Researchers at Indiana University have linked a protein secreted by the stomach to obesity. In tests in mice, the team switched off the protein and found that it reduced the animals’ body fat levels, even when fed a high-fat diet.
Obesity is one of the most pressing health concerns of the modern age, increasing a person’s risk of many different diseases, such as cancer, diabetes, and cardiovascular disease. A balanced diet and regular exercise are the best treatments, but the case isn’t always that clear cut for everybody.
The makeup of the gut microbiome is a major factor, and the extent of its influence on our health is under constant investigation. In the new study, the researchers examined the effect of a particular protein, known as Gastrokine-1 (GKN1), on the microbiome.
This protein is expressed in high amounts in the stomach, and because of this researchers hypothesized that it could play a role in regulating gut microbes. To investigate, the team inhibited GKN1 in mice, then measured markers like blood sugar and insulin levels, body fat, energy expenditure and inflammation. These test animals were compared to mice that still had the functional protein.
And sure enough, the mice with GKN1 knocked out were found to weigh less, had lower levels of total body fat, and had higher percentages of lean mass than the control mice, even though they all ate the same amount of food. Even when the team put the mice on a high-fat diet, the GKN1-deficient animals resisted weight gain, body fat accumulation and liver inflammation much better than the control group.
Backing up the hypothesis that GKN1 works by influencing the gut microbiome, the team found that the test mice also had significantly lower levels of two types of gut bacteria that have previously been implicated in obesity induced by high-fat diets.
One potential problem is that lower levels of GKN1 have been linked to gastric cancer, which might be something to look out for. However, the team says that no signs of cancer – or any other ill side effects – were found in the test mice, but acknowledged that they might become more prone to the disease later in life.
The researchers also say that there’s a possibility that GKN1 deficiency is a symptom of gastric cancer, rather than a cause, so lowering it might not necessarily predispose a patient to the disease.
Clearly, more research will need to be done to investigate the relationship between GKN1 and cancer, the gut microbiome and obesity, before any human trials can begin. Nevertheless, it’s an intriguing first step towards potential treatments for obesity and its associated health problems.
The new study was published in the journal Scientific Reports.
Source: Indiana University