No abstract

Background and Aim Chronic inflammation is a major contributor to the initiation and progression of cancers. Lactobacillus helveticus NS8, which was originally separated from fermented koumiss, exhibited anti‐inflammatory functions in our prior studies. In this study, NS8 was investigated for its potential to prevent colitis‐associated colorectal cancer (CAC). Methods The protective effects of NS8 against CAC was explored by employing the azoxymethane plus dextran sodium sulfate‐induced carcinogenesis mouse model. The prevalences of T cells expressing specific inflammatory cytokines were measured by flow cytometry at the early stage of CAC. Inflammatory modulation by NS8 was also tested in the Caco2‐Raw264.7 cell co‐culture system. The alternations in the intestinal microbiota following the health–inflammation–cancer sequence were analyzed by 16S rDNA sequencing. Results Oral intake of NS8 lactobacilli clearly reduced tumor number and the degree of hyperplasia. The increased proliferation of enterocytes at the early stage of CAC was significantly suppressed by NS8, while the level of apoptosis was elevated. The anticancer effects of NS8 were associated with its anti‐colitis outcomes before tumor formation. NS8 significantly suppressed the activation of NF‐κB and upregulated the anti‐inflammatory cytokine IL‐10. Further analysis revealed the marked downregulation of IL‐17‐producing T cells by NS8. Furthermore, NS8 modulated intestinal dysbiosis by promoting beneficial commensal microbes while suppressing cancer‐associated microbes. Notably, Bacteroides acidifaciens was the most sensitive commensal bacteria to NS8 intervention. Conclusion These results provide insight into the protective effects of L. helveticus NS8 against colorectal cancer.

Our findings indicate the potential of cell-free fermented products of lactic acid bacteria in topical photoprotection.

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease and is driven by strong type 2 immune responses. NS8 (NS8), a probiotic strain isolated from Mongolian koumiss, has anti-inflammatory activities. Here, we evaluated the therapeutic potential of NS8 on AD-like skin lesions by using SKH-1 hairless mice that underwent three cycles of epicutaneous sensitization (EC) with ovalbumin (OVA). NS8 (5 × 10 CFU/day) was orally administered to mice from 2 weeks before the first sensitization until the end of the study. NS8 attenuated the symptoms and pathological changes in the skin of AD mice. For example, NS8 reduced epidermal and dermal thickening and significantly restrained the infiltration of mast cells, eosinophils, and CD4 T cells into the dermis. By analysing the Th1/Th2 cytokines produced in skin lesions, we found that NS8 significantly suppressed the expression of IL-4, IL-5, and IL-13 ( < 0.05), while it had no discernible effect on the expression of IFN-γ. Systemically, NS-8 reduced the total IgE and OVA-specific IgE levels in serum ( < 0.05). Our study demonstrates that oral administration of . NS8 effectively alleviates AD severity in mice by suppressing the Th2 immune response. NS8 may be a promising candidate for prophylactic and therapeutic treatments of allergic diseases, such as AD.