While the plant-based revolution might have reduced the amount of lactose in our diets, certain dairy-based foods are making a comeback in the name of good health, and kefir is one of them.

I used to think of kefir as one of those slightly icky health foods - probably incredibly good for you but mildly gross. Fermented yogurt? Not the sexiest foodstuff. So despite it being recommended by nutritionists, I eschewed kefir and opted for trendier foods and drinks like kombucha and kimchi instead.

These other fermented foods were at least a step in the right direction, especially as new research suggests the health of our guts could be responsible for any number of complaints and maladies. One recent study found that the cure for clinical depression might lie in gut regulation, and another suggested we might sleep better if our gut bacteria were more stable.

Foods and drinks that contain gut-friendly bacteria hold a lot of power and we're only just beginning to realise just how essential good gut health is for better long-term wellbeing. Nevertheless, a growing interest in the gut has led to a marketing boost for gut-friendly foods and, once again, kefir has appeared on my radar.

"Kefir is a cousin to yoghurt - the main difference being it contains more different strains of microbes. It's been around for thousands of years yet it's the rise in gut health over the last few years that has brought it back in vogue," explains Dr Megan Rossi, who goes by The Gut Health Doctor.

Dr Rossi continues: "While there are limited clinical trials looking at the specific benefits, mechanistically it's thought to have added benefits to yoghurt given its high strain diversity and bacteria count. These include benefits with weight management, heart disease, plus a new study from Stanford University showed a high intake of fermented foods was linked with lower markers of inflammation."

One of the things I've become obsessed with in recent years is decreasing inflammation in my body and rolling back my biological age. I'm no Bryan Johnson, but I like to think I've done a pretty good job of this - a recent health scan showed my body's age to be five years younger than my actual age. So, given the reported health benefits of kefir and the fact that I was seeing it absolutely everywhere, I decided to give it a go.

I drank kefir, which is high in natural probiotics like lacto and bifido bacterium, every day for 30 days, sipping two different brands in a variety of flavours - I tried natural kefir, kefir with added protein, honey and orange blossom kefir and strawberry to name but a few variations. Not only did I shock myself by absolutely loving the taste, I also loved the results. I had more energy, I felt fuller for longer after meals, my problematic hormonal skin looked better and I found myself looking forward to my morning glass. The skin might have been a red herring, but I was still pleased with how things were going.

Dr Rossi recommends consuming 100-200mls of kefir daily, depending on the individual, and your desired outcome also dictates when you should drink it.

If you're drinking it to aid digestion and improve your gut health, drinking it on an empty stomach is recommended. However, if you're drinking it as a snack or to improve satiety, after meals is the best time to have it. I opted for 100mls and drank it in the mornings before my breakfast.

At this point, my morning routine is pretty detailed, what with all the other health drinks and supplements I take - I have water with electrolytes, a vanilla protein bone broth drink and a coffee with collagen powder, mushroom powder and MCT oil - so adding a small glass of kefir into the mix wasn't a tall order.

At first I felt a little unsettled by the pale yogurt-like liquid and the smell of it. I didn't really enjoy the way it coated my tongue and it made the back of my throat feel unpleasant - they always say you should avoid dairy before public speaking for this exact reason.

On one occasion I went to a health appointment and was asked to stick out my tongue. I panicked, thinking it would look weird because of all the kefir I'd drunk that morning - luckily I was told I had a very healthy-looking tongue.

Of course, some people struggle more with just the slightly bizarre sensation of consuming a thick dairy drink. Those with dairy allergies should avoid dairy-based kefir and despite the fact that it contains low levels of lactose, those who are lactose intolerant should probably give it a miss too.

"You can get water kefir and dairy kefir," Dr Rossi explains. "Dairy kefir is made with milk and contains lactose, unlike water kefir which is made with sugary water. Generally speaking, homemade dairy kefir is thought to contain around 30 per cent less lactose as the fermentation process reduces some of the lactose present in standard milk."

If you want to avoid dairy altogether then water kefir is probably the way to go. Like kefir made from milk, it comes in a variety of forms and flavours and is suitable for vegans. Dr Rossi also adds that if you are immunocompromised or receiving cancer treatment it's not advised to make your own kefir at home, whether water or milk based, given the risk of contamination.

Rather than making my own or drinking water kefir, I drank dairy Kefir from Biotiful and Bio&Me. Having tried plenty of other brands for my research into the best gut health drinks, these two were my favourites in terms of flavour, consistency and price.

When it comes to separating a good quality kefir from a poorer quality one, Rossi recommends looking at the ingredient list. "Sadly many brands are now adding sugars in the form of fruit extracts, versus using whole fruit, and others including new protein products have added sugar in the form of sucrose in them," she explains. "Many brands also include thickeners like pectin, which are unnecessary if you get the fermentation technique correct."

I've continued to drink a small glass of kefir each morning and it feels as though it's doing me good. A 2022 paper from the National Library of Medicine suggests that in several studies, kefir has been shown to, "antagonise pathogens, reduce proinflammatory cytokine production, contribute to cytotoxicity of tumour cell lines and reduce tumour burden, and improve serum glycemic and lipid profiles." This is high praise for a seemingly straightforward fermented drink.

It's higher in protein than milk or traditional yogurt - Greek yogurt offers more protein per gram - and easy to get hold of as most supermarkets stock at least one brand and there are plenty to be found online.

With gut health set to be one of the hottest topics in health and wellbeing this year, there's certainly no harm in trying kefir. The bacteria in a single serving could potentially support better digestion, improved immunity and lower inflammation in the body. Despite my initial hesitance to try it, I'm now a kefir convert and love the stuff.

I drank kefir for a month and it made me feel like a superhuman