Research finds link between gut fungi, bacteria and obesity

New research suggests that yeast fungus and certain types of bacteria in the gut may contribute to obesity as well as fuel gut inflammatory disorders, like Crohn’s disease.
The findings have implications for explaining the growing link between gut health and obesity which, along with physical inactivity, greatly affects the risk of developing metabolic problems like type 2 diabetes.
This time, researchers have found that, not only is there more evidence that an imbalance of gut bacteria can have an impact on metabolic health, it is likely that another factor (fungi) plays into this.
The results come from two independent studies, led by the University of Minnesota and a team of scientists at the centre for Medical Mycology, in Cleveland, USA.
The former reported on the association between the gut microbiome and obesity, in presence of a high-fat diet, and explains part of the link between fungi and the microbes. The latter uncovered how fungi and microbes can team up to cause trouble.
The findings, published in the journals mSphere and Digestive and Liver Disease, show an interaction between diet, and changes in the microbiome happening at the same time as shifts in types of fungi in the gut.
The study conducted in Minneapolis tested this hypothesis in mice. Those fed a high-fat diet, as opposed to a standard chow, had less of a type of yeast called Saccharomyces cerevisiae (S. cereviae), and more of the Candida albicans (C. albicans) kind.
S.cereviae, also known as Brewer’s or Baker’s yeast, is a type of yeast used in making wine and is generally associated with good health. C.albincans is, however, an organism involved in many yeast infections.
There was also newly discovered evidence suggesting that relationships between bacteria and fungi change in response to different diets too.
These relationships, or interactions, are what researchers think may drive someone to gain weight. But, the results are still very much at a preliminary stage and further investigation is warranted.
The other researchers in Cleveland added to these findings. They found signs of abundance of C. tropicalis fungus along with Escherichia coli, known to cause bacterial infections, and Serratia marcescens – a bacteria that can be injurious to cells lining the intestines.
According to the researchers, the bacteria may react with the fungus, and E. coli joins in to form a microbial community of its own. Mice harbouring the three organisms develop gut inflammation, which explains part of the symptomatology in Crohn’s disease.
This is because the gut wall is only one cell thick in many places and most of the immune system is just on the other side of that thin wall. When the integrity of the gut wall lessens, gastrointestinal conditions, like irritable bowel syndromen, can arise.
Researchers will now continue their search for information that can further our understanding of the link between the gut microbiomen, obesity and immune disorders, a well as how to maintain a good balance in fungi and bacteria to prevent disease.