Should you drink kefir every day? A dietitian explains the benefits and how much to drink

In terms of foods that come with with big health claims, kefir is up there with the most talked about.

Over the last year, searches for 'kefir drink' have risen 105% on Ocado, while Sainsbury's reports searches for 'plain kefir' on its site have doubled in the same period.

While a daily glass or bowl of kefir might seem like a new health trend, it's been part of some cultures' diets for hundreds of years.

But is there good reason for all the hype, and could it actually improve our health?

Evidence for health benefits is still emerging, but regular consumption could support gut health as well as contributing to your intake of nutrients like calcium and protein.

For most healthy adults, including kefir in your diet each day can be part of a balanced lifestyle.

Given the nickname 'the Champagne of dairy' for its gentle fizz, 'kefir' usually refers to a fermented milk drink, although it comes in spoonable, yoghurt-like consistencies too. (Water kefir varieties are also available.)

It's traditionally made using kefir grains, which resemble tiny cauliflower florets. These grains contain a mixture of beneficial microbes, like good bacteria and yeasts. They're added to milk and, as the mixture ferments, it thickens and becomes tangy and slightly fizzy.

Like with other fermented foods, external, the live microbes in kefir are linked to good health. In particular, it's said to support gut health, digestion, immunity, metabolism and even mental wellbeing.

But not all kefir is created equal. Some brands might have less density and diversity of bacteria than others, because of the manufacturing process – so it's worth picking carefully.

Kefir is up there with some of the most extensively studied fermented foods. A recent scientific review of 28 clinical studies, external looked at whether it could improve two areas: metabolic health (measured by looking at cholesterol, blood sugar and blood pressure) and gut health.

The results? Kefir was linked to improvements in cholesterol levels, blood pressure and even body composition – although findings weren't consistent and studies often only involved small numbers of participants.

In terms of gut health, there was evidence it helped relieve constipation and some studies reported it reduced certain markers of inflammation.

There were even positive signs for people who struggle with lactose intolerance. Drinking kefir seemed to result in fewer gut symptoms than drinking milk, because the fermentation process reduces the lactose content while the microbes may also help with digestion.

While these findings are optimistic, scientists still aren't 100% certain about kefir's health benefits. This is because, so far, studies have been small and there are lots of variables – from the quantity consumed to the type of kefir used. And not all studies have found positive effects.

For now though, the evidence is promising – especially when it comes to gut health. And microbes aside, it's a nutrient-dense addition to your diet. A 250ml serving has 9g protein and 300mg of calcium (over 40% of the UK adult's recommended daily amount).

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Kefir comes in plain and fruit flavoured varieties. The thickness and tanginess vary quite a bit, with some producers smoothing out the fizz, so it's worth trying a few to see which ones you like.

Kefir works brilliantly anywhere you'd usually use yoghurt. So, for example, use it in smoothies (try this kefir raspberry cooler or just blend it with frozen berries), serve it with fruit or pour it over granola or muesli.

Plain kefir works as a cooling, tangy topping for chilli, curries and soups too, and it can be turned into a salad dressing by whisking with olive oil, lemon and a little seasoning.

Kefir isn't a miracle food, and drinking it won't offset a poor diet. But it could be a useful addition to healthy eating habits.

If you're new to fermented foods, have irritable bowel syndrome (IBS), or a sensitive gut, it's best to start with a small amount and build up gradually.

This gives your digestive system time to adjust to it. Start with around 100ml a day and gradually work up to a glass (250ml) if you enjoy it.

Remember, it's all about consistency if you want the biggest impact on your gut microbiome, so building a small daily habit with kefir will likely be more beneficial than having it occasionally.

And, if you are focusing on gut health, enjoy kefir alongside a healthy, balanced plant-rich diet that includes plenty of high-fibre foods, rather than relying on any single food alone.

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