Source: The Guardian
Want a healthy gut? Reach for the kimchi, sauerkraut, artichokes, coffee and chocolate. But watch out – one category of food will make your microbes wither.
Kimchi, kombucha, sauerkraut, miso and kefir – all fermented foods and drinks – have been around for centuries, but suddenly they are all the rage. The reason? They are supposedly packed full of gut-healthy microorganisms, and we are finally waking up to just how much the trillions of microorganisms that live in our guts (AKA the gut microbiome) contribute to our mental and physical health.
True, probiotic products such as Yakult – sweetened skimmed milk fermented with a single strain of friendly bacteria – have been shifting hefty units for some time: the global probiotic market, dominated by yoghurt drinks, was worth $45.6bn (£33bn) last year. But Yakult is fairly bland and sweet. Traditional and home-fermented delicacies are another, more pungent matter altogether: kombucha (a naturally fizzy cocktail of green tea and sugar) tastes vinegary; kimchi (vegetables fermented Korean-style) is sour and fiery; sauerkraut, which is fermented cabbage, whiffs of sulphur. All can intimidate palates used to highly processed western blandness.
Because of how they are prepared, they all contain microorganisms that boost the diversity of good bacteria, yeasts and fungi living in our guts. Harbouring a flourishing gut flora has been linked to lower obesity, fewer autoimmune conditions and digestion problems, longer lifespan, good brain function and happiness.
Some very big companies are beginning to take this on board. If you could never quite trust the mouldering kombucha you once nurtured in your airing cupboard, now you can buy some from Whole Foods instead. Step forward brands such as Eaten Alive, Bio-tiful – whose flavoured version of the fermented-milk drink kefir is now stocked in Sainsbury’s – and the Urban Fermentary, whose bacteria-riddled pickles and drinks come in appetising packaging. (It is unlikely, however, that mass-produced, pasturised ferments will contain as many of the desired microorganisms as those made using traditional methods, so it’s worth checking how a product was made before you buy.)
Take sauerkraut, the pickled cabbage beloved of central Europeans. Unlike the majority of supermarket-bought pickles, which are preserved in vinegar and have no “live” element, the cabbage in sauerkraut is massaged in salt until the juices are drawn out and the healthy microorganisms living on it produce lactic acid. This stops it going off, while adding a vinegary twang. The result, says Tim Spector, professor of genetic epidemiology at King’s College London, where he also directs the British Gut microbiome project, is “a really good combination of a pro- and prebiotic”. Spector’s 2015 book, The Diet Myth, revealed that much of what we eat is digested by our microbes, which in turn produce vitamins and unlock other nutrients for us (and are influential in many other ways). As with live yoghurt, the probiotics are the friendly bacteria food contains, whereas prebiotic is the word for substances that feed your gut flora. “The cabbage actually feeds other microbes in your gut, so I’m definitely a fan of kraut, kimchi, all those kind of things.”
But unless you are fermenting foods yourself, these products are not cheap – a 375g jar of sauerkraut from Eaten Alive will set you back £6. It’s good to know, therefore, that bog-standard live yoghurts aren’t a total waste of time. All yoghurt is fermented and the milk used to make products for sale is legally required to be pasteurised to kill off pathogens, after which a few strains of lab-produced friendly bacteria are added. “We’ve done some [not-yet-published] research ourselves,” says Spector, “showing that [this] yoghurt definitely does have an effect on the microbes.” The added bacteria aren’t the same as the ones that live in our guts, he says. “The [former] are moving through the body, but they can have an effect on your existing microbes and we also know they produce substances that are beneficial. So, in a way, they’re energising your gut microbes as they go through, producing some chemicals that look as if they’re good for weight loss as well.” However, he reserves the title of “super yoghurt” for kefir. “It has about five times as many microbes, with more diversity, and also has extra fungi in there and they’re all good.”
Read the full article here: https://getpocket.com/explore/item/magical-microbes-how-to-feed-your-gut
