Why does starting high-fibre diet cause gas and bloating? UK surgeon explains fibre-flatulence curve

Increasing fibre intake from a low baseline often causes gas and bloating. But that should not dissuade an individual from continuing the diet, shares Dr Rajan.

Fibre is one of the most important macronutrients that aids in digestion and bowel movement. However, increasing the fibre content in the regular diet for the first time often results in gas and bloating in individuals.

Taking to Instagram on April 25, Dr Karan Rajan, a UK-based surgeon and health content creator, explained why that happens, and why one should go through it deliberately to make things better.

Effects of increasing fibre in regular diet

To explain the link between fibre and gas and bloating, Dr Rajan mentioned the fibre flatulence curve.

“When you start at a very low fibre baseline, there's a good chance you experience very little flatulence, not because your gut is healthy, but because there's very little activity in your microbiome,” he stated.

The reason for less gas being produced by the gut at the time is that there is very little fibre that the healthy gut bacteria get to ferment.

“Then you start increasing fibre. Suddenly, you're experiencing more gas and bloating because now your gut bacteria are being made to work hard, and they are not used to this new workload,” explained Dr Rajan. “The fermentation and breakdown of fibre is less efficient, more intense, and more gas is produced.”

With time and consistent high intake of fibre, one reaches the top of the curve. It can be uncomfortable, but that is not a sign that fibre is bad for health. It simply means that the body is adapting to processing the nutrient, shared the surgeon.

Improving efficiency of gut bacteria…

“If you slowly keep going and consistently eat more fibre, you're exerting an evolutionary pressure on your gut bacteria,” explained Dr Rajan. “They adapt to this pressure in response to the increased amount of fibre you're feeding them.”

The amount of fibre-digesting enzymes produced by the gut bacteria increases as they become more efficient at breaking down fibre. Over time, it leads to less production of gas and more of short-chain fatty acids.

In Dr Rajan’s words, “Eventually, you pass the peak of the curve and enter fibre-maxing territory. And for the same level of fibre intake, it's suddenly not so gas-provoking. Your gut bacteria are producing a greater volume of short-chain fatty acids instead of excessive gas.” It signals that the individual’s fibre training is complete.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.

This report is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them.