Pneumocystis jirovecii pneumonia (PJP) is an opportunistic pulmonary infection that commonly occurs in immunocompromised children. We report a case of infantile leukemia complicated by PJP and review the relevant literature. A summary and analysis of 10 infantile leukemia patients with PJP infection (9 cases reported in the literature and 1 case from our center) showed that PJP mostly occurred in the early stages of chemotherapy (80%, 8/10). The main clinical manifestations were dyspnea (100%, 10/10) and hypoxemia (50%, 5/10), while pulmonary imaging findings lacked specificity. In most cases (50%, 5/10), diagnosis was established by identifying pathogens in bronchoalveolar lavage fluid under microscopy. In our case, diagnosis was confirmed using targeted next-generation sequencing (tNGS) of bronchoalveolar lavage fluid. Treatment with intravenous sulfamethoxazole complex was administered in 8 patients, all of whom eventually recovered. PJP may occur in the early stages of chemotherapy for infantile leukemia, thus early prevention is necessary. tNGS facilitates early diagnosis of PJP, and sulfamethoxazole complex remains an effective therapeutic option.
Humans ; Infant ; Bronchoalveolar Lavage Fluid/microbiology* ; Immunocompromised Host ; Leukemia/complications* ; Pneumocystis carinii/isolation & purification* ; Pneumonia, Pneumocystis/diagnosis* ; Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use*

The relationship between gut microbiota and depressive disorder has become a research focus in recent years. Within the microbiota-gut-brain axis, the gut microbiota influences the onset and progression of depressive disorder primarily through the tryptophan metabolic pathway. Tryptophan, an essential amino acid in humans, is subject to dual regulation by intestinal microorganisms, which modulate its metabolic balance via inflammatory stimulation and microbial metabolite production. In depression, excessive activation of the kynurenine branch of tryptophan metabolism leads to the accumulation of proinflammatory and neurotoxic metabolites, thereby exacerbating neuroinflammation in the brain. Intervention studies indicate that the antidepressant-like effects of probiotics and traditional Chinese medicine are associated with remodeling of the gut microbiota, restoration of tryptophan metabolic balance, and alleviation of neuroinflammation. Furthermore, targeted inhibition of kynurenine 3-monooxygenase can mitigate neuroinflammation by regulating microglial activity, thus improving depressive-like behaviors. In summary, the metabolite-inflammation axis represents a central node in the interaction regulation between tryptophan metabolism and the microbiota-gut-brain axis. This provides a theoretical foundation for developing novel therapeutic strategies targeting depression through modulation of gut microbiota-mediated tryptophan metabolism.
Tryptophan/metabolism* ; Gastrointestinal Microbiome/physiology* ; Humans ; Depressive Disorder/microbiology* ; Probiotics/therapeutic use* ; Brain/metabolism* ; Kynurenine/metabolism* ; Metabolic Networks and Pathways ; Animals ; Medicine, Chinese Traditional

