The past decade has seen the rise and rise of the gut-health trend, forging an industry worth an estimated 19.12 billion USD in 2024, with a projected annual growth rate of 3%, according to market insight firm, Statista. It's safe to say then that the gut health trend is here to stay and new research, linking bad gut health with obesity, will only serve to strengthen it.
How is bad gut bacteria linked to obesity?
A new study, carried out by an international team of researchers and presented at the Federation of European Neuroscience Societies (FENS), has identified certain gut bacteria linked to the development of food addiction in both mice and humans. This in turn can lead to obesity. Additionally, and even more pertinent for the gut health industry, the team identified bacteria that have a protective effect against food addiction.
“A number of factors contribute to food addiction, which is characterised by loss of control over food intake and is associated with obesity, other eating disorders and alterations in the composition of bacteria in the gut microbiome,” said Elena Martín-García, Professor at the Laboratory of Neuropharmacology-NeuroPhar in the Department of Medicine and Life Sciences at the Universitat Pompeu Fabra, Spain. “Until now, the mechanisms underlying this behavioural disorder were largely unknown.”
Professor Martín-García used the Yale Food Addiction Scale (YFAS 2.0) to diagnose food addiction in mice and humans. The scale contains 35 questions for humans to answer, and these can also be grouped into three criteria for use in mice - persistent food-seeking, high motivation to obtain food, and compulsive behaviour.
She and her colleagues investigated the gut bacteria in mice who were and were not addicted to food, finding an increase in bacteria belonging to a group called the Proteobacteria phylum and a decrease in bacteria belonging to the Actinobacteria phylum in the food-addicted mice. These mice also had a decrease in the amount of another type of bacteria called Blautia from the Bacillota phylum.
The researchers then used the Yale Food Addiction Scale to classify 88 human patients into those who were addicted and those who were not addicted to food. Similar to the findings in mice, decreases in Actinobacteria phylum and Blautia were seen in those who were food-addicted, and increases in Proteobacteria phylum. Further analyses by the team showed how the findings in humans correlated with those in mice.
“The findings in both mice and humans suggested that specific microbiota could be protective in preventing food addiction,” said Professor Martín-García. “In particular, the strong similarities in the amount of Blautia underlined the potential beneficial effects of this particular gut bacteria. Therefore, we investigated the protective effects of oral administration of lactulose and rhamnose, which are non-digestible carbohydrates known as ‘prebiotics’ that can increase the amount of Blautia in the gut.
"We did this in mice, and found that it led to an increase in the abundance of Blautia in mice faeces, in parallel with dramatic improvements in food addiction. We saw similar improvements when we gave the mice a species of Blautia called Blautia wexlerae orally as a probiotic. The gut microbiota signatures in both mice and humans suggest possible non-beneficial effects of bacteria belonging to the Proteobacteria phylum and potential protective effects of increasing the abundance of Actinobacterial and Bacillota against the development of food addiction.”
What is the gut microbiota?
Each of us has trillions of microbes, or bacteria, living in our gut. These are collectively referred to as the gut microbiota, or gut microbiome. The two most common species of helpful bacteria found in our gut microbiota are Lactobacillus and Bifidobacteria. Maintaining a healthy balance between the helpful (good) bacteria and the unhelpful (bad) bacteria is fundamental in supporting a healthy digestive system, with the gut now understood to be central to health, containing more than 70% of our immune system.
How can the gut health industry use the results of this research?
This could be hugely beneficial for food and beverage manufacturers within the gut health space as they could formulate gut health products specifically for people who struggle with food addiction.
“These results from our study may allow us to identify new biomarkers for food addiction and, most importantly, to evaluate whether the beneficial bacteria could be used as potential new treatments for this obesity-related behaviour, which, at present, lacks any effective therapeutic approaches,” said Professor Rafael Maldonado, while addressing the FENS. “Potential new treatments could involve using beneficial bacteria and dietary supplementation.”
What are prebiotics in food?
Prebiotics in food are compounds which support the beneficial microorganisms or good bacteria in the gut (gastrointestinal tract).
Dietary prebiotics are typically nondigestible fibre compounds that pass undigested through the upper part of the gastrointestinal tract, supporting the growth of the ‘good’ bacteria in the colon. Prebiotics were first identified and named by academic researcher Marcel Roberfroid in 1995. Prebiotics can be found in a multitude of foods, including almonds, bananas, wholegrain wheat, corn, rye and barley, and flaxseeds
What are probiotics in food?
Probiotics in foods are live microorganisms often described as helpful or ‘good’ bacteria because they help keep your gut healthy. Probiotics are available in foods such as live yogurt.
The first probiotic, Lactobacillus bulgaricus, was discovered by Bulgarian physician and microbiologist Stamen Grigorov in 1905.
Discover more about gut health on our dedicated gut health page
Source: Gut microbiota signatures of vulnerability to food addiction in mice and humans
Published online: 26 June 2024
DOI: 10.1136/gutjnl-2023-331445
Authors: Solveiga Samulėnaitė, Alejandra García-Blanco, Jordi Mayneris-Perxachs et al.
