A research group from the Institute of Agrochemistry and Food Technology (IATA-CSIC), located in the scientific-academic area of the University of Valencia Science Park, publishes a review paper in the journal Nature Microbiology, in which they have examined how inulin, a fiber present in some foods, contributes to alleviate non-alcoholic steatohepatitis in mice.
The Microbial Ecology, Nutrition and Health group at the Institute of Agrochemistry and Food Technology (IATA-CSIC), located at the University of Valencia Science Park (PCUV), has just published the review of a study in Nature Microbiology that evaluates how the interaction between the intestinal microbiota of mice and inulin, a soluble dietary fiber naturally present in foods such as artichoke, asparagus, onion or leek, generates a compound that helps alleviate non-alcoholic steatohepatitis (NASH), a soluble dietary fiber naturally present in foods such as artichoke, asparagus, onion or leek, generates a compound that helps to alleviate non-alcoholic steatohepatitis (NASH), a disease that can lead to liver cirrhosis.
Dietary fibers are complex carbohydrates that serve as nutrients for our intestinal microbiota and sustain the symbiotic relationship that exists with the human organism. These fibers cannot be completely degraded by the digestive enzymes present in the intestine, and it is the bacteria that live there that ferment the fibers. This interaction produces metabolites that help regulate intestinal transit and reduce the risk of metabolic diseases such as diabetes or obesity.
Dietary fibers are complex carbohydrates that serve as nutrients for our intestinal microbiota and sustain the symbiotic relationship that exists with the human organism. These fibers cannot be completely degraded by the digestive enzymes present in the intestine, and it is the bacteria that live there that ferment the fibers
Yolanda Sanz, Alejandra Flor and Marta Olivares, researchers at IATA-CSIC, have conducted an exhaustive review of literature data where they have analyzed how inulin, a soluble fiber that is fermented by our intestinal microbiota, could help prevent the progression of non-alcoholic steatohepatitis (NASH) in mice. NASH is a liver disease characterized by inflammation and fat accumulation (hepatic steatosis), often associated with obesity and type 2 diabetes. In more advanced stages, this disease can lead to liver cirrhosis.
The IATA-CSIC authors have evaluated evidence from a study comparing the effect of a soluble fiber, inulin, and an insoluble fiber, cellulose, in mice with non-alcoholic steatohepatitis. The results show that inulin is more effective than cellulose in attenuating fat accumulation and fibrosis, as well as in dampening inflammation and oxidative stress, characteristic symptoms of NASH.
The IATA-CSIC authors have evaluated evidence from a study comparing the effect of a soluble fiber, inulin, and an insoluble fiber, cellulose, in mice with non-alcoholic steatohepatitis. The results show that inulin is more effective than cellulose in attenuating fat accumulation and fibrosis, as well as in dampening inflammation and oxidative stress, characteristic symptoms of NASH
Bacteria, small metabolite factories
Metabolites produced from bacteria during the fermentation process have a wide range of effects and uses in nature. The studies reviewed by the authors add to the growing evidence supporting the role of metabolites produced by intestinal bacteria in ameliorating diet-related diseases.
In this case, fermentation of inulin by the action of the intestinal bacterium Parabacteroides distasonis led to the production of pentadeconoic acid, which helped reduce hepatic steatosis and inflammation. This finding complements recent studies evidencing that this bacterium could contribute to the reduction of weight gain, hyperglycemia and fat accumulation in mice with obesity.
"Treatments with inulin, P. distasonis or pentadeconoic acid, the resultant of the interaction between dietary fiber and bacteria, protect mice against NASH. These treatments could restore the function of the intestinal barrier," say the authors.
"Treatments with inulin, P. distasonis or pentadeconoic acid, the resultant of the interaction between dietary fiber and bacteria, protect mice against NASH. These treatments could restore the function of the intestinal barrier," say the authors of the study
"In humans, however, these effects depend on more variables than those studied in mice, such as the ability of each individual's microbiota to metabolize specific fibers or each person's lifestyle," they argue. "Nevertheless, this study exemplifies the value of tracking nutrient flows between the microbiota and the human host organism to design diets that modulate the gut microbiota, enhancing desired microbial functions and thus helping to mitigate metabolic diseases with increasing prevalence," they highlight.
Inulin is a non-digestible carbohydrate that is present in many vegetables, fruits and cereals, and is widely used as an ingredient in functional foods. It is found naturally in foods such as artichokes, asparagus, onions and leeks.
Reference:
Flor-Duro, A., Olivares, M. & Sanz, Y. Tracking microbiota fibre breakdown to treat NASH. Nat Microbiol (2023). DOI: https://doi.org/10.1038/s41564-023-01440-9