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Abstract In recent years, the development of immunosuppression has become common, and probiotics are a vital immunomodulatory strategy. This study evaluated the alleviating effect of Lactiplantibacillus plantarum (L. plantarum) YY‐112 on cyclophosphamide‐induced immune imbalance and resolved the possible mechanism of action. L. plantarum YY‐112 at 109 CFU/mL lowered loss of body weight and alleviated splenic injury, intestinal injury, and inflammation, according to the hematoxylin and eosin staining. Biochemical results showed that 109 CFU/mL L. plantarum YY‐112 increased interleukin‐10 and immunoglobulin M levels and decreased interferon‐γ levels. Additionally, the immunoregulatory effect at the molecular levels of L. plantarum YY‐112 was analyzed by transcriptome sequencing. L. plantarum YY‐112 significantly upregulated Cr2 and downregulated C5aR1 to regulate the complement system; downregulated S100a8, S100a9, and Mmp9 to inhibit neutrophil aggregation; upregulated Cd19, Cd72, Cd3e, Cd28, Cd80, Cd8a, and histocompatibility‐2‐related genes to regulate B‐ and T‐cell activation; and upregulated Xiap, Malt1, Ikbkb, Mapk11, Mef2c, Mapk12, Ras, and Myc to activate immune signaling pathways. Furthermore, L. plantarum YY‐112 improved intestinal microbial structure and reduced enrichment of Lachnospiraceae_NK4A136_group, norank_f_Lachnospiraceae, Desulfovibrio, Colidextribacter, and Helicobacter. In conclusion, these findings offer valuable insights into the potential mechanisms through which L. plantarum YY‐112 regulates immune imbalance.

Dendrobium officinale (DO) has no side effects and has been used for centuries to treat gastrointestinal diseases in China. Polysaccharides are the primary components of DO (referred to as DOP). In this study, leaf polysaccharides (DOPY) and stem polysaccharides (DOPJ) were extracted to investigate the protective effect on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in mice and explore its mechanisms of action through analyzing the intestinal microbiota and metabolites in cecum contents. The results showed that DOP reduced the disease activity index (DAI), improved colonic pathology, and protected the integrity of the intestinal barrier (Occludin and Muc2) in UC mice. 16S rRNA sequencing suggested that DOP increased the abundance of beneficial bacteria (Turicibacter and Romboutsia) and reduced the abundance of harmful bacteria (Escherichia-Shigella and Parvibacter). Metabolomic analysis revealed that DOP regulated purine metabolism in the intestine, thereby maintaining intestinal mucosal immune homeostasis. These findings suggested that DOP exerted promising protection against DSS-induced ulcerative mice through remolding gut microbiota to regulate purine metabolism.

Melanin naturally exists in organisms and is synthetized by tyrosinase (TYR); however, its over-production may lead to aberrant pigmentation and skin conditions. Loquat (Eriobotrya japonica (Thunb.) Lindl.) flowers contain a variety of bioactive compounds, while studies on their suppressive capabilities against melanin synthesis are limited. Loquat flower isolate product (LFP) was obtained by ethanol extraction and resin purification, and its inhibitory efficiency against TYR activity was investigated by enzyme kinetics and multiple spectroscopy analyses. In addition, the impact of LFP on melanin synthesis-related proteins’ expression in mouse melanoma B16 cells was analyzed using Western blotting. HPLC-MS/MS analysis indicated that LFP was composed of 137 compounds, of which 12 compounds, including flavonoids (quercetin, isorhamnoin, p-coumaric acid, etc.) and cinnamic acid and its derivatives, as well as benzene and its derivatives, might have TYR inhibitory activities. LFP inhibited TYR activity in a concentration-dependent manner with its IC50 value being 2.8 mg/mL. The inhibition was an anti-competitive one through altering the enzyme’s conformation rather than chelating copper ions at the active center. LFP reduced the expression of TYR, tyrosinase-related protein (TRP) 1, and TRP2 in melanoma B16 cells, hence inhibiting the synthesis of melanin. The research suggested that LFP had the potential to reduce the risks of hyperpigmentation caused by tyrosinase and provided a foundation for the utilization of loquat flower as a natural resource in the development of beauty and aging-related functional products.

