Trendy probiotics do NOT work says mcrobiologist

Taking probiotic supplements has become extremely popular in recent years.

They are said to keep your gut and digestion healthy by replacing the ‘bad’ bacteria with ‘good’ bacteria.

However, now a distinguished microbiologist has spoken out to warn not enough of this ‘friendly’ bacteria – such as Lactobacillus acidophilus – from supplements make it to your gut to kill harmful bacteria – such as Bifidobacteria.

Research has linked our gut health to a range of conditions including obesity, depression, multiple sclerosis and rheumatoid arthritis – explaining why the global probiotics market is set to exceed $63 billion in five years.

But Ian Orme, professor of microbiology and pathology at Colorado State University, insists it’s based on dodgy science.

An expert has suggested probiotics are a waste of money as they do not provide enough ‘friendly’ bacteria to replace the ‘bad’ bacteria in the gut

‘Thirty billion Lactobacillus sounds good, but after going through the stomach acid, only about 43 of them survive,’ he told Business Insider. 

‘In other words these 43 or so bacteria politely ask the million or so anaerobic Bifidobacteria to please leave,’ said Orme. ‘Yeah, sure.’ 

But now synbiotics are set to be all the rage. These combine a probiotic bacterial strain with what’s called prebiotics, which actually feed and increase the friendly bacteria in your gut. 

Killed by stomach acid 

Studies have backed up the notion that probiotics are ‘perishable’ bacteria.

Heat and stomach acid can kill them, rendering them ineffective before they’ve even been digested.

A study published last year by the University of Copenhagen found no difference in the gut bacteria between participants who were taking probiotic supplements and others who weren’t.

The had team looked at the results of seven trials of the products – often sold as milk-based drinks, biscuits, sachets, or capsules. 

Another study published in April by the University of Toronto found probiotic yoghurt didn’t contain enough beneficial bacteria to offer the health benefits seen in clinical trials. 

Yet there is plenty of research over the years that supports the health benefits of probiotics. 

An animal study published in The American Journal of Pathology in July found that probiotics may prevent and treat fatty liver disease and keep it from advancing to liver cancer.

What are synbiotics?  

The concept is that the pre- and pro-biotics work together to provide a combined benefit – while the probiotic settles in and pushes out the ‘bad’ bacteria, the prebiotic hangs around and feeds the growth of positive strains.

Just this month, as part of the first large-scale clinical trial of its kind, researchers discovered newborns in rural India who were given a synbiotic were at a substantially lower risk of developing the deadly infection sepsis.  

Their risk was found to drop by 40 per cent in the study of 4,000 infants by the University of Nebraska Medical Center College of Public Health. 

Smaller studies have suggested that synbiotics could have beneficial effects on obesity and diabetes.


Researchers now estimate that a typical human body is made up of about 30 trillion human cells and 39 trillion bacteria.

These are key in harvesting energy from our food, regulating our immune function, and keeping the lining of our gut healthy.

Interest in, and knowledge about, the microbiota has recently exploded as we now recognise just how essential they are to our health.

A healthy, balanced microbiome helps us break down foods, protects us from infection, trains our immune system and manufactures vitamins, such as K and B12.

It also sends signals to our brain that can affect mood, anxiety and appetite.

Imbalances in the gut are increasingly being linked to a range of conditions. Last year, scientists at California Institute of Technology found the first ever link between the gut and Parkinson’s symptoms.

The composition of our gut microbiota is partly determined by our genes but can also be influenced by lifestyle factors such as our diet, alcohol intake and exercise, as well as medications.