In crime movies and series, we usually see someone who wants to get rid of a corpse by dissolving it in acid. What we think less often is that the acids in our stomach, mainly hydrochloric acid, are much more powerful. The pH of these acids is between 1.5 and 3, similar to that of car battery acid, and can dissolve metal if given enough time. Fortunately, the stomach lining protects it from damage.
This extreme acidity is essential. Not only does it allow us to break down most of the foods we eat, but it also eliminates many harmful bacteria. Yet heartburn gets a bad rap.
Heartburn or heartburn is a very unpleasant sensation of pain or burning in the esophagus. Under normal conditions, the sphincter that separates the stomach from the esophagus should contract to prevent stomach acid from escaping, but if it relaxes for any reason, as usually happens when swallowing, or because we have eaten a lot, reflux occurs: the contents of the stomach, mixed with stomach acid, return to the esophagus.
Reflux can be prevented by chewing well and avoiding binge eating or going to bed on a full stomach. Additionally, it helps to identify the foods that most commonly trigger it and eliminate them from your diet. But instead of prevention, many people choose to take a pill to reduce stomach acid.
Antacids or baking soda are chemical bases that neutralize acid and produce gas. On the contrary, proton pump inhibitors (PPIs) like omeprazole go further, because they reduce the production of acid in the stomach.
Reflux can be prevented by chewing well and avoiding binge eating or going to bed on a full stomach. In addition, it helps to identify the foods that most frequently trigger it and eliminate them from the diet.
PPIs such as omeprazole work by inactivating an enzyme called H+/K+ ATPase, also known as the “proton pump,” which is responsible for producing hydrogen ions (protons) to form hydrochloric acid in the stomach. Because the inhibited enzyme cannot regenerate, it takes 24 to 48 hours for the stomach to produce acid again, which is how long the effect lasts after a single dose.
Gastroesophageal reflux affects 16% of the population, according to the Spanish Society of Digestive Pathology (SEPD), and PPIs are the main treatment to relieve irritation and inflammation. They are also useful in the treatment of gastric and duodenal ulcers, as they give the stomach a break so that the lesions can heal.
Finally, they are used to prevent long-term ulcers induced by the use of nonsteroidal anti-inflammatory drugs (NSAIDs), as these drugs can increase the risk of gastric lesions. This is why omeprazole is wrongly considered a “stomach protector” that will defend us from the damage caused by a fabada followed by a square of ribs.
A 2023 study estimates that 25% of the world’s population uses proton pump inhibitors. However, this popularity has also led to an increase in its inappropriate use, especially long-term and without medical indication, since it is a drug sold without a prescription.
“Apart from pathological cases such as gastroesophageal reflux, stomach ulcers or functional dyspepsia, there are ways to regulate the pH of the stomach without resorting to medication, such as adapting the diet,” explains Arnau Vich Vila, PhD in biology, a researcher at the University of Lubiana in Belgium. Vich is the author of several studies on the influence of medications such as omeprazole on the intestinal microbiota.
Apart from pathological cases such as gastroesophageal reflux, stomach ulcers or functional dyspepsia, there are ways to regulate the pH of the stomach without resorting to medication, such as adapting the diet.
Arnau Vich-Vila
— doctor of biology
Omeprazole Abuse and Your Gut Bacteria
PPIs such as omeprazole are generally safe when used short-term and under medical supervision, but taking them consistently and without prolonged or inappropriate use can pose several health risks. One of the most documented problems is that they interfere with the absorption of nutrients, particularly magnesium, calcium, and vitamin B12, which require acidity to be assimilated. This leads to a higher risk of bone fractures, especially in older adults due to a lack of calcium, kidney damage due to a lack of magnesium, and even neurological problems due to a lack of vitamin B12.
But acid is not only necessary for digestion, it protects us from infections. “Stomach acid acts as a barrier that separates bacteria normally found in the mouth from those found in the intestine. By reducing this acidity, certain bacterial species of the genus Streptococcus either Rothiawhich are normally in the mouth [y que se eliminan en el estómago]they can pass into the intestine.
One of these bacteria is the famous Clostridium difficileresponsible for severe diarrhea. The use of proton pump inhibitors increases the risk of infection by C. difficult from 18% among hospitalized patients who do not take them to 24% of those who do.
“In vitro tests have shown that proton pump inhibitors can have an antibiotic effect, i.e. inhibit the growth of bacteria that make up the healthy intestinal microbiota,” adds Arnau Vich. That is, “the reduction of beneficial bacteria and the increase of opportunistic bacteria, such as Enterobacteria.” What are Enterobacteria? Some of them are well known, such as Salmonella either Escherichia coli.
Omeprazole also comes out
An altered gut microbiota, which is called dysbiosis when it is negative, can be the cause of many diseases, such as colon cancer. “There is a lot of scientific evidence to suggest that certain bacteria can promote inflammatory bowel disease and some types of colorectal cancer,” Vich warns. “But not all alterations of the gut microbiota are dysbiosis. Dysbiosis looks like the most extreme cases, especially when there is inflammation.”
In vitro tests have shown that proton pump inhibitors can have an antibiotic effect, i.e. inhibit the growth of bacteria that make up the healthy intestinal microbiota.
Arnau Vich
— doctor of biology
The question is whether the altered microbiota is the cause of diseases due to inflammation or whether it is a symptom. “In some cases, it is a question of cause and effect. For example, in inflammatory bowel disease, we see that the microbiota can induce inflammation, but at the same time inflammation can induce changes in the microbiota,” Vich says. “When we talk about deviations, we are talking about a very strong reduction in the bacterial community, but also in the richness and diversity of bacteria.” In experiments on rats, long-term administration of PPIs changed the composition of their gut bacteria, which began to resemble those of rats fed a high-fat diet.
Diet is the biggest determinant of microbiome health, especially when ultra-processed foods are eliminated and fiber in the form of vegetables and fruits is increased. “We see this at the population level. People who have a better diet tend to have a better microbiome,” Vich says.
Experiments suggest that we cannot “fix” our gut microbiota by taking probiotics or changing our diet for a while and then going back to what we were before, but that for the positive effects to be lasting, we need to change the way we eat. In turn, a better diet can prevent the need for omeprazole. A recent study showed that switching to a Mediterranean diet was a better option for preventing reflux.
* Darío Pescador is editor and director of the Quo Magazine and author of the book the best of yourself Published by Oberon.
