Gislane Lelis Vilela de Oliveira

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important therapeutic strategy for hematological malignancies and other diseases but remains associated with substantial morbidity and mortality. Although microbial dominance has been extensively investigated in the gut microbiota, its dynamics and clinical implications in the oral microbiota remain poorly understood. In this prospective multicenter study, longitudinal oral mucosal samples were collected from pre-conditioning to six months post-transplantation in Brazilian patients undergoing allo-HSCT, and microbiota composition was assessed by 16S rRNA gene sequencing. Associations between oral dominance and death within D+180, disease relapse, and acute graft-versus-host disease (aGvHD) were evaluated using competing-risk methods, while predictors of oral dominance were assessed using mixed-effects logistic regression. Among 90 patients, 244 oral samples were analyzed. Alpha diversity significantly decreased during the first 30 days post-allo-HSCT compared with healthy controls. Oral dominance occurred in 87.8% of patients, with Streptococcus, Veillonella, and Rothia being the most frequent dominant genera. Streptococcus dominance was associated with a higher cumulative incidence of moderate-to-severe aGvHD, whereas Rothia dominance was associated with a higher cumulative incidence of disease relapse. These findings demonstrate substantial oral microbiota disruption during allo-HSCT and suggest that specific taxonomic patterns may be associated with clinically relevant transplant outcomes.

Obesity is an adiposity-based low-grade chronic inflammatory disease characterized by excessive fat accumulation and/or dysregulated adipose function, affecting health, quality of life, and mortality. Despite the implementation of public health strategies and individualized therapeutic interventions, obesity currently affects more than one billion people worldwide. Although the distinction between preclinical obesity (PCO) and clinical obesity (CO) has recently been conceptually established, practical tools capable of translating this distinction into clinical diagnosis are still lacking. In this study, we proposed a novel diagnostic framework in which the SF-36 Role-Physical (RP) domain functions as a screening tool to identify physical limitations associated with CO. The framework integrates anthropometric criteria (body mass index and waist circumference), organ dysfunction (presence of comorbidities), and objectively defined physical limitations based on RP domain cutoff values. To validate the framework, patients’ inflammatory profiles were evaluated. Our results demonstrated that stratification based on this functional model could identify a phenotype characterized by a distinct pro-inflammatory profile. CO patients exhibited significantly increased IL-6 and IL-17A levels compared with the PCO and overweight groups. Taken together, these findings suggest that this approach may serve as a simple, low-cost, and clinically applicable strategy to support differentiation between preclinical and clinical obesity. However, larger longitudinal and multicenter studies are needed to validate these findings.

The role of zonulin as a biomarker of intestinal permeability in the allogeneic hematopoietic stem cell transplantation (allo-HSCT) setting remains poorly understood. In this study, we aimed to evaluate serum zonulin dynamics, identify its predictors, and assess its prognostic significance in patients undergoing allo-HSCT. This multicenter, prospective cohort study was conducted across four Brazilian hospitals. Eligible participants were patients aged ≥12 years who provided at least one blood sample during the allo-HSCT course. A control group of 15 healthy adult individuals was also included. Serum zonulin levels were quantified using enzyme-linked immunosorbent assay multiple times over the allo-HSCT course. Outcomes included acute graft-versus-host disease, overall survival, and bloodstream infections. A total of 477 blood samples were collected from 140 patients. Compared with the control group, zonulin levels were persistently elevated at all evaluated time points throughout the allo-HSCT course. However, no significant differences were observed among the different time points assessed during transplantation. No clinical or transplantation-related characteristics were identified as significant predictors of elevated zonulin levels. Finally, zonulin did not demonstrate prognostic value for allo-HSCT-related outcomes. Future studies should investigate whether other intestinal permeability biomarkers have prognostic relevance in the allo-HSCT setting.

Obesity is a chronic inflammatory, multifactorial disease characterized by excessive fat accumulation driven by an imbalance between energy intake and energy expenditure. Despite the implementation of public health strategies and individual therapeutic interventions, overweight and obesity affect more than two billion people worldwide. While the distinction between preclinical (PCO) and clinical obesity (CO) has been conceptually established, tools capable of translating this distinction into clinical diagnostics remain lacking. Current approaches typically use quality-of-life questionnaires as outcome measures rather than diagnostic criteria. In this study, we proposed a novel diagnostic framework in which the SF-36 Role-Physical (RP) domain functions as a screening tool to identify CO. We integrated anthropometric criteria (BMI, waist circumference), organ dysfunction (comorbidities), and objectively defined physical limitations (RP domain cutoffs). Results demonstrated that stratifying patients based on this functional model successfully isolated a phenotype characterized by a distinct pro-inflammatory profile. Individuals classified as having CO exhibited significantly increased IL-6 and IL-17A levels compared to PCO and overweight groups, providing biological validation that the SF-36 RP domain can effectively distinguish pathological adiposity from simple weight gain.

In patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), emerging evidence suggests that the oral microbiota may serve as a predictive biomarker. We conducted a systematic review to provide a critical overview of oral microbiota research in the allo-HSCT setting. We searched PubMed, Embase, and Web of Science from inception to December 2025 to identify studies assessing the oral microbiota in allo-HSCT settings. We included all articles reporting detailed data on the oral microbiota in this context and conducted a qualitative synthesis. Risk of bias was assessed using the JBI critical appraisal tools. From 8160 initially identified records, 35 studies evaluating the oral microbiota in 1964 allo-HSCT patients were included. Of these, 27 studies (77%) assessed temporal oral microbiota dynamics and reported dysbiosis in the early post-transplantation period, followed by gradual recovery. Additionally, 27 studies (77%) evaluated the prognostic value of the oral microbiota, identifying associations with key clinical outcomes such as oral mucositis, overall survival, and graft-versus-host disease. Finally, substantial methodological heterogeneity was observed across studies, including differences in sampling techniques, sampling timepoints, and analytical strategies. This systematic review highlights the prognostic and therapeutic potential of the oral microbiota in allo-HSCT and underscores the need for standardized methodologies.

