A warning has been issued over a common drug used by Brits to relieve heartburn and acid reflux. An expert has revealed that it can have a harmful long-term impact on gut health and digestion.

Deborah Grayson, dubbed the ‘Godmother of Pharmacology’, took to TikTok to discuss the impact of omeprazole, which is a proton pump inhibitor (PPI). She shared a video under her handle @tgopharm, which has over 42,000 views, and said the drug can lead to a number of issues. They include bloating, nausea, weight gain and vitamin deficiencies.

According to the Daily Mail, the NHS prescribed 73 million PPIs in England in 2022-23, costing around £190 million. It is one of the most prescribed medications across the nation.

Mrs Grayson, who has been working as a pharmacist for 30 years, and also runs Practice With Confidence, teaching transformative patient care, said: “Omeprazole stops heartburn and reflux, but how does it really work? It’s a PPI, and that interferes with the cells of the stomach responsible for producing stomach acid.

“So, if we stop the stomach from producing acid – by taking a PPI – the theory is that we will stop the acid coming back into the oesophagus and causing heartburn and reflux.

“There’s often a discussion about whether heartburn is related to low or high stomach acid. But actually it’s to do with the timing of the stomach acid.

“While stopping your stomach producing that acid can be beneficial in the short term, it’s not always great for your digestion in the longer term as we need that acid to break down our food.

“It can be helpful to have omeprazole if you’ve got gastritis or erosion in your oesophagus, but if you’ve only got simple heartburn-related problems, longer term it can have greater impacts on the body.”

Acid reflux often causes heartburn and can be triggered by stress, excess weight, eating too quickly or consuming alcohol, caffeine and chocolate. While it can be uncomfortable, stomach acid is needed for digestion and protects against harmful microbes in food.

Mrs Grayson said low stomach acid may increase infection risk. It can also hinder absorption of key nutrients like Vitamin B12, iron, calcium and magnesium.

She said: “Long-term use of PPIs can significantly impair digestion. Stomach acid plays a crucial role in breaking down food, particularly proteins, and activating enzymes like pepsin.

“When acid levels are too low, food may not be properly digested, leading to symptoms such as bloating, nausea, abdominal discomfort, and IBS-like issues including flatulence, constipation, or diarrhoea.

“Poor digestion may also contribute to nutrient malabsorption, potentially leading to fatigue or weight fluctuations.

“Reduced stomach acid can also compromise the gut’s natural defense barrier, increasing susceptibility to infections such as Clostridium difficile, Campylobacter and small intestinal bacterial overgrowth (SIBO).

“These can cause further gastrointestinal symptoms and, in some cases, serious complications.”

In a previous video, Mrs Grayson said lifestyle changes can help make a difference against acid reflux and heartburn. This includes taking the time to eat slowly.

She explained: “Think about what you are going to have, how it tastes and how it smells. This can trigger the anticipatory response in the same way that preparing it yourself would have done.

“Modern lifestyles have resulted in many people deciding they are hungry, dashing into the nearest food outlet and eating food within minutes. ‘This means that the body has to play catch up, exacerbating symptoms.”

She also advises people to avoid certain foods, including peppermint, chocolate, coffee, citrus and tomatoes. People can also leave a gap between eating and sleep, as lying down with a full stomach can trigger reflux.