This study aimed to explore the immunomodulatory activity of Dendrobium officinale leaf polysaccharide (DOLP) in both immunosuppressed and normal mice. The data showed that DOLP significantly reversed thymic and splenic damage in immunosuppressed mice, regulated their peripheral blood cells (PLT, etc.), immune-related cytokines (TNF-α, INF-γ and IL-6) and immunoglobulins (IgA, IgG and IgM) production, and increased the relative abundance of beneficial bacteria (Lactobacillus and Bifidobacterium, etc.) while decreased that of pathogenic bacteria (Desulfovibrio, etc.). In normal mice, DOLP significantly increased immune-related cytokines (TNF-α, INF-γ, and IL-6), gut microbiota diversity, and the relative abundance of beneficial bacteria (unclassified_f_Lachnospiraceae_NK4A136_group, etc.). The results indicated that DOLP could exert immune modulating effects both on immunosuppressed mice and normal mice by modulating immune parameters and gut microbiota. These findings provide new insights into the immune-modulating effects of DOLP and a solid basis for the thorough utilization of DOLP.

The effect of active substances on the gut microbiota is not immediate, especially for some chronic diseases. This study used an in vitro continuous fermentation system to monitor the changes of gut microbiota in three different colon regions under long-term/short-term DOLP treatment. The results showed that the microbial diversity reached peak on 5th day and remained stable thereafter. Beta diversity analysis showed that the gut microbiota structures of the three regions gradually approached during fermentation. The contents of propionic acid, butyric acid, and valeric acid first increased and then decreased, while isobutyric acid and isovaleric acid first decreased and then increased. Alistipes and Oscillibacter were the key genera in regulating the gut microbiota structure. In summary, Long-term consumption of DOLP has varying effects on the gut microbiota over time, and for the purpose of adjusting the gut microbiota, the most effective duration appears to be continuous consumption for 5 days.

A potentially novel probiotic strain, YY-112, was previously isolated and identified as Lactiplantibacillus pentosus using 16S rDNA sequencing. The whole genome analysis showed that strain YY-112 has the potential to metabolize carbohydrates in the gastrointestinal environment and to regulate immunity. Further, comparative genomics analysis revealed that strain YY-112 was Lactiplantibacillus plantarum (L. plantarum) with more unique genes. The results of in vivo tests showed that L. plantarum YY-112 had no adverse effects and restored the damaged spleen and intestinal barrier of immunocompromised mice. L. plantarum YY-112 recovered the normal levels of lymphocytes, serum cytokines (Interferon-γ, tumor necrosis factor α, and interleukin-6), immunoglobulins (Ig) (IgA, IgM, and IgG) and lipids (albumin, cholesterol, triglyceride). Additionally, L. plantarum YY-112 might indirectly enhance the immune system by improving the intestinal microbiota structure. These results supported the potential of L. plantarum YY-112 as a probiotic to regulate the immune system of hosts.

To investigate the behavior of all-trans-β-carotene during digestion, in-vitro digestion coupled with HPLC-DAD, Raman spectroscopy and Fourier transform-infrared spectroscopy were used to monitor it. All-trans-β-carotene reduced by 75% during the in-vitro digestion and had a highest degradation during intestinal digestion compared with oral and gastro digestion. All-trans-β-carotene occurred isomerization and degradation during oral digestion and occurred degradation during gastro and intestinal digestion. Isomers were identified as 15-cis-β-carotene and 9-cis-β-carotene, degradation products were compounds with function group of C–O, C–O–C or C=C–C=C. The biological fate of β-carotene during digestion was clarified, and one of the reasons for low bioavailability of β-carotene was explained by high degradation rate during digestion.

Dendrobium officinale is widely used as a health supplement, but its specific impact on healthy gut microbiota has not yet been clarified, nor has its impact on different human genders. To overcome the problems mentioned above. DOP was extracted and purified with an 8000–12,000 Da dialysis bag. The molecular weight and monosaccharide composition were determined using HPGPC and GC. Gas chromatography was used to detect the content of SCFA. 16S rDNA sequencing was used to analyze the diversity of human microbiota. The results showed that DOP contained two fractions, with an average molecular weight of 277 kDa and 1318 Da, and mainly composed of mannose and glucose. DOP can increase the relative abundance of benign microbiota and decrease the harmful types. Propionic acid content in women was significantly increased after DOP treatment. Finally, the correlation analysis revealed that DOP was beneficial to the microbiota of both men and women. It can be concluded from the results that DOP is a health supplement suitable for humans, and especially women.

