The Dark Side of Probiotics: Not All Are as Good as They Seem
The marketing has convinced us that probiotics are always a good idea. They are present in yogurts, fermented drinks, and even in chocolates, promising to strengthen digestive health. However, a new study in mice suggests that some of these bacteria may have the opposite effect than expected. Could they be harming our bodies without us knowing? Science is starting to sound the alarm.
### Not all probiotics play on the same team
Researchers from North Carolina State University have analyzed how two strains of, considered common probiotics, act. By administering Lactobacillus gasseri Lg-36 and Lactobacillus acidophilus to mice, they discovered that their effects were radically opposed to Clostridium difficile, a pathogenic bacterium responsible for serious intestinal infections.
The L. gasseri competes directly for resources with C. difficile, preventing it from growing. On the other hand, L. acidophilus favors this bacterium by releasing amino acids that serve as food. In other words, one strain protects and the other aggravates the problem.
### Probiotics: digestive miracle or disguised risk?
that, in theory, provide benefits to the intestinal microbiota. But this study shows that not all probiotics can be assumed to be equally useful. In reality, their effects may depend on the specific species and strain, the intestinal environment… and even the presence of pathogenic bacteria.
The finding casts doubt on the label “probiotic” as synonymous with “good for health.” If this is confirmed in humans, many products promoted as healthy would have to be reevaluated.
### Deceptive advertising and the bacterial placebo effect
The rise of functional food marketing has turned probiotics into a . Bacteria are added to ultra-processed products, with the promise of turning them into healthy options. However, without a rigorous analysis of the type of bacteria, these strategies could be more harmful than beneficial.
Furthermore, there is a risk that consumers blindly trust these products, believing that they help their digestive health when they could be worsening certain conditions.
### Conclusion: more science, fewer labels
Although the study was conducted in mice, it sends a clear message: we must stop treating probiotics as a uniform category and start differentiating them based on their real effects. Not all benefit the body, and some could be feeding our worst intestinal enemies. The next time you read “contains probiotics” on a package, you may want to look beyond the advertising claim.
