In recent years, the prevalence of non-alcoholic fatty liver disease (NAFLD) has risen annually, yet due to the intricacies of its pathogenesis and therapeutic challenges, there remains no definitive medication for this condition. This review explores the intricate relationship between the intestinal microbiome and the pathogenesis of NAFLD, emphasizing the substantial roles played by Lactobacillus plantarum and Bifidobacterium bifidum. These probiotics manipulate lipid synthesis genes and phosphorylated proteins through pathways such as the AMPK/Nrf2, LPS-TLR4-NF-κB, AMPKα/PGC-1α, SREBP-1/FAS, and SREBP-1/ACC signaling pathways to reduce hepatic lipid accumulation and oxidative stress, key components of NAFLD progression. By modifying the intestinal microbial composition and abundance, they combat the overgrowth of harmful bacteria, alleviating the inflammatory response precipitated by dysbiosis and bolstering the intestinal mucosal barrier. Furthermore, they participate in cellular immune regulation, including CD4⁺ T cells and Treg cells, to suppress systemic inflammation. L. plantarum and B. bifidum also modulate lipid metabolism and immune reactions by adjusting gut metabolites, including propionic and butyric acids, which inhibit liver inflammation and fat deposition. The capacity of probiotics to modulate lipid metabolism, immune responses, and gut microbiota presents an innovative therapeutic strategy. With a global increase in NAFLD prevalence, these insights propose a promising natural method to decelerate disease progression, avert liver damage, and tackle associated metabolic issues, significantly advancing microbiome-focused treatments for NAFLD.

Carotenoids are tetraterpene compounds acting as precursors to vitamin A, with functions that include protecting eyesight, enhancing immunity, promoting cell growth and differentiation, and providing antioxidative benefits. Lycopene, β-carotene, and astaxanthin are particularly critical for health and have diverse applications in food, health products, and medicine. However, natural carotenoids are encased within cell structures, necessitating mechanical methods to disrupt the cell wall for their extraction and purification—a process often influenced by environmental conditions. Thus, improving the efficiency of carotenoid extraction from natural resources is of great interest. This review delves into the research progress made on the extraction processes, structures, and biological functions of carotenoids, focusing on lycopene, β-carotene, and astaxanthin. Traditional extraction methods primarily involve organic solvent-assisted mechanical crushing. With deeper research and technological advancements, more environmentally friendly solvents, advanced machinery, and suitable methods are being employed to enhance the extraction and purification of carotenoids. These improvements have significantly increased extraction efficiency, reduced preparation time, and lowered production costs, laying the groundwork for new carotenoid product developments.

This study explores the functional attributes of Lactiplantibacillus plantarum (L. plantarum) strains isolated from fermented tomato juice, focusing on their physiological, biochemical, and probiotic characteristics. The identified 66 gram-positive strains included 36 L. plantarum ones, which exhibited robust growth in acidic environments (pH 2.0–5.0) and utilization of various carbohydrates. Notably, seven strains outperformed a commercial strain in extreme acidic conditions. Antioxidant activity varied, with strain A24 showing the highest hydroxyl radical scavenging ability, while strains with high surface hydrophobicity had lower DPPH scavenging activity, indicating no direct correlation between these properties. Strains also showed strain-specific differences in carbohydrate utilization and antibiotic resistance, with some resistant to gentamicin and ciprofloxacin. Survival rates under simulated gastrointestinal conditions were strain-specific, with some strains demonstrating high survival rates, indicating their potential as probiotics. Furthermore, 13 strains used as fermentation starters in tomato juice significantly enhanced antioxidant activity and reduced pH and total soluble solids, indicating efficient sugar utilization and lactic acid production. These findings suggest that L. plantarum strains are well-suited for functional food fermentation and probiotic applications, with strain-specific traits offering versatility for use in acidic food products and probiotic formulations.