Binge drinking alters gut microbiome linked to behavioural changes – Irish scientists find

‘Most common pattern of alcohol misuse during early adulthood linked with gut microbiome alterations, even before addiction develops’

Youth binge drinkers show alterations in the gut microbiome which may be linked to poor ability to recognise emotions and cravings to consume alcohol, Irish scientists have found.

In a study of binge drinking habits of young people conducted by researchers at APC Microbiome Ireland based at UCC, they found significant alterations in microorganisms that live in the human digestive system and affect health.

It demonstrated that alterations in the microbiome were associated with poor ability to recognise emotions and the urge to consume alcohol. Binge drinking can have short and long-term impacts on health and wellbeing, their study concludes.

Published in The Lancet eBioMedicine on Thursday the findings provide further evidence that the gut microbiome appears to regulate brain functioning and emotional functioning.


Binge drinking is the most common pattern of alcohol misuse during adolescence in Western counties. One in three young Europeans engage in frequent binge drinking. In Ireland, 60 per cent of 18- to 24-year-olds report binge drinking on a monthly basis.

It is associated with increased risk of developing alcohol use disorder and experiencing cognitive alterations which may persist into adulthood.

The study of 71 young people investigated the potential link between the gut microbiome and social cognition, impulsivity and craving in young binge drinkers.

“Binge drinking was associated with distinct microbiome alterations and emotional recognition difficulties. Associations were found for several microbiome species linked to with emotional processing and impulsivity,” said Dr Carina Carbia, a postdoctoral in the laboratory of Profs John Cryan and Ted Dinan at APC Microbiome Ireland.

Researchers found a strong link with cravings and alterations in microbiome composition and neuroactive potential over time.

These findings could help the development of novel dietary or pre/probiotic interventions directed at improving early alcohol-related microbiota and cognitive alterations in young drinkers during the vulnerability period of adolescence.

The study builds on growing evidence in animal models that the microbiome is an important regulator of social and emotional cognition and extends it to human subjects.

Dr Carbia added: “By focusing on young adults, at a crucial time of both brain and gut-immune development, we identified gut microbiome alterations linked to binge drinking in young people. The microbiome composition showed associations with social cognition and impulsivity, adding support to the growing evidence that the gut microbiome plays a key role in brain and behaviour.”

Changes in the gut microbiome composition and “the neuroactive potential” were associated with higher craving over time, “constituting interesting candidates for early biomarkers of dependence”, she said.

Alcohol misuse

Prof Cryan said it demonstrated the most common pattern of alcohol misuse during early adulthood is linked with gut microbiome alterations, even before an addiction develops.

“Furthermore, it highlights the importance of the gut microbiome in regulating craving, social cognition and emotional functioning. The findings support the development of microbiota-targeted diets or interventions to positively modulate gut-brain communication during this vulnerable period of adolescence before an addiction develops,” he suggested.

The study at the Science Foundation Ireland research centre received funding from the EU Horizon 2020 research and innovation programme.

Kevin O'Sullivan

Kevin O'Sullivan

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