Commensal fungi Candida albicans modulates dietary high-fat induced alterations in metabolism, immunity, and gut microbiota

Abstract Obesity and its associated diseases represent a growing health concern. Despite a strong correlation between gut microbiota and obesity, a limited study is available to suggest the direct involvement of fungus in host physiology. Candida albicans survives as a commensal fungus in the gastrointestinal tract, and its excessive growth causing infections in immune-suppressed individuals is widely accepted. However, any mutualistic relationship that may exist between C. albicans and the host remains outstanding. Here we show that the dietary C. albicans do not cause any noticeable infections, and our metagenomics analyses suggest that it colonizes in the gut and modulates microbiome dynamics which in turn negates the high-fat diet induced uncontrolled body weight gain, metabolic hormonal imbalances, and inflammatory response. Interestingly, adding C. albicans to a non-obesogenic diet stimulates the appetite regulated hormones and helped the mice gain healthy body weight. In concert, our results suggest a mutualism between C. albicans and the host, therefore, contrary to the notion, C. albicans is not always an adversary rather a bonafide admirable companion of the host. Finally, we discuss its potential translational implication as a probiotic especially in obese people or people dependent on high fat calorie intakes to manage obesity and associated complications.