Summary: A new study identified a novel mechanism behind increased sugar intake. Researchers found that individuals living with a specific mutation, deficient in free fatty acid receptor 4 (FFAR4), have altered gut microbiota, resulting in altered gut-brain axis and food choices.
The health harms of excessive sugar intake are widespread, with some experts suggesting that sugar addiction is even more harmful than ethanol addiction. Although sugar might not have mind-altering properties like those of alcohol or illicit drugs, but it does cause signs and symptoms characteristic of addiction, like intense cravings. It also influences the brain’s reward pathways.
High sugar intake can be particularly bad when living with diabetes since it causes blood glucose spikes and contributes to insulin resistance.
For a long, researchers have been trying to understand more subtle addictions like sugar addiction. They have proposed several theories, from changes in the brain’s reward pathway to certain chemical changes in the brain. Specific metabolic changes may also play a role in this addiction.
However, in recent years, attention has shifted to the role of the gut in sugar addiction. Especially since science has realized that the gut has a greater say in the workings of the brain than it had imagined previously. It seems that the gut-brain axis can play a significant role in addiction to certain foods and sugars. Further, in recent years, researchers have proposed that changes in gut microbiota may also have a role in this addiction.
In one of the recent studies published in Nature Microbiology, researchers identified a microbe that may help reduce sugar intake.
This study was done both in diabetes-induced mice and 60 diabetes patients. In the study, researchers analyzed their blood and found that both the mice and diabetes patients were deficient in free fatty acid receptor 4 (FFAR4). This deficiency was mainly due to FFAR4 mutation.
Researchers found that those with FFAR4 mutation had greater sugar craving. They also found that low levels of this particular fatty acid significantly reduced the gut population of Bacteroides vulgatus and its key metabolite, pantothenic acid. Pantothenic acid is known to activate the GLP-1-FGF21 hormone axis, helping regulate appetite and having widespread metabolic effects.
Thus, researchers think that this specific mutation, deficiency of pantothenic acid, and reduced population of Bacteroides vulgatus resulted in increased sugar cravings.
To further confirm their hypothesis, researchers administered Bacteroides vulgatus and pantothenic acid to these diabetic mice. They found that this altered their food preferences. Thus, researchers think that they have identified a novel mechanism underlying sugar preference.
Hence, researchers propose that using probiotics containing this particular strain may have a role in modulating sugar addiction, enhancing metabolic health, and may have other health benefits.
Understanding the role of microbiota in the gut-brain axis is quite complex. Nevertheless, an increasing number of studies show that gut microbiota has a greater say in this axis than thought earlier.
Surely, these changes in gut microbiota may occur for various reasons, like genetics, the use of medications, and certain food choices.
There are many ways of altering gut microbiota, too. Thus, using probiotics is just one of the ways. Other ways are lifestyle and dietary changes.
Finally, it is quite likely that there are many other mechanisms playing a role in sugar addiction. In the future, researchers may discover other microbial species playing a role in metabolic health and sugar preference.
Source:
Zhang, T., Wang, W., Li, J., Ye, X., Wang, Z., Cui, S., Shen, S., Liang, X., Chen, Y. Q., & Zhu, S. (2025). Free fatty acid receptor 4 modulates dietary sugar preference via the gut microbiota. Nature Microbiology, 1–14. https://doi.org/10.1038/s41564-024-01902-8
