Fruits are crucial components of a balanced diet and a good source of natural antioxidants, that have proven efficacy in various chronic illnesses. Various kinds of waste generated from fruit industries are considered a global concern. By utilizing this fruit waste, the international goal of “zero waste” can be achieved by sustainable utilization of these waste materials as a rich source of secondary metabolites. Moreover, to overcome this waste burden, research have focused on recovering the bioactive compounds from fruit industries and obtaining a new strategy to combat certain chronic diseases. The separation of high-value substances from fruit waste, including phytochemicals, dietary fibers, and polysaccharides which can then be used as functional ingredients for long-term health benefits. Several novel extraction technologies like ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE) could provide an alternative approach for successful extraction of the valuable bioactives from the fruit waste for their utilization as nutraceuticals, therapeutics, and value-added products. Most of these waste-derived secondary metabolites comprise polyphenols, which have been reported to have anti-inflammatory, insulin resistance-treating, cardiovascular disease-maintaining, probiotics-enhancing, or even anti-microbial and anti-viral capabilities. This review summarizes the current knowledge of fruit waste by-products in pharmacological, biological, and probiotic applications and highlights several methods for identifying efficacious bioactive compounds from fruit wastes.

In this study, the two lactic acid bacterial strains Enterococcus durans and Enterococcus lactis previously isolated from soft chhurpi, a traditionally fermented milk product prepared by the indigenous community of Sikkim Himalayas and healthy human gut were used. In this study, we attempted to investigate the probiotic attributes, safety, and health beneficial role, and hypercholesterolemia of Enterococcus durans and Enterococcus lactis. Both probiotic potential strains showed good hypocholesterolemic activity in vitro along with tolerance to acid pH (2 and 2.5), tolerance to three bile salts, oxbile, cholic acid, and taurocholic acid (0.5 and 1%), presence of BSH enzyme and its activity, and cell surface adherence. On assessing for safety, both LAB strains were sensitive to antibiotics and exhibited no hemolytic activity. The probiotic strains were tested in vivo in the Sprague–Dawley rats which were divided into five experimental groups: Normal Control (ND), probiotic strain Enterococcus durans HS03 (BSH-negative) and high-cholesterol diet (HCD1), probiotic strain Enterococcus lactis YY1 (BSH-positive) and high-cholesterol diet (HCD2), and a combination of both strains and high-cholesterol diet (HCD3) and Negative Control (HCD). The probiotic-treated groups HCD1, HCD2, and HCD3 showed a decrease in serum cholesterol levels up to 22.55, 6.67, and 31.06%; the TG and VLDL concentrations were 25.39, 26.3, and 33.21%; reduction in LDL-cholesterol was 33.66, 28.50, and 35.87%; and increase of HDL was 38.32, 47.9, and 41.92%. Similarly, the effects of total cholesterol and TG in the liver, kidney and liver histopathology, liver and body lipid index, and oxidative stress in rat liver were also studied. The fecal lactobacilli were more in the samples of the probiotic-treated groups and their fecal coliform and E. coli counts decreased relatively as compared to the control groups in 0, 7, 14, and 21 days. This is the first report on the probiotic potential of Enterococcus durans HS03 and Enterococcus lactis YY1 strains that gives a new insight into the cholesterol-lowering and probiotic product development with wide health attributes.

Endemic fermented vegetables play a crucial role in local cuisine and culture, with traditionally fermented raw green vegetables such as gundruk being a popular practice in North Bengal and Sikkim, India. However, there is a gap in the microbial profiling of these vegetables. This study aimed to explore the diversity of dominant bacterial populations in fermented leafy vegetables using both culture-dependent and culture-independent methods. In addition to isolating bacteria using conventional methods, we conducted phenotypic and biochemical characterization, community DNA isolation, and amplicon sequencing. We also introduced a new approach in bioinformatics analysis: reverse ecology, which analyzes complementation and competition among participant microbes. In conventional culture-dependent techniques, LAB genera such as Lactobacillus, Enterococcus, Leuconostoc, and Pediococcus have been identified as predominant consortia, whereas metagenomic analysis revealed that the microbiome of fermented dried leafy vegetables was mainly composed of Firmicutes, Proteobacteria, Actinobacteria, Bacteroides, and Planctomycetes at the phylum level. Within the Lactobacillaceae family, predominant types included Lactobacillus, Lactococcus, Pediococcus, Leuconostoc, Enterococcus, Vagococcus, Weissella, and Carnobacterium. The microbial metabolism revealed key pathways, such as carbon metabolism, glycolysis, gluconeogenesis, and glyoxylate. Aromatic amino acid degradation, fatty acid metabolism, amino sugar metabolism, nucleotide sugar metabolism, and biosynthesis of nucleotide sugar pathways were also active. The competition index among microbes and human metabolic data was low (0.32–0.44), indicating minimal competition for nutrition. Complementation indices between bacteria and humans were high (0.76–0.88), suggesting a beneficial impact of gundruk microbial populations on human health.