Can eating too much protein backfire? UK surgeon explains how excess protein intake can negatively impact gut health

Protein is an important part of a balanced diet, but overdoing it can have adverse effects. Dr Rajan explains what happens in the gut when you consume too much.

Protein has become the star of modern diets, with many people trying to add it to every meal in the pursuit of better fitness and health. But while getting enough protein is important, more isn’t always better. This raises an important question: how much protein is too much, and what actually happens when you go overboard? As conversations around high-protein diets grow louder, experts are now taking a closer look at the potential downsides of excess intake.

Read more to find out how too much potein can impact gut health! (Unsplash)

Dr Karan Rajan, a UK-based surgeon and popular health content creator, is breaking down whether excessive protein intake can backfire and negatively affect gut health. In an Instagram video shared on March 22, he explains how protein is processed in the gut – and what happens when there’s more than the body can handle.

Can eating excess protein backfire?

According to Dr Rajan, consuming excess protein may not be ideal for gut health. He explains that while most protein is digested in the small intestine, any surplus can pass into the colon, where it is fermented by gut bacteria. This shifts fermentation away from beneficial fibres and complex carbohydrates towards proteins, leading to the production of inflammatory by-products.

The surgeon notes, “If you eat too much protein, it's not always good for your gut health. Most of the protein you eat is meant to be broken down and absorbed in the small intestine. But when your diet is excessive on the protein and fibre poor, more of that leftover protein can spill into the colon where your gut bacteria start to ferment it. So now instead of saccharolytic fermentation, where your gut bacteria ferment fibre into short-chain fatty acids, your bacteria switch modes into more proteolytic or protein fermentation.”

By products of protein fermentation

Dr Rajan notes that protein fermentation can produce harmful by-products that trigger inflammation in the colon and place stress on the gut barrier. It can also disrupt the microbiome, promoting the growth of bacterial species should ideally be present in lower amounts.

He explains, “The byproducts of protein fermentation in the colon include things like ammonia, p-cresols, indoles, phenols, and hydrogen sulfide. These metabolites are linked to a more inflammatory colonic environment and can stress the gut barrier. And you get a bacterial shift too, with more species like Bacteroides and Fusobacterium which you ideally want in lower amounts.”

Ideal protein intake

Despite the risks of excess intake, Dr Rajan emphasises that protein remains essential for overall health. However, he notes that even for athletes, the ideal intake typically ranges between 1.6 and two grams per kilogram of body weight per day.

He explains, “Now protein consumption does matter a lot. But even for athletes, evidence-based targets sit at between 1.6 and two grams per kilo per day. So if you're an 80 kilo athlete, that's between 128 g and 176 g of protein per day to pretty much maximise muscle protein synthesis, not three whole chickens and a whey intravenous drip.”

The surgeon recommends focusing on a balanced diet that includes both protein and fibre, rather than relying heavily on protein alone. He suggests choosing diverse protein sources that also provide other nutrients – such as yoghurt, lentils, and edamame – instead of repeatedly cycling through options like chicken, whey, and beef.

Dr Rajan recommends, “The real combo is protein and fibre together. Don't just limit yourself to rotating between whey, chicken, and beef like a ravenous, confused Labrador. Use more diverse protein sources like yoghurt, eggs, beans, tofu, lentils. Foods like edamame are great because they bring protein, fibre, and soy compounds like isoflavones to the party. So yes, absolutely eat enough protein. Just don't forget that your microbiome needs to be fed, too.”

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. It is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them.