UK surgeon explains the effects of eating too much protein and not enough fibre: ‘Don’t want that happening too often’
Protein is one of the most important macronutrients that the body needs. However, it is definitely not the only one that one needs to focus on. Loading up on protein while not consuming sufficient fibre can actually have negative effects on gut health, according to Dr Karan Rajan, a UK-based surgeon and health content creator. Taking to Instagram on May 8, he elaborated on the subject.
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What happens when one eats excess protein?
Proteins are made up of amino acids. When one eats excess protein, the extra, mostly undigested, amino acids reach the large intestine, where they undergo fermentation. This is not beneficial for gut health.
As Dr Rajan explained, “When you eat protein, most of it gets absorbed in your small intestine. But when your protein intake is very high, especially from animal sources, excess amino acids enter the large intestine undigested, and your gut bacteria ferment them.”
The process is called proteolytic fermentation, and it produces metabolites like ammonia, hydrogen sulfide and phenols like priol. “These compounds in excess can impact the gut barrier, and repeated exposure over time can cause low-grade inflammation, which can change the cells lining the colon, and you don’t want that happening too often,” cautioned Dr Rajan.
Diets that are loaded with animal protein, particularly those that have saturated fat, can also increase bile flow into the gut. The gut bacteria then convert the primary bile acids to secondary bile acids, which is again not good for health, shared the surgeon.
How does eating more fibre help?
According to Dr Rajan, fibre is what makes the consumption of excess protein safer.
“When fibre is present and being fermented, your gut bacteria produce short-chain fatty acids, which actually lower the gut pH and suppress protein fermentation. Fibre essentially competes against protein for bacterial attention and wins,” he explained. Thus, the issue is not eating too much protein; it is not balancing protein with sufficient fibre.
“You don’t have to cut out meat, but just consider subbing in the occasional plant-forward protein sources. Beans, lentils, edamame, split peas,” shared Dr Rajan. “Feel free to protein-max, but make sure you fibre-max at the same time.”
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