Researchers found that the combination of antibiotics and a typically Western diet, which is high in fat, multiplies the risk of chronic inflammatory bowel disease. Irritable bowel patients in particular should definitely eat healthy and low-fat.
Fat and antibiotics increase risk of intestinal diseases
More and more people are affected by chronic inflammatory bowel diseases (Crohn’s disease, ulcerative colitis). The specific causes are not known. However, a 2011 study on antibiotic side effects, found that patients with inflammatory bowel disease had taken antibiotics in the years prior to their onset, while healthy controls had not.
Another study on this topic was published in July 2020 (in the Cell Host and Microbe journal ). Researchers at the University of California, Davis, found that it is not just antibiotic doses that increase the risk of inflammatory bowel disease, but that a typical Western high-fat diet can further increase the harmful potential of antibiotics ( 1, 2 ).
Fat and antibiotics paralyze mitochondria
The combination of an unhealthy high-fat diet and antibiotics can apparently paralyze the mitochondria in the cells of the intestinal mucosa, which leads to inflammatory processes there and can promote the development of chronic inflammatory bowel disease (IBD) or its precursors.
The mitochondria are tiny power plants in the cells. They generate the energy that we need to live, energy that is required for every single metabolic process.
Irritable bowel patients are particularly affected
Particularly affected by this increased risk of IBD are people who already suffer from irritable bowel syndrome, which applies to 11 percent of the world’s population. With irritable bowel syndrome, you repeatedly suffer from phases with abdominal pain, flatulence, diarrhea or constipation. If the intestinal mucosa becomes inflamed and the intestinal flora changes in an unfavourable way, this is referred to as a precursor to IBD.
The study involved 43 healthy adults and 49 IBS patients. 19 of the irritable bowel patients had elevated calprotectin levels in their stool. Calprotectin is a marker for intestinal inflammation. Anyone who has an elevated calprotectin value is considered to be affected by a preliminary stage of IBD.
Fat and antibiotics: the risk of intestinal diseases increases eightfold
Looking at the dietary habits of the study participants, it was found that those who ate a high-fat diet had a 2.8 times higher risk of suffering from pre-IBD than participants who ate a low-fat diet. Those who took antibiotics had a 3.9-fold increased risk of developing IBD.
However, people eating a high-fat diet and taking antibiotics at the same time were 8.6 times more likely to be among the 19 pre-IBD cases than participants who ate a low-fat diet and were not on antibiotic therapy.
“Anyone who had to undergo antibiotic therapy in the past and also had a high-fat diet had the highest risk of developing IBD precursors,” explained Andreas Bäumler, Professor of Medical Microbiology and Immunology and leader of the study. “Until now we have not taken such risk factors into account sufficiently.”
How antibiotics and fat sabotage your cells
A high-fat diet actually seems to cooperate with antibiotics. Together they sabotage the work of the mitochondria in the cells of the intestinal mucosa and prevent them from generating energy from glucose and oxygen. The cell’s oxygen consumption decreases, which causes the excess oxygen to escape into the intestines.
However, most beneficial gut bacteria thrive best in a low-oxygen environment. If the oxygen content in the intestine now increases, this leads to a change in the intestinal environment and, as a result, to a change in the composition of the intestinal flora. From now on, those bacteria that are more oxygen tolerant will predominate. These, in turn, are considered harmful and pro-inflammatory microbes, which it is better not to have in excess in the intestine, as they can lead to the aforementioned IBD precursor.
It is better to avoid antibiotics and fat – and build up the intestinal flora
So if you want a healthy gut, you’d better avoid the very things that harmful gut bacteria love. So avoid high-fat foods and avoid taking antibiotics whenever possible!
Remember: If antibiotics are unavoidable, always take probiotics to protect the intestinal flora!
Note: Since there are very different high-fat diets, we would like to point out that the study is about the typical western diet, which is known to be extremely high in carbohydrates, so that it may be the combination of a lot of fat and a lot of sugar/white flour, which (particularly under the influence of antibiotics) led to the observed deterioration in the intestinal environment. The study was not about low-carb or ketogenic diets.