Paul Bertrand, head of RMIT University’s Gut Neuroscience Lab, says that while probiotics can be great for our gut health, it’s almost impossible to know which strains individuals need.
It’s meant that plenty of people have fallen victim to slick marketing campaigns promising that a particular probiotic product could hold the key to curing health woes, when the research isn’t really there.
“If we could isolate that individual chemical, we could pop that into a pill and that chemical might be a more efficient and easier way to deliver the benefit of the bacteria,” Dr Bertrand told Coach.
“It might be a drug or it might be something akin to a vitamin or it might be something else acting in the gut. It might be something those bacteria are doing to other bacteria in the gut.”
The challenge for gut scientists is that technology doesn’t currently exist to allow them to culture all of the gut bacteria, so there are thousands of strains that we know nothing about.
“The idea with postbiotics is that if we can better understand what the bacteria are doing and how they connect with the rest of the body, then we can either help it or hinder it,” Dr Bertrand says.
On top of that, Dr Bertrand says that scientists are increasingly understanding that our gut microbiome also consists of parasites, yeast, ancient single-celled organisms called archeae, and bacteriophages, which are viruses that prey on bacteria.
“They all have a lot to say about which bacteria are thriving or not because the viruses in particular prey on the bacteria,” he explains.
“It’s a whole new area of research, wondering whether the bacteriophages are in control of the bacteria.”
At present, the only way to knowingly consume postbiotics is by taking vitamin supplements that happen to be the same compounds our gut bacteria can produce – but it’s going to be a pretty haphazard approach with no guarantee of a positive health outcome.
“Bacteria make vitamins B and K, and you can take those off the shelf,” Dr Bertrand says.
Until more is discovered about postbiotics, Dr Bertrand says the best thing you can do for your gut is have a varied, high-fibre diet by eating a wide variety of grains, fruit and vegetables.
“Assuming you have a good mix of gut bacteria to start with, prebiotics will make them happy,” he explains.
“If you are eating varied fruits and vegetables and getting lots of different sorts of fibres, this is going to increase all the bacteria and give you more different types of bacteria, which has been shown to be beneficial.”
In essence, Dr Bertrand says that if you don’t have irritable bowel issues, you want to eat the opposite of a low-FODMAP diet.
“If you’re talking about feeding your microbiota, then a healthy diet has to include fibres and sugars you can’t digest,” he says.
“If you are eating refined food, the bacteria will be starving and get quite cross as they start to die. You’ll get sick and toxins will be released, which can also make your mood quite depressed.”