Proanthocyanidins (PACs) have been proven to possess a wide range of biological activities, but complex structures limit their study of structure–function relationships. Therefore, an efficient and general method using hydrophilic interaction high-performance liquid chromatography coupled with high-resolution quadrupole time-of-flight tandem mass spectrometry (HILIC-QTOF-MS) was established to analyze PACs from different plant materials. This method was successfully applied to characterize PACs from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves (BLPs), sorghum testa (STPs) and grape seeds (GSPs). BLPs with the degree of polymerization (DP) from 1 to 8 were separated. BLPs are mainly B-type prodelphinidins and A-type BLPs were first found in this study. STPs and GSPs belonging to procyanidins showed DP from 3 to 11 and 2 to 12, respectively. A-type linkages were found for every DP of STPs and GSPs, which were first found. These results showed that HILIC-QTOF-MS can be successfully applied for analyzing PACs from different plant materials, which is necessary for the prediction of their potential health benefits.

In the present study, the neuroprotective effects of Chinese bayberry leaves proanthocyanidin (BLPs) were investigated by targeting at Aβ fibrillization and neurotoxicity. Two types of BLPs, the Sephadex-LH20 purified BLPs (SPBLPs) and the ultrasound degraded BLPs (UDBLPs) were investigated to identify the potential function to inhibit Aβ fibrillization and neurotoxicity. The result revealed that both BLPs could interfere with self-aggregated Aβ and form a complex, therefore, inhibit Aβ fibrillogenesis, Aβ secondary structure transformation, Aβ-induced cytotoxicity and block the consequent apoptosis through Bcl-2/Bax and caspase signaling pathway. The neuroprotective effect reached its maximum at a dose of 20 μg/mL for both BLPs in the Aβ-induced cytotoxicity model, although the effect of UDBLPs is much stronger than SPBLPs. This is the first reports on the inhibitory effects of BLPs with different mDP on Aβ induced toxicity, and ultrasonic treatments of BLPs can improve its neuroprotection effect.

Chinese bayberry leaves proanthocyanidin (BLPs) contain epigallocatechin-3-O- gallate (EGCG) as its terminal unit and most of its extension units, which is unusual in the plant kingdom. The present study compared the antioxidant and anti-proliferative activities of BLPs prepared from different purification stages. Low-molecular-weight BLPs were prepared by ultrasonic treatment. Results revealed that the antioxidant activities of BLPs were strongly related to the content of total phenolics and proanthocyanidins; however, the cellular assay indicated that the mean degree of polymerization (mDP) played a vital role in the cellular antioxidant activity (CAA) of BLPs. The ultrasonic depolymerized BLPs with lower mDP (3.6 ± 0.3) exhibited a much higher CAA (EC50 = 0.042 ± 0.005 mg/mL) than other groups, which suggests that bioavailability is crucial to the cellular antioxidant potential of BLPs. Additionally, BLPs strongly inhibited HepG2 proliferation in a dose-dependent manner. Our results indicated that BLPs could be a valuable resource of bioactive compounds to promote consumer health.

Chinese bayberry leaf proanthocyanidins (BLPs) are Epigallocatechin gallate (EGCG) oligomers or polymers, which have a lot of health-promoting activity. The activity is closely related to their behavior during in vitro digestion, which remains unknown and hinders further investigations. To clarify the changes of BLPs during gastrointestinal digestion, further research is required. For in vitro digestion, including gastric-intestinal digestion, colon fermentation was applied. Caco-2 monolayer transportation was also applied to investigate the behavior of different BLPs with different degrees of polymerization. The trimers and the tetramers were significantly decreased during in vitro gastric-intestinal digestion resulting in a significant increase in the content of dimers. The dimers and trimers were the main compounds utilized by gut microbiota and they were assumed not to degrade through cleavage of the inflavan bond. The monomers and dimers were able to transport through the Caco-2 monolayer at a rate of 10.45% and 6.4%, respectively.

The effects of eating fresh citrus fruits including two varieties of mandarins, one of sweet oranges, one of grapefruit, two of pomelo, and one of kumquat cultivated in China on endogenous antioxidant enzymes were investigated by in vitro digestion and HepG2 cells. The correlations between enzyme activity and cell uptake of phytochemicals and cellular antioxidant capacities were analyzed. The results showed that most fresh citrus fruits increased the endogenous antioxidant activity. Bairoumiyou, Hongroumiyou, Ponkan, and Jinju after digestion significantly increased the activity of catalase (P <0.05). Hongroumiyou, Bairoumiyou, Ponkan navel orange, and Jinju after digestion significantly increased glutathione peroxidases (GPxs) activity (P <0.05), while Huyou and satsuma could not increase the activity of GPxs after digestion. Thioredoxin oxidoreductase activity was improved significantly by most of the digested whole citrus fruits except Ponkan (P <0.05) and thioredoxin oxidoreductase added whole citrus fruits had a higher increase than added citrus fruits extracts. The results indicated that edible whole citrus fruits had similar effects as extracts on enzymes. [ABSTRACT FROM AUTHOR]