While I waited at the pharmacy to collect my prescription, I couldn’t help but be drawn to the large display of probiotics prominently featured on the counter. It reminded me of my research frenzy from two years ago, as I eagerly gathered information about microbiomes and probiotics to prepare for writing my book, The Microbiome: What Everyone Needs to Know.
After days of immersing myself in probiotics, the brightly packaged products before me caught my eye and sparked my curiosity.
Their sleek packaging had bold claims: “Supporting gut health” and “Friendly bacteria.”
As I was about to receive antibiotics for my tonsillitis, I wondered if I should also consider probiotics to help replenish the beneficial gut bacteria that antibiotics might eliminate.
The pharmacist, who recognized me both as a local GP and as someone he had just examined, nodded encouragingly and gestured toward the products.
“These are very popular,” he noted.
Turning the box over, I examined the contents. It claimed to contain thirty capsules, each packed with 5 billion live cultures to be taken daily.
I compared it to others available, noting dosages ranging from 2 billion to 25 billion bacteria per capsule. Such a wide range made me question the safety of these dosages.
The descriptions of live cultures were ambiguous, labeled variously as “trusted” or “friendly.” Some higher-dose brands labelled themselves as “diverse” or “powerful,” sounding less like supplements and more like corporate products.
Regarding their functions, the messaging became even less clear. Probiotics were said to “complement your natural gut bacteria” or enhance “your everyday life.”
While the pharmacist took some time to prepare my medications, I continued reading the small print.
Each brand confidently claimed resilience against stomach acid and heavily promoted their research backing—terms like “most researched live culture” and “highly researched strains” abounded. Yet, the absence of specific efficacy claims left me puzzled.
Eventually, I found a list of ingredients detailing various combinations of bacteria, some featuring up to 15 distinct types, consistently including several varieties of lactobacilli and bifidobacteria.
Lactobacillus acidophilus is well-known for its role in yogurt production, while Bifidobacteria are frequently used in the food industry. Together, they constitute about 12% of our typical gut flora.
Why, then, do probiotic products seem to revolve around the same bacterial species? And why are their claims always so intentionally vague?
Approximately 5% of adults take probiotics, with a tendency for higher education levels, income, and dietary habits among them. Would a better understanding of microbes change our willingness to use probiotics?
We naturally ingest a vast number of bacteria in our food. On an average day, we consume around 1.3 billion bacteria, even when eating freshly washed or cooked items.
Once in the stomach, most bacteria face the high acidity, which damages or kills them. Only a few survive to reach the colon, and those probiotics that do tend to remain for only a short time.
Taking a probiotic capsule packed with 25 billion bacteria introduces a microbial load significantly higher than our typical intake. Even “friendly” probiotic strains can cause serious infections if they enter the bloodstream.
Fortunately, most individuals can handle this significant microbial influx due to their immune systems. However, those with weakened immune systems should steer clear of probiotics, as they may be at a higher risk of infections.
The consistency in the bacterial strains across probiotic brands stems from their recognition as safe, with many having been used in the food industry since before 1958. If a microbe is classified as “Generally Recognized As Safe,” no additional research is required. By making general efficacy claims, producers can avoid proving their effectiveness altogether.
allowfullscreen=”allowfullscreen” frameborder=”0″>Despite the lack of efficacy claims, the probiotic industry effectively conveys a positive image, and as I held the box in my hands, I felt an urge to believe that it was beneficial for my health.
“Do you want these as well?” the pharmacist asked, breaking my train of thought.
As I checked the price—£17.99 for 30 low-dose probiotic capsules, something I could get from my regular diet—I ultimately decided to stick with just the antibiotic for £9.90.
Related: Probiotics vs Prebiotics: What’s The Difference And Do You Need Both?
So, do probiotics actually work?
I’ve learned to tread lightly when asked this question. Many who inquire—often with enthusiasm—already believe in the concept and usually take them. To avoid disappointing anyone, I typically respond, “Well, they probably haven’t done you any harm.”
Although there’s always a price to pay.
Berenice Langdon, Senior Lecturer and Honorary Consultant, St George’s, University of London
This article is republished from The Conversation under a Creative Commons license. Read the original article.
