Probiotics, once the savior of reluctant antibiotic takers everywhere, it looks like probiotics are not the magic solution to restoring healthy gut bacteria in humans. Unless we are in the minority of the population who has the genes to process them, studies have found that probiotics are pointless at best and damaging at worst. Also, the only way to find out if we’ve been wasting our money or not is to take an invasive test only available in Israel.
So how did we get the question so badly wrong? After all that: probiotics are highly encouraged after a script of antibiotics. Because it turns out, the current method of “gut bacteria” testing (taking fecal samples) is flawed—as a study conducted by immunologist Eran Elinav of the Weizmann Institute of Science in Israel has just shown.
“Probiotics are living microorganisms that are taken by millions of people to boost their microbiome or restore their gut ecosystem after a dose of antibiotics. Yet questions remain about whether they work (New Scientist).”
To discover what happens when we take probiotics, the team of Israeli scientists has sampled the microbiome of healthy volunteers directly using endoscopies and colonoscopies with previous microbiome research has relied on “indirect” stool samples. They fed 15 of the subjects after that, either a commercially available a placebo or probiotic. The direct method of testing this led to the discovery that the microbes found in feces were not representative of those that had colonized the gut.
“Relying on fecal samples as an indicator of what goes on inside the gut is inaccurate and wrong.”
The research also revealed that, although probiotics colonize a lucky few’s gastrointestinal tracts, most people’s gut micro-biome straight up expels them. The “invasive” method of testing is the single way to tell this, as both colonized and non colonized guts produce similar stool samples. From this, they concluded that probiotic colonization patterns are “highly dependent” on the individual concerned, and the idea that everyone can benefit from a universal probiotic is total, “Empirically wrong.”
“Some people accept probiotics in the gut, while others pass them from one end to “another.
The researchers observed what happens to the microbiome of people. These are the people who take probiotics after a given course of antibiotics, which they had been prescribed. Twenty-one volunteers took a similar course of antibiotics and were assigned to one of three groups. The first group’s microbiome was rested to recover by itself, whereas the number second group was prescribed probiotics. The third group was given a dose of their original pre-antibiotic microbiome by a fecal microbiota transplant.
Probiotic bacteria successfully colonized the gut of everybody in the second group. Which must be good, right? Wrong. In an unexpected twist, this “potently and persistently” prevented the return of the person’s healthy microbiome for up to 6 months. “This was very alarming and surprising to us. The adverse effect has not been described to date,” said Elinav.
The most effective and best way to restore a person’s healthy gut bacteria was to give them a dose of their pre-antibiotic microbiome via FMT (fecal microbiota transplant). In these volunteers, the gut microbiome returned to normal within days.
Earlier studies have found a link between prolonged disruption and obesity, allergies, and inflammation. “It’s potentially harmful,” said Elinav.
The conclusion? Probiotics aren’t necessarily worth their weight in dollars, and to be sufficient, their formula needs to be highly tailored to the individual. And in severe gut cases disruption, an FMT is a better option.