Background: Although Enterococcus domination has been extensively evaluated in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT), the prevalence and clinical implications of other dominant genera remain poorly understood. Objective: In this study, we sought to determine the dynamics, predictors and clinical implications of intestinal domination in Brazilian patients undergoing allo-HSCT. Methods: In a prospective study of four Brazilian centers, fecal specimens were collected longitudinally prior to allo-HSCT until six months post-transplantation. To identify intestinal domination, we performed 16S rRNA gene sequencing using the Illumina platform. We then evaluated the impact of intestinal domination on overall survival and acute Graft-versus-Host-Disease (aGvHD) incidence. Finally, to identify predictors of intestinal domination, we performed a logistic regression model. Results: A total of 192 fecal specimens were collected from 69 patients. No significant changes in alpha or beta diversity were observed over the course of allo-HSCT. Among the 192 specimens, 131 (68%) presented intestinal domination. The top four dominant genera were Bacteroides, Akkermansia, Phascolarctobacterium, and Escherichia-Shigella. No significant associations were found between domination by these genera and either overall survival or aGvHD incidence. Furthermore, no patient-level characteristics, including age, sex, underlying disease, conditioning regimen, or stem cell source, reliably predicted intestinal domination. Conclusions: Our findings reveal a unique intestinal domination fingerprint in Brazilian patients and highlight the importance of geographic context in interpreting microbiota–outcome associations in allo-HSCT settings.

Intestinal dysbiosis represents a critical determinant of clinical outcomes in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Distinct microbiota patterns represent potential prognostic biomarkers and therapeutic targets. However, the exponential growth in microbiota research and analytical complexity has created significant interpretive challenges for clinicians. This review provides a synthesis of current literature examining microbiota fingerprints and their clinical implications. We analyzed key studies evaluating the clinical implications of intestinal microbiota fingerprints in allo-HSCT. Additionally, we examined current therapeutic strategies for microbiota modulation and approaches for translating research findings into clinical practice. We identified three major microbiota fingerprints: (1) decreased intestinal microbiota diversity, (2) reduced abundance of short-chain fatty acid-producing bacteria, and (3) Enterococcus domination. These fingerprints are associated with critical clinical outcomes including overall survival, Graft-versus-host disease, transplant-related mortality, and infection-related complications. While fecal microbiota transplantation and dietary interventions appear promising, current studies suffer from limited sample sizes and lack standardized protocols. Despite significant advances in microbiota research, biological, methodological, and logistical challenges continue to hinder its clinical translation. Understanding microbiota fingerprints represents a promising avenue for improving allo-HSCT outcomes. However, successful clinical implementation requires standardized methodologies, mechanistic studies, and multi-center collaborations to translate research into actionable clinical tools.

Obesity is a multifactorial condition associated with inflammatory processes, intestinal dysbiosis, and impaired quality of life. This study aimed to evaluate food consumption and quality of life in individuals with overweight and obesity, correlating them with inflammatory markers and intestinal permeability. We analyzed 83 patients, divided into three groups: control, overweight, and clinical obesity (CO), according to the new diagnostic criteria. Quality of life was measured using the SF-36 questionnaire, food consumption was assessed using 24-hour dietary recalls, and inflammatory and permeability markers were measured by ELISA and flow cytometry. Individuals with CO had poorer quality of life scores, higher intake of lipids, cholesterol, and saturated fatty acids, and lower consumption of fiber, MUFA, and PUFA. These dietary patterns correlated with higher concentrations of zonulin and inflammatory cytokines (p < 0.05), such as IL-6 and IL-17A, and lower levels of IL-10, IL-4, and IL-2. The findings reinforce the importance of updated diagnostic criteria and highlight the interaction between diet, inflammation, and quality of life in individuals with excess weight.

Background: Although Enterococcus domination has been extensively evaluated in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT), the prevalence and clinical implications of other dominant genera remain poorly understood. Objective: In this study, we sought to determine the dynamics, predictors and clinical implications of intestinal domination in Brazilian patients undergoing allo-HSCT. Methods: In a prospective study of four Brazilian centers, fecal specimens were collected longitudinally from prior to allo-HSCT to six months after. To identify intestinal domination, we performed 16S rRNA gene sequencing using Illumina platform. We then evaluated the impact of intestinal domination on overall survival and acute graft versus host disease (aGvHD) incidence. Finally, to identify predictors of intestinal domination, we performed a logistic regression model. Results: A total of 192 fecal specimens were collected from 69 patients. Among these specimens, 131 (68%) had intestinal domination. The top four dominant genera were Bacteroides, Akkermansia, Phascolarctobacterium, and Escherichia-Shigella. No significant association was identified between intestinal domination by these genera and overall survival and aGvHD incidence. Additionally, we identified that no patient-level characteristic reliably predicts intestinal domination. Conclusion: Our findings suggest that the prognostic significance of intestinal domination may vary according to the dominant genera and to the population being evaluated.