Bugs in a Bottle: Friend or Hype?
He stood in the supplement aisle of a well-stocked organic market, staring at a wall of promises. Probiotics for immunity. Probiotics for stress. Probiotics for weight loss. Probiotics for replacing hair. Dozens of bottles with billions of CFUs per capsule, many costing more than a nice dinner. And yet, he couldn’t shake the question: Do these actually work?
He knew the hype. Knew the ones who generated it. And he knew the science. Probiotics – live microorganisms that confer a health benefit – have become a billion-euro industry. But most commercial formulations contain only a few species: Lactobacillus acidophilus, Bifidobacterium lactis, maybe Saccharomyces boulardii and maybe a handful of others. Helpful? Maybe. But compared to the thousands of species in the human gut, these were like repopulating a city with three types of professions.
So, as any doctor-turned-microbe-enthusiast would do, he ran a self-trial. For two weeks, he took a high-end, multi-strain probiotic with 50 billion CFUs daily. He recorded sleep, mood, digestion, stool form, and even ran shotgun metagenomic sequencing at the beginning and end.
The result? Mild improvement in bloating. No major changes in sleep or energy. The sequencing showed a transient uptick in the species consumed – but no meaningful shift in overall diversity or resilience. Within three days of stopping, those bacteria disappeared from his gut like tourists leaving a weekend Airbnb.
That matched the literature. Studies show that in healthy people, most probiotics don’t colonize – especially if the gut is already competitive. In contrast, prebiotics, fermented foods, and FMT have much deeper and more lasting effects. Probiotics are not useless – but they’re often overpromised and underdelivered.
Still, he didn’t dismiss them entirely. Certain strains – like S. boulardii for antibiotic-associated diarrhea, or L. rhamnosus GG for traveler’s gut (if no AutoBiome is available) – had real, targeted benefits. But for general health? “Probiotics,” he concluded, “are like guests at a dinner party. Polite, well-meaning… but not family.”
Next week: “I Fixed My Sleep, and My Gut Thanked Me” — how microbes and melatonin work in tandem.