José Félix Aguirre-Garrido

Background/Objectives: Gut dysbiosis in children with autism spectrum disorder (ASD) has been associated with alterations in microbial ecology and metabolic function that may contribute to gastrointestinal dysfunction and the severity of clinical manifestations. Synbiotic and probiotic supplementation has emerged as a promising microbiome-targeted strategy for ASD; however, its effects on gut microbiome composition, functional potential, and clinical outcomes remain incompletely understood. We conducted a longitudinal study of Mexican children diagnosed with ASD to analyze changes in the composition, diversity, and functional potential of the gut microbiome during six months of multi-strain synbiotic supplementation. Methods: Stool samples were collected from 25 children with ASD at baseline and after 3 and 6 months of multi-strain synbiotic supplementation. Gut microbiome composition and diversity were analyzed by 16S rRNA gene sequencing, whereas whole metagenome sequencing (WMS) was performed in a subset of samples to evaluate the functional potential of the fecal microbiome. Gastrointestinal symptoms were assessed using the Rome IV criteria, and ASD severity was evaluated with the Childhood Autism Rating Scale (CARS). Results: Twenty-five children with ASD completed the 6 months of synbiotic supplementation. Overall, ASD severity decreased, reflected by a reduction in total CARS score, and improvements in several CARS domains. Gastrointestinal symptoms also decreased significantly. Longitudinal microbiome profiling revealed significant taxonomic and diversity changes over the supplementation period, while WMS identified changes in microbial metabolic potential, including enrichment of tryptophan biosynthesis pathways and reduced L-rhamnose degradation. Conclusions: This exploratory research provides proof-of-concept evidence supporting multi-strain synbiotic supplementation in children with ASD. Larger controlled studies are needed to confirm these findings and clarify their relevance to microbiota–gut–brain axis interactions. The observed concordance between clinical improvements and microbiome remodeling supports further investigation of microbiome-targeted interventions according to ASD severity and duration of supplementation.

Sexually transmitted infections remain a major public health concern among men who have sex with men (MSM), particularly due to the high frequency of coinfections and the limitations of syndromic management. This study aimed to describe the frequency of bacterial sexually transmitted and urogenital pathogens among symptomatic MSM attending two specialized sexual health clinics in Mexico City. A prospective cross-sectional study was conducted with 150 adult MSM presenting symptoms suggestive of urethritis. Urethral swab samples were analyzed using a multiplex real-time polymerase chain reaction (PCR) assay for the detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum, and Trichomonas vaginalis. At least one pathogen was detected in 91/150 participants (60.7%). N. gonorrhoeae was the most frequent pathogen (33.3%), followed by U. urealyticum (15.3%), M. genitalium (9.3%), and C. trachomatis (9.3%). Coinfections were identified in 15 participants, representing 10.0% of the total population and 16.5% of those with a positive PCR result. Most coinfections involved N. gonorrhoeae, particularly with C. trachomatis. These findings provide descriptive microbiological evidence on the frequency and coinfection patterns of bacterial sexually transmitted infections (STIs) associated pathogens among symptomatic MSM attending specialized sexual health clinics in Mexico City. The high detection rate and occurrence of concurrent infections highlight the limitations of syndromic management and support the value of timely multiplex molecular diagnostics to improve etiological characterization, antimicrobial stewardship, and clinical decision-making in this population.

Crater Lake (Isabel Island, Mexico) is a meromictic, stratified, haloalkaline system. To identify and characterise PHB depolymerases across the vertical physicochemical gradients of the lake, we analysed seven metagenomes from the water column (0–23 m), one sediment metagenome, and the genomes of two organisms (HB105m and VN105m) isolated from 5 m. Taxonomic profiles revealed vertical stratification: Actinobacteriota and Cyanobacteriota dominated surface waters, while Pseudomonadota, Bacillota, and Bacteroidota prevailed in deeper layers and sediments. Alpha‐diversity indices peaked at 5 and 20 m and declined at 23 m. We identified 16 putative PHB depolymerases spanning a broader phylogenetic range than previously documented for haloalkaline ecosystems. These included homologues affiliated with Vreelandella , Thiomicrorhabdus , Chloroflexota, Candidatus Cloacimonadota, and Desulfobacterales. The structural variation observed in lipase‐box motifs and signal peptides suggests functional differentiation linked to redox and oxygen gradients across depths. Phylogenetic analysis of predicted and reference enzymes showed depth‐specific clustering, with extracellular depolymerases predominant in oxic layers and intracellular forms more common in microoxic–anoxic zones. Overall, our results expand the known diversity of PHB‐degrading lineages in extreme environments and highlight several candidate enzymes with potential biotechnological relevance for future experimental characterisation.

Gut microbiota (GM) plays a pivotal role in human health and disease, and its alterations have been implicated in various neurological disorders, including Parkinson's disease (PD). Growing evidence reveals correlations between the abundance of specific bacterial taxa and the severity of motor symptoms and intestinal dysfunction in PD. Moreover, bacterial metabolites have been shown to influence α‐synuclein (α‐syn) aggregation and neurodegeneration. This narrative review aims to explore the current understanding of the gut‐brain axis in PD, specifically the connection between GM and α‐syn function in PD experimental models and patients. Several therapeutic strategies aimed at modulating gut microbiota, such as dietary interventions, fecal microbiota transplantation, and targeted bacterial therapies with the goal of alleviating or preventing PD symptoms, are examined. Understanding the mechanisms through which GM influence neurodegeneration, including inflammation, immune modulation, and microbial metabolite production, offers promising avenues for the development of novel therapeutic strategies targeting the microbiome.

