Gut microbiota analyses of cutaneous T-cell lymphoma patients undergoing narrowband ultraviolet B therapy reveal alterations associated with disease treatment

Decreased gut short-chain fatty acids in cutaneous T-cell lymphoma: a novel insight

Short-chain fatty acids (SCFAs) are critical metabolites produced by gut microbiota that play a key role in modulating inflammation and regulating systemic immunity, including against cancer. Decreases in SCFAs can foster a permissive tumor immune environment. Recent studies have shown that cutaneous T-cell lymphoma (CTCL) patients exhibit increasing gut dysbiosis and loss of bacteria predicted to produce SCFAs with increasing disease severity. To investigate this functional connection, we collected stool swab samples from 15 individuals- 8 mycosis fungoides (MF) patients and 7 matched healthy controls (HC)- and quantified concentrations of four SCFAs (acetate, propionate, isovalerate, butyrate) via liquid chromatography-mass spectrometry. Our results demonstrated significantly reduced acetate and propionate concentrations in MF patients when compared to HC (both p = 0.027). Total measured SCFA concentrations were on average lower in MF versus HC, but did not achieve statistical significance (p = 0.063). Both propionate and acetate have been previously demonstrated to promote tumor apoptosis, inhibit tumor proliferation, and enhance antitumor immunity. Thus, dysbiosis-associated reductions in SCFAs may be another contributive factor in the immune dysfunction observed in CTCL. Our pilot findings add to the growing body of knowledge implicating the gut microbiota-SCFA axis in CTCL pathogenesis and offer potential new avenues for therapeutic intervention.

Ionizing radiation improves skin bacterial dysbiosis in cutaneous T-cell lymphoma

Introduction

Cutaneous T-cell lymphoma (CTCL) is closely associated with the host microbiome. While recent evidence suggests that shifts in specific bacterial taxa are associated with response to UV-B, a form of non-ionizing radiation, the impact of ionizing radiation (IR) has not been investigated.

Methods

16S rRNA and tuf gene amplicon sequencing were performed on DNA extracted from swabs of lesional/non-lesional skin of 12 CTCL patients before/after TSEBT or local IR and from 25 matched healthy controls (HC). Microbial diversity and taxonomic profiles were analyzed.

Results

Radiation exposure increased CTCL skin α-diversity to levels approximating HC. TSEBT appeared to carry the greatest effect compared to local IR. Both α and β-diversity differed significantly post versus pre-IR for TSEBT, but not for local IR. IR was associated with decreases in known pathogenic bacteria such as Streptococcus and S. aureus and increases in healthy commensal bacteria such as Anaerococcus, Bifidobacterium and commensal staphylococci including S. pettenkoferi. Substantially more taxa shifts were seen with TSEBT versus local IR.

Discussion

IR not only eliminates CTCL lesions via induction of apoptosis, but also facilitates skin barrier restoration and recolonization of bacterial taxa associated with a healthy skin microbiome. Local IR does not have as strong an effect on the skin microbiome as TSEBT. As skin microbiota act as immunomodulators with local and potentially systemic influence, TSEBT may also improve CTCL lesions via global effects on the skin microbiome. Future larger-scale studies are required to fully elucidate the relationship between cutaneous microbes and IR treatment in CTCL.

Involvement of the gut microbiota in cancer cachexia

Cancer cachexia, or the unintentional loss of body weight in patients with cancer, is a multiorgan and multifactorial syndrome with a complex and largely unknown etiology; however, metabolic dysfunction and inflammation remain hallmarks of cancer-associated wasting. Although cachexia manifests with muscle and adipose tissue loss, perturbations to the gastrointestinal tract may serve as the frontline for both impaired nutrient absorption and immune-activating gut dysbiosis. Investigations into the gut microbiota have exploded within the past two decades, demonstrating multiple gut-tissue axes; however, the link between adipose and skeletal muscle wasting and the gut microbiota with cancer is only beginning to be understood. Furthermore, the most used anticancer drugs (e.g. chemotherapy and immune checkpoint inhibitors) negatively impact gut homeostasis, potentially exacerbating wasting and contributing to poor patient outcomes and survival. In this review, we 1) highlight our current understanding of the microbial changes that occur with cachexia, 2) discuss how microbial changes may contribute to adipose and skeletal muscle wasting, and 3) outline study design considerations needed when examining the role of the microbiota in cancer-induced cachexia.

Metal nanoparticle hybrid hydrogels: the state-of-the-art of combining hard and soft materials to promote wound healing

Wounds represent a grave affliction that profoundly impacts human well-being. Establishing barriers, preventing infections, and providing a conducive microenvironment constitute the crux of wound therapy. Hydrogel, a polymer with an intricate three-dimensional lattice, serves as a potent tool in erecting physical barriers and nurturing an environment conducive to wound healing. This enables effective control over exudation, hemostasis, accelerated wound closure, and diminished scar formation. As a result, hydrogels have gained extensive traction in the realm of wound treatment. Metallic nanoparticle carriers, characterized by their multifaceted responses encompassing acoustics, optics, and electronics, have demonstrated efficacy in wound management. Nevertheless, these carriers encounter challenges associated with swift clearance and nonuniform effectiveness. The hybridization of metallic nanoparticle carriers with hydrogels overcomes the shortcomings inherent in metallic nanoparticle-based wound therapy. This amalgamation not only addresses the limitations but also augments the mechanical robustness of hydrogels. It confers upon them attributes such as environmental responsiveness and multifunctionality, thereby synergizing strengths and compensating for weaknesses. This integration culminates in the precise and intelligent management of wounds. This review encapsulates the structural classifications, design strategies, therapeutic applications, and underlying mechanisms of metal nanoparticle hybrid hydrogels in the context of acute and chronic wound treatment. The discourse delves into the generation of novel or enhanced attributes arising from hybridization and how the current paradigm of wound therapy leverages these attributes. Amidst this continually evolving frontier, the potential of metal nanoparticle hybrid hydrogels to revolutionize wound treatment is underscored.