Bacteria which can reduce appetite in obese people and ease ‘stress eating’ is identified

Bifidobacterium longum APC1472 has potential to be a probiotic and counter type 2 diabetes, UCC researchers say

A strain of bacteria identified in UCC has potential to be used as a probiotic to reduce appetite in obese people and to ease “stress eating” associated with feeling overweight.

Known as Bifidobacterium longum APC1472, it also has huge implications for people with type 2 diabetes, notably in helping to control blood glucose, according research findings published on Friday.

Worldwide obesity has more than doubled since 1980; most of the world's population now live in countries where overweight and obesity kills more people than underweight – a trend seen in Ireland.

It is a major health challenge because it substantially increases the risk of diseases such as type 2 diabetes. In recent years, prevalence of type 2 diabetes has soared worldwide with approximately 462 million individuals affected, corresponding to 6.28 per cent of the world’s population.


A team led by Dr Harriet Schellekens at the APC Microbiome Ireland SFI Research Centre identified Bifidobacterium longum APC1472 to be an important regulator of appetite and metabolism during laboratory studies. Researchers at the centre have gone on to prove the benefit in a human clinical trial.

In a group of healthy people who were overweight or obese, their research published the Lancet journal, eBioMedicine, shows the novel bacterial strain Bifidobacterium Longum APC1472 reduced their fasting blood glucose levels and could normalise active levels of both ghrelin, a hormone signalling hunger, and the stress hormone cortisol – both of which are altered in obesity.

While no effect was seen in reducing weight gain in humans, initial research showed the bacterium reduced weight gain and fat deposit size in obese mice.

“This study shows that B. longum APC1472 has potential to be developed as a valuable probiotic supplement to reduce blood glucose, which is important in the development of conditions such as type 2 diabetes,” Dr Schellekens said.

“This study is the first of its kind demonstrating the translation of a Bifidobacterium longum species...from initial laboratory studies through pre-clinical studies to a human intervention study.”

Dr Schellekens’ lab catalogues bacteria, and uses screening techniques to identify strains that potentially can bring benefits to humans, by deploying an exhaustive “bugs to drugs” approach in developing products for incorporation into the diet.

It has been known for a long time that stress and obesity are linked, she explained. While stress can suppress appetite in the short-term, chronic stress is known to increase cortisol which increases appetite; hence the phrase “stress eating”.

“This research shows B.Longum APC1472 plays an important role in keeping our ‘hunger hormone’, ghrelin, in check, and lowers our stress hormone, cortisol,” she added – the hormone being the critical interface between “food and mood”.

This study delivers important evidence that using the strain in a probiotic supplement "can indeed be useful in the fight against obesity," said Prof John Cryan, joint senior-author of the study.

The findings reinforced the concept of the link between the gut microbiome (microbes living in the digestive tract), metabolic disease and mental health, which is a growing area of research, he added.

Prof Timothy Dinan, chief investigator on the clinical aspect of the research, said the findings are solid, but warrant further investigation of B. longum APC1472's "potential use as a psychobiotic to improve mental health".

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times