OBJECTIVES: As early as the Apollo 11 mission, astronauts experienced ocular, skin, and upper airway irritation after lunar dust (LD) was brought into the return cabin, drawing attention to its potential biological toxicity. However, the biological effects of LD exposure through the digestive system remain poorly understood. This study aimed to evaluate the impact of digestive exposure to lunar dust simulant (LDS) on gut microbiota and on the intestine, liver, kidney, lung, and bone in mice. METHODS: Eight-week-old female C57BL/6J mice were used. LDS was used as a substitute for lunar dust, and Shaanxi loess was used as Earth dust (ED). Mice were randomly divided into a phosphate buffered saline (PBS) group, an ED group (500 mg/kg), and a LDS group (500 mg/kg), with assessments at days 7, 14, and 28. Mice were gavaged once every 3 days, with body weight recorded before each gavage. At sacrifice, fecal samples were analyzed by 16S ribosomal RNA (rRNA) sequencing; inflammatory cytokine expression [interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)] in intestinal, liver, and lung tissues was measured by real-time reverse transcription PCR (real-time RT-PCR); hematoxylin and eosin (HE) staining was performed on lung, liver, and intestinal tissues; Periodic acid-Schiff (PAS) staining was used to assess the integrity of the intestinal mucus barrier, and immunohistochemical staining was performed to evaluate the expression of mucin-2 (MUC2). Serum biochemical tests assessed hepatic and renal function. Femoral bone mass was analyzed by micro-computed tomography (micro-CT); osteoblasts and osteoclasts were assessed by osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) staining. Bone marrow immune cell subsets were analyzed by flow cytometry. RESULTS: At day 10, weight gain was slowed in ED and LDS groups. At days 22 and 28, body weight in both ED and LDS groups was significantly lower than controls (both P<0.05). LDS exposure increased microbial species richness and diversity at day 7. Compared with the PBS and ED groups, mice in the LDS group showed increased relative abundance of Deferribacterota, Desulfobacterota, and Campylobacterota, and decreased Firmicutes, with increased Helicobacter typhlonius and reduced Lactobacillus johnsonii and Lactobacillusmurinus. HE and PAS staining of the colon showed that mucosal structural disruption and goblet cell loss were more severe in the LDS group. In addition, immunohistochemistry revealed a significant downregulation of MUC2 expression in this group (P<0.05). No obvious pathological alterations were observed in liver HE staining among the 3 groups, and none of the groups exhibited notable hepatic or renal dysfunction. HE staining of the lungs in the ED and LDS groups showed increased perivascular inflammatory cell infiltration (both P<0.05). CONCLUSIONS LDS exposure via the digestive route induces gut dysbiosis, intestinal barrier disruption, pulmonary inflammation, bone loss, and bone marrow immune imbalance. These findings indicate that LD exposure poses potential health risks during future lunar missions. Targeted restoration of beneficial gut microbiota may represent a promising strategy to mitigate LD-related health hazards.
Animals ; Dust ; Mice ; Mice, Inbred C57BL ; Dysbiosis/etiology* ; Female ; Gastrointestinal Microbiome/drug effects* ; Moon ; Liver/metabolism* ; Digestive System/microbiology* ; Lung/metabolism* ; Kidney

Patients with depression are more likely to have chronic gastrointestinal (GI) symptoms than the general population, but such symptoms are considered only somatic symptoms of depression and lack special attention. There is a chronic lack of appropriate diagnosis and effective treatment for patients with depression accompanied by GI symptoms, and studying the association between depression and GI disorders (GIDs) is extremely important for clinical management. There is growing evidence that depression is closely related to the microbiota present in the GI tract, and the microbiota-gut-brain axis (MGBA) is creating a new perspective on the association between depression and GIDs. Identifying and treating GIDs would provide a key opportunity to prevent episodes of depression and may also improve the outcome of refractory depression. Current studies on depression and the microbially related gut-brain axis (GBA) lack a focus on GI function. In this review, we combine preclinical and clinical evidence to summarize the roles of the microbially regulated GBA in emotions and GI function, and summarize potential therapeutic strategies to provide a reference for the study of the pathomechanism and treatment of depression in combination with GI symptoms.
Humans ; Gastrointestinal Microbiome/physiology* ; Depression/microbiology* ; Gastrointestinal Diseases/physiopathology* ; Brain ; Animals ; Brain-Gut Axis ; Gastrointestinal Tract/microbiology*

Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging, yet there is limited understanding of gut microbiome variation in advanced age. Here, we performed a metagenomics-based enterotype analysis in a geographically homogeneous cohort of 367 enrolled Chinese individuals between the ages of 60 and 94 years, with the goal of characterizing the gut microbiome of elderly individuals and identifying factors linked to enterotype variations. In addition to two adult-like enterotypes dominated by Bacteroides (ET-Bacteroides) and Prevotella (ET-Prevotella), we identified a novel enterotype dominated by Escherichia (ET-Escherichia), whose prevalence increased in advanced age. Our data demonstrated that age explained more of the variance in the gut microbiome than previously identified factors such as type 2 diabetes mellitus (T2DM) or diet. We characterized the distinct taxonomic and functional profiles of ET-Escherichia, and found the strongest cohesion and highest robustness of the microbial co-occurrence network in this enterotype, as well as the lowest species diversity. In addition, we carried out a series of correlation analyses and co-abundance network analyses, which showed that several factors were likely linked to the overabundance of Escherichia members, including advanced age, vegetable intake, and fruit intake. Overall, our data revealed an enterotype variation characterized by Escherichia enrichment in the elderly population. Considering the different age distribution of each enterotype, these findings provide new insights into the changes that occur in the gut microbiome with age and highlight the importance of microbiome-based stratification of elderly individuals.
Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Bacteroides ; China ; Diabetes Mellitus, Type 2/microbiology* ; Escherichia coli/classification* ; Gastrointestinal Microbiome/genetics* ; Metagenomics ; East Asian People

