Christmas is a time of excess — swigging mulled wine, unbuttoning bursting buttons and wishing in hindsight that you hadn’t been so greedy. But why not spare a thought for your industrious gut microbes, who are like busy elves frantically dealing with the onslaught of your festive indulgences, grumbling as they work overtime in breaking down an overload of rich food and booze, and starved of the high-fibre foods that they rely on.
These healthy bacteria live in your gut in the hundreds of trillions, outnumbering your body’s cells 10 to one and weighing about 2kg — about the same as two bags of Brussels sprouts. This complex community of thousands of species is known as the gut microbiome and improving its health is considered the new frontier of personalised nutrition.
Research is increasingly showing the calamitous consequences of forgetting about these invisible friends, which are linked with disease and weight gain, and a multitude of benefits of keeping them in good health. These gut bacteria help us to extract energy and nutrients from food, while making essential vitamins and immune molecules that we just can’t make on our own. They may even keep us happy by producing key brain chemicals like serotonin.
Gut microbes are sensitive beings, and the duration of traditional Christmas indulgence of low-fibre and rich high-fat foods can wreak havoc on your gut bacteria diversity. When they are deprived of fibre, certain species take over and nibble away at your gut lining, which is fine for a short while — but if overdone causes problems and inflammation. As well as fibre your microbes thrive on polyphenol-rich foods, fermented foods with live microbes and a diverse diet. So here are a few festive tips you can use to help your microbes survive until the New Year without breaking too much with tradition.
For nibbles, use plenty of mixed nuts and olives rather than crisps or other processed snacks. These are good sources of fibre as well as polyphenols, which microbes thrive on as an energy source and convert into immune protective chemicals. For alcohol, wine-based drinks are the best, with red wine being the top rated for polyphenol content and microbial food. White wine and champagnes also do pretty well followed by beer — particularly the yeasty varieties and many stronger Belgian beers. Spirits, sadly, are poor sources of polyphenols. If you are feeling adventurous, seek out some kombucha (fermented tea) which you can also drink as a weak beer or make your own punch with ginger.
For your starter, think of warming vegetable soups with spices and added crème fraiche, or some smoked salmon on wholegrain toast with pickled relishes. Pickles can be a great source of live microbes (probiotics) if fermented naturally and not with vinegar. Sauerkraut is a good example as well as Korean kimchi if you like it spicy. Rather than just using boiled red cabbage for your main course, why not ferment your own for three days beforehand, mixing it with salty water to get the microbes working to break down the fibre as well as apples, mustard, fennel and garlic and anything else you want to throw in.
Don’t boil your Brussels sprouts — instead try cooking them slowly in garlic and olive oil (other great sources of polyphenols). Cook your potatoes, or sweet potatoes, with the skins on and before putting them in the oven coat them in olive oil (it has to be extra virgin to be any good). At the same time add as many other root veg — turnips, parsnips, carrots — as you can. You can even be adventurous and try something new and exciting for your microbes like kohlrabi, an ugly but great-tasting vegetable.
A cheese platter is a must. Try and pick new, traditional varieties you haven’t tasted before, ideally unpasteurised cheeses from Britain and France. There are plenty now to savour from small producers. Include those with a nice rind full of microbes or blue streaks that contain tasty fungi — these are part of the healthy gut community and are believed to be good for the immune system. Make sure you leave them at room temperature for several hours so the microbes wake up and bring out the full flavour.
There’s not much you can do health-wise with the Christmas pud, except perhaps serve small portions with a big dollop of full-fat yoghurt (and optional lemon zest) with live microbes rather than the usual cream. Then, as you slump to the sofa, try and force down some healthy chocolate – go for dark chocolate with 70 per cent-plus cocoa, which is packed with polyphenols. For your hot non-alcoholic beverage, coffee is the microbial favourite, followed by green tea.
If you survive till Boxing Day, start with another hit of black coffee and a shot of fermented milk (called kefir), perhaps mixed with berries, which has five times the number of live microbes as yoghurt. Then allow your gut a chance to recuperate and give your microbes a much-needed day off. Enjoy.
Tim Spector is professor of genetics at King’s College London and author of The Diet Myth: The Real Science Behind What We Eat