Characterization of the Nutritional Composition of a Biotechnologically Produced Oyster Mushroom and its Physiological Effects in Obese Zucker Rats

Abstract

Scope: Sustainable protein sources are needed to meet the increasing protein demands of a continuously growing world population. This study is focused on the biotechnological production of a protein rich oyster mushroom (Pleurotus sajor-caju; PSC) by valorization of an agricultural side stream and the evaluation of the physiological effects of PSC in a rat model of metabolic syndrome. Methods and results: PSC is produced via submerged cultivation in a 150 L bioreactor that utilizes isomaltulose molasses as its sole carbon source, and is further analyzed for its nutritional composition. A feeding trial is performed using Zucker rats which are fed a 5% PSC supplemented diet, for 4 weeks. Biochemical analyses reveal a significant reduction of the liver lipid concentrations and liver inflammation in the PSC fed obese rats in comparison to the obese rats from the control group. Hepatic qPCR analyses, differential transcript profiling, and enzyme activity measurements reveal a number of altered pathways that may be responsible for these anti-steatotic and anti-inflammatory effects of the mushroom. Conclusion: Bioconversion of a low quality agricultural side stream to an improved protein source is performed by submerged cultured PSC, and the obtained mycelium shows strong anti-steatotic and anti-inflammatory effects.

Influence of a Biotechnologically Produced Oyster Mushroom (Pleurotus sajor-caju) on the Gut Microbiota and Microbial Metabolites in Obese Zucker Rats

“…8 We also found that the lowering of hepatic lipids was accompanied by a reduction of hepatic inflammation and systemic inflammatory parameters. 8 However, the reason underlying the pronounced antisteatotic and anti-inflammatory effect of P. sajor-caju supplementation remains to be shown.…”

“…For this investigation, liver, plasma, and colonic digesta samples from a recently described animal study that utilized Zucker rats were used. 8 The animal experiment was approved by the local Animal Care and Use Committee (Regierungsprasidium Giessen; permission no: JLU 648_M). All experimental procedures outlined followed established guidelines for the care and handling of laboratory animals.…”

“…The study employed 48 Zucker male rats (Crl:ZUC-Lepr fa ) [24 heterozygous (fa/+) lean and 24 homozygous (fa/fa) obese] as experimental animals. Details of the housing conditions are mentioned in a recent study by Maheshwari et al 8 The obese rats were randomly assigned to two groups [obese control (OC) and obese 5% P. sajor-caju (OPSC)] of 12 rats each. Similarly, the lean rats were also randomly assigned to two groups [lean control (LC) and lean 5% P. sajor-caju (LPSC)] of 12 rats each.…”

“…13 Dietinduced changes in BA profiles may affect liver lipid metabolism, considering that the metabolic effects of certain BAs largely differ; for example hydrophobic BAs promote cholesterol absorption, while hydrophilic BAs are potent inhibitors of cholesterol absorption in mice. 14,15 Owing to the high quantity of dietary fibers in P. sajor-caju and the strong effect of indigestible fibers on the gut microbial community, 8 we hypothesized in the present study that P. sajor-caju supplementation-reduced hepatic steatosis in obese Zucker rats was accompanied by a modification of their gut microbiota and alterations in the concentrations of gut microbiota-derived signals such as SCFAs and BAs.…”

Ergothioneine, recent developments

“…These include the association of increased mushroom consumption with decreased risks of dementia [ 133 , 134 ], cardiovascular disease, certain cancers (e.g. prostate and breast cancer) [ 135 , 136 ], IBD [ 137 ], metabolic syndrome [ 138 ], PD and other neurological disorders [ 139 ], viral infections [ 140 ] and many other conditions. Some of the studies attributed these perceived health benefits of mushrooms to the ET present [ 129 , [141] , [142] , [143] ].…”