Fermentation up close and personal

Last week, I wrote about  feeding your microbiome well. The verdict was that eating hearty fibres, called prebiotics, and foods that contain good living bacterial cultures, called probiotics, can contribute to good gut health! While scientists still don’t know much about which specific species bacteria are the most important, it seems that incorporating some probiotics into our diet is a good idea.

This week I thought I’d check in on the probiotic status of some popular fermented foods.

I took a look at Health Canada’s standard for a food to be considered a probiotic and did some research into what types of probiotics have clinical evidence to support their health benefits. I was looking for three things in my determination of how probiotic a particular food is:

1. Is it fermented with Lactic Acid Bacteria?

Lactic Acid Bacteria (LAB) is a very broad category of bacteria that are well known for having a positive effect on our gut health. These guys talk to our good bacteria, fend off the bad bacteria, and make a happy ecosystem in our gut.

There are lots of  other bacteria that do good things for our gut, but the majority of the research has been done on the beneficial properties of LABs, so we’ll use that as our yardstick.

2. Does it contain enough LABs?

Not only do we want LABs, but we want lots of them! For a food to be considered a probiotic in the Canada, it must have at least one billion bacterial cells per serving, so that was my criteria for quantity.

3. Are its LABs living?

Some preservation or preparation techniques can kill off beneficial bacteria. We need these bad boys alive and well to do their job!

Which foods pass the test? Let’s dive into it!

Yogurt

Until recently, I thought probiotics only existed in yogurt (I thank the Activia commercials for that). It’s true: yogurt is among one the most popular bacteria-containing foods in the western world.

Yogurts, as well as kefir and fermented buttermilk, are full of LABs! Even vegan yogurts contain LABs!

The other great thing about yogurt is that there is that the colonies of bacteria are substantial. All commercial yogurt in Canada contains live bacteria, and they all seem to stay alive even until the end of the yogurt’s shelf-life (happily, even frozen yogurts contain live cultures).

So does yogurt pass the probiotic test? YES

Yogurt bonus benefits:

The bacteria in yogurt also produce and release the enzyme (cellular machine) that breaks down lactose. People who are lactose intolerant are lacking this enzyme, but since it is present in the bacteria, yogurt is more tolerated by people with lactose intolerance than other dairy products. Those LABs just want to make sure everyone can enjoy some TCBY every once and a while!

Kimchi

Kimchi is also fermented by LABs, and most kimchis contain a good concentration of these hardworking bugs.

As for the live bacteria in kimchi, you have to be careful. Some store-bought kimchis are thermally stabilized, which means the bacteria have been killed off in order to increase the shelf life of the product. If you really want the probiotic benefits of kimchi, buy it fresh or make your own.

Does kimchi pass the probiotic test? MOST OF THE TIME

Kimchi bonus benefits:

Kimchi is made fermented cabbage, radish, and seasonings, which are rich in dietary fibre, vitamin C, and other minerals. So not only do you get the probiotic benefits of Kimchi, but you get the bonus of nutritious veggies as well!

Sauerkraut

Sauerkraut is another type of fermented cabbage. Pretty much everything about kimchi holds true for sauerkraut, minus the presence of radish (unless you decided to put radish in your sauerkraut). Again, fresh is best to ensure you’re getting live cultures.

Does sauerkraut pass the probiotic test? MOST OF THE TIME

Kombucha

Kombucha strays a little bit from the norm in terms of fermented health foods. It’s made from a specialized yeast culture. The bacteria that grow in kombucha are also different—most of them are acetic acid producing (that’s just vinegar!). There is a much smaller quantity of LAB in kombucha, but, depending on your batch of ‘booch, may still be enough for you to get enough microbes to make your gut happy.

Does kombucha pass the probiotic test? SOME OF THE TIME

Kombucha not-so-bonus benefits

There are a lot of claims about kombucha that don’t have any science to back them up. Websites, blogs, and kombucha brands claim this bubbly drink has anti-cancer, anti-obesity, and anti-aging properties. None of these claims are supported!

Cheese

Ah, yes, the beloved cheese. I’ve got great news for you cheese fanatics—some cheeses contain living LABs! Okay, only a few. In a survey that compiled all the information on the microbial profile of cheeses that have been done around the world, there were more than 30 types of cheese that contain LABs. Unfortunately, not many of these have enough LABs to pass my test.

The one well-known cheese that passed with flying colours was Camembert. Bring on the baguettes!

Does it cheese pass the probiotic test? CAMAMBERT DOES

Camembert not-so-bonus benefits

The probiotics in Camambert come at a cost—this gooey, moist cheese also contains a ton of sodium, very little fibre, and a substantial amount of saturated fats. If you want your probiotics to come in a holistically nutritious package, I’d stick with Kimchi. So much for that baguette.

Miso

There is very little information on the composition of bacteria in miso, a fermented soy bean paste. There is likely very little to no LABs in miso paste. On top of that, bacteria die when it’s too hot. So, if you are cooking with miso there is little chance there will be any living bacteria left.

Does miso pass the probiotic test? PROBABLY NOT

Sour Beer

Sour beers are made with LABs! Wouldn’t it be great if we could get all of our probiotics from beer? Unfortunately, the quantity in sour beers that have been analyzed is too low to be considered a probiotic source. But there have only been about five different beers from two different breweries that have been analyzed for the presence of LABs, so you can still hold out hope for this one!

Does it sour beer pass the probiotic test? UNFORTUNATELY NOT

Sourdough

Sourdough bread doesn’t contain any living organisms—the hot over temperatures kills off the bacteria. But sourdough starting cultures often contain LABs.

Does sourdough pass the probiotic test? NOT AT ALL

Sourdough potential bonus benefits

LABs have another trick up their sleeve—they produce an enzyme that breaks down phytates. Phytates are molecules that hold on to minerals like iron and magnesium, making them harder to absorb into our bloodstream. If the cultures in sourdough break down the phytates, then we absorb more nutrients from our bread!

It turns out that the LABs in sourdough aren’t very good at doing this—yet. Scientists are trying to engineer bacterial cultures in order to increase the amount of phytates they break down, so that we could make nutrients in our food more available.

The Verdict

While measuring LAB content of a food is a good starting off point to determine it’s probiotic-ness, when it comes to understranding probiotics, there is so much left to learn! Consuming LABs is positively correlated to our gut health but that definitely isn’t the whole picture. There are good bacteria that don’t fall into the LAB category, and there are some LABs that may be more damaging to us than good! Scientists are still trying to decode which bacterium play the biggest role in improving our gut health.

My biggest takeaway is that while probiotics are a great supplement to a healthy diet, it’s more important to foster a happy environment for the microbes that are already in your gut: eating whole grains, fruits and vegetables with lots of fibre are going to make the biggest difference when it comes to feeding your gut well.