Is A Vegan, Vegetarian, Or Omnivore Diet Best For Your Gut?

If you’re taking part in Veganuary this month, you’re not alone ― an impressive 3% of the UK population was up for trying the scheme in 2023, YouGov says.

You may also be trying a vegetarian lifestyle in January, or giving meat-free Mondays a go. 

All diets can be good for us if they’re well-balanced, though the British Nutrition Foundation notes “Vegetarian diets are generally higher in fruit, vegetables, whole grains, and fibre and lower in saturated fat and sugar” than those which include meat. 

And now, a study from gut health company ZOE has sought to find which of the three benefits our microbiome most. 

And?

It’s important to note that dietary studies are usually observational, which means researchers don’t intervene and, say, feed a lifelong vegetarian meat they otherwise wouldn’t eat. This is one such study.

That means you can’t always do something like a double-blind controlled trial, so you can only find associations; as a result, you can’t prove one factor causes a certain result. You can only establish a link.

Take vegetarianism, for instance. The British Nutrition Foundation says “vegetarians are likely to be more physically active, drink less alcohol and are less likely to smoke. This may explain some of the health benefits” we mentioned earlier. 

Still, ZOE’s study, published today in the journal Nature, found that omnivore, vegan and vegetarian diets were each associated with their own gut bacteria profiles.

Vegan diets were associated with more beneficial gut bacteria while red meat eaters showed higher levels of bacteria linked with inflammation, poorer cardiometabolic health and species linked to an increased risk of colon cancer and inflammatory bowel disease.

Vegetarians did not have as many harmful bacteria as those who ate red meat but dairy had its own effect on the gut.  

After looking at data from over 21,000 participants, it seemed that on average, people with vegan diets consumed more plants overall, which helped their guts.

“This study underscores how important diet is in shaping the gut microbiome and our overall health,” Professor Tim Spector, co-founder of ZOE, said in a press release.

“We found that a plant-rich diet, particularly one high in a variety of fruits and vegetables, leads to a healthier microbiome composition, which is important for better health outcomes in the long run, including a reduced risk of chronic diseases.”

Does that mean my gut is doomed if I eat meat?

No. This study found that certain foods may have their own unique impact on your gut’s microbiome.

But it also suggested that the more plants you eat, the happier your gut is ― vegetarians and vegans ate a lot of the fibre and vitamin-rich goodies.

Nor does “plant-based” strictly mean vegetarian or vegan.

The study’s press release reads: ”[the paper] indicates the possibility that individuals following mixed diets (omnivores) could share gut microbial signatures with plant-based eaters, particularly if they incorporate similar amounts of plant-based foods into their diets.” 

“However, the results also show that mixed-diet individuals tend to consume significantly fewer healthy plant-based foods than vegetarians or vegans, potentially limiting the microbiome benefits seen in those groups.” 

In other words, whatever your diet is, try to get more plants in! Your gut will thank you.