Comparative effects of viable Lactobacillus rhamnosus GG and its heat‐inactivated paraprobiotic in the prevention of high‐fat high‐fructose diet‐induced non‐alcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver alterations worldwide, being gut microbiota dysbiosis one of the contributing factors to its development. The aim of this research is to compare the potential effects of a viable probiotic (Lactobacillus rhamnosus GG) with those exerted by its heat-inactivated paraprobiotic counterpart in a dietary rodent model of NAFLD. The probiotic administration effectively prevented the hepatic lipid accumulation induced by a high-fat high-fructose diet feeding, as demonstrated by chemical (lower TG content) and histological (lower steatosis grade and lobular inflammation) analyses. This effect was mainly mediated by the downregulation of lipid uptake (FATP2 protein expression) and upregulating liver TG release to bloodstream (MTTP activity) in rats receiving the probiotic. By contrast, the effect of the paraprobiotic preventing diet-induced liver lipid accumulation was milder, and mainly derived from the downregulation of hepatic de novo lipogenesis (SREBP-1c protein expression and FAS activity) and TG assembly (DGAT2 and AQP9 protein expression). The obtained results demonstrate that under these experimental conditions, the effects induced by the administration of viable L. rhamnosus GG preventing liver lipid accumulation in rats fed a diet rich in saturated fat and fructose differ from those induced by its heat-inactivated paraprobiotic counterpart.