Probiotics: bloated stomach, fogged head

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

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Metabolism, immune defense and even emotional life: intestinal bacteria have an enormous influence on people and their health. This is impressively shown by a flood of studies over the past few years. In order to have a positive influence on their own microbiome, more and more healthy people are now taking so-called probiotics. They contain living, health-promoting microorganisms such as lactic acid bacteria. But that can have drastic side effects.

Researcher around Dr. Satish Rao from Augusta University recruited 38 patients who, despite inconspicuous medical findings, suffered from a chronic, inexplicable gas, stomach ache with pain, feelings of tension and intestinal winds.

Confused, unfocused, forgetful

30 of them also had cognitive problems such as mental confusion, impaired judgment, poor short-term memory and difficulty concentrating. In English-speaking countries, this phenomenon is known as "brain fogginess".

The mental problems occurred mainly after meals and then lasted between 30 minutes and several hours. In some of the participants, they were so pronounced that those affected could no longer do their jobs. All 30 participants with "brain fog" were taking probiotics. Of the eight study participants without cognitive problems, only one took probiotics.

Massive bacterial colonization in the intestine

With the help of bacterial cultures, the researchers were able to check whether massive intestinal germs had settled in the test subjects' small intestine. This was the case for every second participant with “brain fog”. In the test subjects without cognitive problems, this only applied to one in four.

In particular, the researchers found large amounts of lactic acid bacteria in the small intestine, which metabolize the simple sugar glucose to form D-lactic acidosis. D-lactic acidosis is temporarily toxic to brain cells. Some participants with "brain fog" symptoms had levels of D-lactic acidosis three times higher than usual.

In addition, 76 percent of those affected by the “brain fog” suffered from hyperacidity of tissue and blood due to lactate (lactic acidosis). It was only 30 percent of the cognitively unimpaired participants.

Antibiotics for the brain

Following these examinations, the participants discontinued the probiotics with “brain fogginess”. They also received antibiotics that reduced intestinal bacteria. In many cases, the gastrointestinal complaints such as abdominal pain and cramps subsided. In addition, cognitive problems completely disappeared in 85 percent of the participants. In some cases, the others improved significantly. "Now that we know the problem, we can deal with it," says Rao.

In the eight participants without cognitive impairments, at least four had massive bacterial accumulations in their intestines. They too received antibiotics. This also improved gastrointestinal symptoms such as abdominal pain, cramps and gas.

"Probiotics are of great help when it comes to rebuilding the intestinal flora, for example after antibiotic therapy," says study leader Rao. As a dietary supplement for healthy people, however, they should be consumed with caution.

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