While browsing the supplement aisle recently, I was struck by the sheer number of probiotic products — many of them marketed with vague claims like “supports general health.” It’s a timely reminder that probiotics are often misunderstood and misrepresented, both by consumers and marketers.
What Are Probiotics?
Probiotics are live microorganisms — typically bacteria or yeast — that, when consumed in adequate amounts, can provide health benefits. Our gut is home to trillions of microbes that play essential roles in:
- Immune function
- Vitamin production
- Metabolism
- Nutrient absorption
- Gut barrier integrity
A diverse microbiome is generally associated with better health outcomes. Conversely, a less diverse or imbalanced microbiome (dysbiosis) is linked to a range of adverse health markers.
The Problem with “General Health” Claims
Many probiotic supplements are sold in capsule or tablet form and marketed as beneficial for “general wellbeing.” But these broad claims are rarely supported by robust clinical evidence. Most probiotics don’t produce lasting changes in the gut microbiome, and any effects are typically short-lived.
When Probiotics Do Help
There is solid evidence for the use of specific probiotic strains in targeted clinical scenarios. But the key word here is specific. The benefits of probiotics are strain-dependent and indication-specific. Examples include:
- Antibiotic-associated diarrhoea
- Respiratory tract infections
- Genital thrush
- Irritable bowel syndrome (IBS)
- Iron absorption
- Bone density support
For instance, the strain Lactobacillus plantarum 299V has been shown to increase iron absorption — by approximately 20% from food and up to 50% from supplements. However, this strain is often expensive, typically costing over $1 per daily dose.
A Case of Misleading Labelling
Recently, I came across a Swiss iron + probiotic supplement priced at just $20 — which initially seemed promising. But on closer inspection, the probiotic strain included was not 299V, and there’s no evidence that it improves iron absorption. This is a classic example of misleading marketing: pairing iron with a generic probiotic and implying enhanced absorption without supporting data.
Takeaway for Patients and Practitioners
Probiotics can be valuable — but only when the right strain is used for the right condition, ideally backed by randomised controlled trials. Be wary of generic claims and always check the strain and evidence before investing in a supplement. probiotics, gut health, microbiome, evidence-based medicine, supplements, iron absorption, IBS, antibiotic-associated diarrhoea, functional medicine, endocrine health