EPA-rich Nannochloropsis oceanica biomass regulates gut microbiota, alleviates inflammation and ameliorates liver fibrosis in rats.

Omega-3 fatty acids are believed to show anti-fibrotic effects by lowering inflammation and regulating the gut microflora. Marine microalgae are an alternative, sustainable source of omega-3 fatty acids to the conventionally used fish oil. Microalgae N. oceanica is a promising source of EPA, one of the essential omega-3 PUFAs. Current study investigates the inhibitory effects of EPA rich N. oceanica biomass against CCl4 induced liver fibrosis in rats. Here, we studied the anti-fibrotic effects in N. oceanica biomass fed groups: T1 - Low dose (4.16 mg/kg EPA), T2 - Medium dose (8.33 mg/kg EPA) and T3 - High dose (16.66 mg/kg EPA), when compared to fish oil fed group (FO - 16.66 mg/kg EPA) as a positive control. The elevated levels of serum liver biomarker enzymes and cholesterol induced by CCl4 showed a significant reduction in T3. Histopathological analysis showed the protective effects of biomass feeding on inflammation and hepatocyte degeneration. In addition, the abundance of the SCFA producing bacteria like Blautia argi, Romboutsia ilealis, Romboutsia timonensis, Stomatobaculum longum and Limosilactobacillus reuteri markedly increased in the PUFA fed groups. The cholesterol metabolising bacteria Eubacterium coprostanoligenes showed a noteworthy increase upon PUFA administration. Overall results indicate that the ameliorative effects observed upon administration of N. oceanica biomass were comparable to FO in a dose dependent manner. Therefore, we can conclude that N. oceanica biomass supplementation is associated with the alleviation of liver fibrosis in rats.