Chemical communication in plant-microbiome and intra-microbiome interactions weaves a complex network, critically shaping ecosystem stability and agricultural productivity. This non-contact interaction is driven by small-molecule signals that orchestrate crosstalk dynamics and beneficial association. Plants leverage these signals to distinguish between pathogens and beneficial microbes, dynamically modulate immune responses, and secrete exudates to recruit a beneficial microbiome, while microbes in turn influence plant nutrient acquisition and stress resilience. Such bidirectional chemical dialogues underpin nutrient cycling, co-evolution, microbiome assembly, and plant resistance. However, knowledge gaps persist regarding validating the key molecules involved in plant-microbe interactions. Interpreting chemical communication requires multi-omics integration to predict key information, genome editing and click chemistry to verify the function of biomolecules, and artificial intelligence (AI) models to improve resolution and accuracy. This review helps advance the understanding of chemical communication and provides theoretical support for agriculture to cope with food insecurity and climate challenges.
Microbiota/physiology* ; Plants/microbiology* ; Artificial Intelligence ; Ecosystem

Objective:To explore the hypothesis of "pathogen storage pool" by analyzing the local microbial community of adenoids. Methods:Under the guidance of a 70° nasal endoscope, sterile swabs were used to collect secretions from the adenoid crypts of the subjects. The samples were sent to the laboratory for DNA extraction and standard bacterial 16S full-length sequencing analysis. Results:At the species level, the top three microbial communities in adenoid crypts were Bacillus subtilis（18.78%）, Fusobacterium pyogenes（11.42%）, and Streptococcus pneumoniae（9.38%）. Conclusion:The local microbial community of adenoids exhibits a high degree of diversity, including microbial communities from the oral cavity and gastrointestinal tract. Our research results support the hypothesis that adenoids act as a " pathogen reservoir".
Humans ; Adenoids/microbiology* ; RNA, Ribosomal, 16S/genetics* ; Microbiota/genetics* ; Streptococcus pneumoniae/isolation & purification* ; Bacillus subtilis/genetics* ; DNA, Bacterial/analysis*

Objective:The objective of this study is to analyze the detection rate, the pathogenic fungus distribution, risk factors and drug sensitivity of fungal infection of external auditory canal in patients diagnosed with chronic otitis media. Methods:The data of a total of 419 patients with chronic suppurative otitis media or middle ear cholesteatoma who were admitted from January 2019 to February 2023 were retrospectively analyzed. Results:A total of 419 patients were included, and 71 patients（16.9%） were positive for fungal culture. The disease mostly occurred in subjects aged 51-60 years old, and patients over 60 years old（47 cases, 66.2%）. From the fungal culture of external auditory canal secretions, 48 cases（11.4%） of Aspergillus and 14 cases（3.3%） of Candida were identified. The prevalence of fungal cultures in patients with chronic suppurative otitis media（20.8%） was significantly higher than that in patients with middle ear cholectestoma（4.9%）. The detection rate of Fungal was significantly increased after topical treatment with antibiotic ear drops（47.0% vs 13.6%）. Most of the isolated fungal strains are wild-type, and they are the sensitivity to voriconazole and fluconazole was the highest（97.2%）. For patients with positive fungal culture, iodoform gauze with triamcinolone acetonide and econazole cream was used to fill the external auditory canal during surgery. There was no significant difference in the tympanic membrane healing rate between patients with positive fungal culture and patients with negative fungal culture at 3 weeks after surgery（98.6% vs 97.7%）. Conclusion:Fungal infections of external auditory canal in patients with chronic otitis media tend to occur in older patients, which is more common in patients with chronic suppurative otitis media. Long-term topical treatment with antibiotic ear drops is an independent risk factor for fungal infection of external auditory canal in patients with chronic otitis media. The isolated fungal strains were highly sensitive to antifungal drugs. Therefore, it is advisable to refrain from employing topical antibiotic treatment for elderly patients with chronic suppurative otitis media/middle ear cholesteatoma, abuse of local antibiotic therapy should be avoided, and Fungal-related pathogenic examinations should be actively performed and anti-fungal drugs should be added if necessary.
Humans ; Middle Aged ; Female ; Male ; Risk Factors ; Retrospective Studies ; Chronic Disease ; Otitis Media, Suppurative/microbiology* ; Ear Canal/microbiology* ; Antifungal Agents/therapeutic use* ; Adult ; Mycoses/epidemiology* ; Aspergillus/isolation & purification* ; Candida/isolation & purification* ; Otitis Media/complications* ; Aged ; Cholesteatoma, Middle Ear/microbiology*

