Mice are not the only ones whose weight is influenced by the fungi in their gut. In fact, a new study suggests that the fungal microbiome may play a role in human obesity as well.
The study, published in the journal Nature, found that obese people have a different mix of gut fungi than people of normal weight. What’s more, when the obese people lost weight, their gut fungi changed, too.
The findings add to a growing body of evidence linking the microbiome—the collection of microbes that live in our bodies—to a host of health problems, including obesity.
Previous research has shown that the gut microbiota of obese people is different than that of people of normal weight. But it’s not clear whether those differences are a cause or consequence of obesity.
The new study, led by researchers at the University of Aberdeen in Scotland, set out to answer that question.
The researchers first compared the gut fungi of two groups of people: those who were obese and those of normal weight. They found that the obese people had lower levels of certain types of fungi and higher levels of others.
Next, the researchers looked at how the gut fungi changed when the obese people lost weight. They found that the changes in gut fungi were linked to changes in weight.
Specifically, the obese people who lost the most weight had the greatest changes in their gut fungi. And those changes were associated with increased levels of a type of bacteria known to be linked to weight loss.
“Our findings suggest that the gut fungi may play a role in human obesity, and that changes in gut fungi may be involved in the process of weight loss,” said study co-author Ruth E. Ley, a professor of ecology and evolutionary biology at Cornell University.
The findings are preliminary and more research is needed to confirm the results. But if the link between gut fungi and weight is real, it could have important implications for the treatment of obesity.
“If we can identify the specific types of fungi that are linked to obesity, it may be possible to develop probiotic or other therapies that target those fungi,” Ley said.
Scientists have known for some time that the composition of the gut microbiome – the collection of all the microbes that live in the gastrointestinal tract – can influence weight gain or loss. Now, a new study in mice suggests that the particular mix of fungi living in the gut may also play a role in regulating body fat.
The study, published in the journal Science, found that when mice were given a low-fat diet, they lost less weight if their gut contained a greater diversity of fungi. In contrast, when the animals were given a high-fat diet, they gained less weight if their gut contained fewer types of fungi.
Interestingly, the study also found that the effects of the gut fungi on body weight were independent of the overall number of microbes living in the gut. This suggests that it is the specific mix of fungi, rather than the overall amount of microbes, that is important for regulating body fat.
The findings add to a growing body of evidence linking the gut microbiome to a variety of health conditions, including obesity. Although the study was conducted in mice, the authors say the results are likely to be relevant to humans, as the gut fungi of mice and humans are known to be quite similar.
Further studies are needed to confirm the role of gut fungi in regulating body weight in humans, but the findings suggest that manipulating the composition of the gut microbiome may one day be a strategy for treating or preventing obesity.
