Probi-WHAT-tics?

Often in nutrition, certain foods are placed into the “good for us” category, and we proudly consume (and Instagram) these foods without actually knowing what they are or how they work. However, in today’s age of nutritional misinformation and health commercialisation, we must be our own advocate regarding what we place into our bodies. Although probiotics are indeed great for you, educating yourself will enable you to include the sources best suited to you in your diet (and lessen health food store confusion).

What are probiotics?

To understand what probiotics are, you must first understand that the gastrointestinal tract or “gut” is the digestive tube of your body and it is filled with trillions of microorganisms. While it might be a tad creepy to think about the fact your body is currently hosting a big bacterial party (more formally known as your microbiome), it is a completely normal and essential part of our physiology.

“Probiotics are live microorganisms that when administered in adequate amounts confer a health benefit on the host.” -WHO, 2001

This whole concept of good gut bacteria is credited to a man with a killer moustache named Eli Metchnikoff (moustache featured below). In the early 1900s, after observing Bulgarian peasants who consumed sour milk products had remarkable longevity, this guy hypothesized that modifying gut flora with the bacteria found in these fermented milk products could prevent the progression of ageing and adverse health.

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Got (fermented) milk?[/caption]

Since Metchnikoff, scientific understanding of probiotics has continually advanced. We now know there are more than 5000 strains of probiotics, which are broadly classed into the species Lactobacillus, Bifidobacterium or Saccharomyces (don’t they just roll of the tongue?). These different strains have specific functions, which exert different and combined effects on the body.

Functions and Health Benefits

Probiotics have several key mechanisms of action that enhance gut functioning and prevent intestinal disease. A systematic review published in the Annals of Nutrition and Metabolism (i.e. nutrition research gold) explains these mechanisms in beautiful, 11 page long, detail. However, to keep this probiotic crash course moving along like a high fibre diet, the findings have been summarised. Through improving the ratio of good to bad bacteria, probiotics:

• Strengthen and repair the gut barrier
• Aid the digestion of food (by increasing the acidity of the stomach)
• Have anti-inflammatory effects (from increased production of short-chain fatty acids)
• Exclude pathogens from adhering to the gut wall
• Secrete substances that attack pathogens (eg mucins, IgA & organic acids)

Given these effects, it makes sense that probiotics have been shown to prevent and treat clinical gastrointestinal disorders including diarrhoea, inflammatory bowel disease, ulcerative colitis, irritable bowel disease, and even colorectal cancer. Furthermore, emerging evidence also suggests that supporting gut health supports good health big picture.

Associations are being drawn between between gut health and everything from immune function, to mental health, to even diabetes. This idea of the gut as the epicentre of human health was described in Roman Times by Hippocrates in saying “all diseases begin in the gut.” It has also been described, much much more recently, in a TED talk by microbiome researcher Jeroen Raes, stating “if something is wrong with your gut flora, something is wrong with you.”

“All diseases begin in the gut.” -Hippocrates (460–370 BC)

But if probiotics support the gut ecosystem, and good gut health is vital for overall health, why are they not regularly promoted by GP’s or The Australian Dietary Guidelines? The problem is that research is still early days. It remains unclear regarding which strains, dosages and sources produce desired benefit, so health practitioners cannot make evidence based dietary recommendations. Despite knowledge gaps, probiotics are considered safe and no risks of use have been identified. Therefore, for the promotion of gut function, immunity and potential benefits science is only just uncovering, we should all incorporate a range of probiotic rich foods into our diets.

Food Sources & Supplements

The most popular probiotic products on the market are fermented dairy products like kefir and yoghurt. This is thought to be a consequence of dairy products being the first identified form of probiotics (you da man Metchnikoff), and consumer familiarity with yoghurtlike products as healthful foods.

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Popular probiotic dairy foods: Yakult, yoghurt & kefir[/caption]

But if the above photo of Yakult sends you spiralling into a dark 1990s lunchbox flashback, or you avoid dairy for other reasons, never fear. Fermented vegetables like sauerkraut and kimchi; fermented soybean products like miso paste and tempeh; and a fermented tea known as kombucha are also great carriers of probiotics. The science behind fermented foods is essentially the same. Bacteria convert carbohydrates into acidic compounds. With the process taking 2–7 days, the number of bacteria continually multiple to produce a food rich in probiotics.

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Other probiotic-rich foods: kombucha, miso soup, fermented veggies & tempeh[/caption]

Fermented foods are not the latest superfood scam either. Fermentation has been providing a method of food preservation and good health to many cultures throughout history. The hearsay health benefits of these foods are beginning to be substantiated by nutrition research. Kimchi, for example, is a fermented cabbage dish has accompanied every traditional Korean meal since ancient times. Research demonstrates Kimchi to contain high levels of Lactobacillus bacteria, along with various vitamins, minerals, dietary fiber, and other functional components that are amplified through fermentation.

If you want to give kimchi a go, this super simple video gives a run down of how it’s made:

[embed]https://www.youtube.com/watch?v=_kEvwNGomvg[/embed]

Another traditional probiotic food that has been scientifically analysed is Kombucha. This delicious sparkling beverage is a symbiotic culture of acetic acid bacteria and saccharomyces yeasts, containing a diverse range of probiotics. A recent review in The Journal of Medicinal Food suggests the probiotics and organic acids in kombucha result in detoxifying, antioxidant, energising and immune functions, all of which support the maintenance of good health.

Probiotics can also be obtained from various supplements. The major benefit of supplementation is that the probiotic strain and dose can be ensured, as shown in this video for Australia’s leading probiotic brand InnerHealthPlus. Strain specific dosage is important for the use of probiotics in treating intestinal disease. Furthermore, due to their large dosages, a high quality probiotic supplement may also be a desirable method of initially colonising the gut with good bacteria.

However, the isolation of nutrients from food is always a concern in nutrition. Not to mention one months supply of a high quality probiotic supplement retails between $19.95-$41.95. For the general population, food sources are more economical, more likely to be solidified as routine throughout the lifetime for lifelong benefit, and (very importantly) more delicious.

This article has hopefully provided some insight into the amazing world of gut health and probiotics. Although we don’t know everything regarding the bacteria currently inside of us, it is becoming clear they have influence over our whole body and supporting gut health is important for good health. Increasing intake of probiotics to support gut health through wholefoods is always a good idea. These foods are nutritious, delicious and contain a range of other components that benefit health. Now go out, crack open a kombucha and make Metchnikoff and his moustache proud.