Wanyi Zhou

Background/Objectives: Chronic colitis presents a growing global health burden with rising incidence. This study investigated the ameliorative effect of Dendrobium officinale polysaccharide (DOP) against dextran sulfate sodium (DSS)-induced chronic colitis in mice, specifically examining its dual modulation of gut microbiota and metabolic pathways. Methods: DOP was extracted and purified from Dendrobium officinale stems and leaves. A chronic colitis model was established in male C57BL/6J mice via DSS induction. Eighty-four mice were randomized into seven groups: control, model, low/high-dose leaf-DOP, low/high-dose stem-DOP, and sulfasalazine positive control. We assessed body weight, disease activity index (DAI), colon length, splenic/thymic indices, inflammatory cytokines, and histopathology (Hematoxylin and Eosin/Alcian blue staining), with tight junction protein and tumor necrosis factor-alpha (TNF-α) expression quantified via immunofluorescence. 16S rRNA sequencing and untargeted metabolomics evaluated microbial and metabolic shifts. Results: DOP significantly attenuated colitis severity, restored colon histoarchitecture, elevated goblet cell counts, upregulated zonula occludens-1 (ZO-1) and occludin expression, and suppressed TNF-α. Crucially, DOP remodeled dysbiosis by enriching beneficial taxa (e.g., Candidatus_Saccharimonas, Lachnoclostridium) while reducing pathogens (Mucispirillum). Metabolomics further elucidated DOP-mediated regulation of purine and nicotinate/nicotinamide metabolism—pathways mechanistically linked to its anti-inflammatory and barrier-repair effects. Conclusions: DOP effectively alleviates symptoms of DSS-induced chronic colitis in mice, protects intestinal barrier integrity, and achieves therapeutic potential through simultaneous regulation of the gut microbiome and metabolome.

Ultraviolet B (UVB) is a major external factor causing ultraviolet damage. This study assessed the protective effects of Dendrobium officinale polysaccharides (DOP) from both stems and leaves on UVB-induced skin damage in HaCaT Human Keratinocytes. Notably, stem DOPs (DOP1J, DOP3J, and DOP8J) outperformed leaf DOPs (DOP1Y, DOP3Y, and DOP8Y) in mitigating UVB-induced damage, with DOP1J and DOP8J demonstrating the highest efficacy in preserving cell proliferation. The DOPs exhibited antioxidant properties by enhancing superoxide dismutase, catalase, and glutathione peroxidase activities, and reducing reactive oxygen species levels. They curtailed cellular aging by inhibiting UVB-induced protein phosphorylation of p38, JNK, and ERK1/2 within the mitogen-activated protein kinase (MAPK) signaling pathway and by suppressing the protein expression of p53 and matrix metalloproteinases (MMPs, including MMP-1 and MMP-9). The mechanism underlying DOPs’ protective effects appears to be a dual-action approach: bolstering antioxidant defenses and dampening the MAPK pathway’s activation, thereby hindering the expression of MMPs. Graphical abstract

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.

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.