Chronic rhinosinusitis with nasal polyps（CRSwNP） represents a prevalent inflammatory disorder, which is often accompanied by nasal congestion, mucopurulent discharge, olfactory dysfunction, dizziness, and headache. Staphylococcus aureus（SA）, a predominant opportunistic pathogen within the sinonasal microenvironment, has been implicated in modulating the pathogenesis and progression of CRSwNP through multifaceted mechanisms. The physiological activities of SA-dependent quorum-sensing system and biofilm in the nasal microenvironment, including interactions with host, fungi, viruses, and other bacteria, as well as the effects of important superantigens secreted by SA on the microenvironment and immune barrier, are briefly reviewed in this article. These insights provide theoretical foundations for elucidating CRSwNP mechanisms and advancing clinical therapeutic strategies.
Humans ; Sinusitis/microbiology* ; Nasal Polyps/microbiology* ; Staphylococcus aureus ; Chronic Disease ; Rhinitis/microbiology* ; Staphylococcal Infections/microbiology* ; Quorum Sensing ; Biofilms ; Rhinosinusitis

BACKGROUND: Several randomized controlled studies have suggested that the prophylactic use of proton pump inhibitors (PPIs) in intensive care unit (ICU) patients could not reduce the incidence of gastrointestinal bleeding (GIB) and may increase adverse events such as intestinal infection and pneumonia. Gut microbiota may play a critical role in the process. PPIs have been widely prescribed for GIB prophylaxis in patients with acute coronary syndrome (ACS). This study aimed to determine the short-term effects of PPI and histamine-2 receptor antagonist (H2RA) treatment on gut microbiota of ACS patients. METHODS: The study was designed as a single-blind, multicenter, three-parallel-arm, randomized controlled trial conducted at three centers in Beijing, China. We enrolled ACS patients at low-to-medium risk of GIB and randomized (2:2:1) them to either PPI ( n = 40), H2RA ( n = 31), or control group ( n = 21). The primary outcomes were the alterations in gut microbiota after 7 days of acid suppressant therapy. Stool samples were collected at baseline and 7 days and analyzed by 16S ribosomal RNA (rRNA) gene sequencing. RESULTS: There were no significant changes in the diversity of gut microbiota after the short-term use of acid suppressants, but the abundance of Fusobacterium significantly increased and that of Bifidobacterium significantly decreased, especially in PPI users. In addition, the abundance of some pathogenic bacteria, including Enterococcus and Desulfovibrio, was significantly elevated in the PPI users. The fecal microbiota of the PPI users included more arachidonic acid metabolism than that of control group. CONCLUSIONS: PPIs may increase the risk of infection by adversely altering gut microbiota and elevating arachidonic acid metabolism, which may produce multiple proinflammatory mediators. For ACS patients at low-to-medium risk of GIB, sufficient caution should be paid when acid-suppressant drugs are prescribed, especially PPIs. REGISTRATION www.chictr.org.cn (ChiCTR2000029552).
Humans ; Proton Pump Inhibitors/therapeutic use* ; Acute Coronary Syndrome/microbiology* ; Female ; Gastrointestinal Microbiome/drug effects* ; Male ; Middle Aged ; Histamine H2 Antagonists/therapeutic use* ; Aged ; Single-Blind Method