Neisseria gonorrhoeae causes gonorrhea, a sexually transmitted infection that is a global public health problem. Preventive measures are essential to avoid the spread of the bacteria and the development of multi-drug resistant strains. The aim of this review is to describe the main characteristics of N. gonorrhoeae focus on diagnosis, antimicrobial resistance, and treatment. This document can be useful for the medical professional to become knowledgeable as to the current state diagnosis and treatment of gonorrhea

Dysfunction in the prefrontal cortex can lead to cognitive inflexibility due to multifactorial causes as included cardiometabolic disorders, stress, inadequate diets, as well as an imbalance of the gut–brain axis microbiota. However, these risk factors have not been evaluated jointly. The purpose of this study was to evaluate the effect of physical stress (MS: Male Stress and FS: Female Stress) and high-fat diet (MD: Male Diet and FD: Female Diet) supplementation on the gut microbiota and cognitive flexibility. Methods: The study was performed on 47 mice, 30 male (M) and 17 female (F) BALBc, exposed to chronic stress physical (S) and high-fat diet (D). Cognitive flexibility was evaluated using the Attentional Set-Shifting Test (ASST) and the gut microbiota composition in terms of relative abundance (%) and alpha–beta diversity. Results: Results showed that S and D reduced cognitive flexibility in male and female mice (p < 0.0001). Significant changes occurred in Alistipes spp. (MM vs. MS:MD; p < 0.0001), Barnesiella spp. (FC vs. FS; p = 0.0002; FC vs. FD, p = 0.0033); Dorea spp. (MC vs. MD, p = 0.0008; MM vs. MD, p < 0.0001) and Lactobacillus spp. (MC vs. MD and FM vs. FS, p < 0.0001; FM vs. MD, p = 0.0393) genera among groups. Predictive functional analysis (QIIME2 and PICRUSt2) showed a significant increase in the expression of histidine kinase, alanine dehydrogenase, glutamine synthase, glutamate synthase, arginine succinyl synthase, and tryptophan synthase genes (p < 0.05), the latter being a precursor of serotonin (5-HT). Conclusions: Chronic physical stress and a high-fat diet modify cognitive flexibility and the composition and predictive function of the gut microbiota.

Introduction. Staphylococcus aureus is a bacterium that colonizes various human sites. The pharynx has been considered as a site of little clinical relevance and little studied. Recently, it has been reported that S. aureus can colonize more the pharynx than the nose. In addition, S. aureus can persist in these sites for prolonged periods of time. Hypothesis. The composition of the pharyngeal and nasal microbiome will differ between persistent, intermittent carriers and non-carriers of S. aureus. Aim. Determine whether the pharyngeal and nasal microbiome is different between carriers and non-carriers of S. aureus. Methodology. S. aureus carriers were monitored by means of pharyngeal and nasal exudates of apparently healthy adult university students for 3 months. Samples from individuals of the same carrier type were pooled, and DNA was extracted and the 16S rRNA was sequenced. The sequences were analysed in MOTHUR v.1.48.0 software, by analysing the percentages of relative abundance in the STAMP 2.1.3 program, in addition to the predictive analysis of metabolic pathways in PICRUSt2. Results. A greater colonization of S. aureus was found in the pharynx than in the nose. The microbiomes of S. aureus carriers and non-carriers do not show significant differences. The main microbiome difference found was between pharyngeal and nasal microbiomes. No significant differences were found in the abundance of the genus Staphylococcus in pharyngeal and nasal S. aureus carriers and non-carriers. The nasal microbiome was found to have more variation compared to the pharyngeal microbiome, which appears to be more stable between individuals and pools. Predictive analysis of metabolic pathways showed a greater presence of Staphylococcus-associated pathways in the nose than in the pharynx. Conclusion. S. aureus can colonize and persist in the pharynx in equal or greater proportion than in the nose. No statistically significant differences were found in the microbiome of the pharyngeal and nasal carriers and non-carriers of S. aureus, but the pharyngeal and nasal microbiomes are different independent of the type of S. aureus carrier or non-carrier. Therefore, the microbiome apparently does not influence the persistence of S. aureus.

Type 2 diabetes mellitus (T2DM) is a multifactorial disease, influenced by dietary and environmental factors that can modify the intestinal microbiota. The aim of this study was to evaluate changes in the composition and diversity of the intestinal microbiota associated with carbohydrate (CHO) consumption in T2DM patients. Forty patients participated, with and without T2DM. Fecal samples were collected for the characterization of microbial diversity from the massive sequencing of the 16S rRNA gene. Carbohydrate consumption was quantified using the Frequency Consumption Foods questionnaire (FCF), the groups were categorized according to Body Mass Index (BMI) and BMI + CHO consumption. The group without T2DM showed normal biochemical and anthropometric parameters, although they had a high carbohydrate consumption compared to the group with T2DM. At the phylum level, there were differences in relative abundance; the control overweight group (CL–OW > CHO) and T2DM-Normal Weight > CHO patients had increased Bacteroides and decreased Firmicutes. In contrast, the CL–OW > CHO and T2DM-OW < CHO patients, showed reduced Bacteroidetes and an elevated amount of Firmicutes. At the genus level, the differences were in the relative abundance of Roseburia, Clostridium_IV, Prevotella, and Sporobacter, associated with the consumption of carbohydrates. The groups that consumed high amounts of carbohydrates, regardless of whether they had diabetes mellitus or were overweight, had a significantly reduced proportion of Faecalibacterium, an altered proportion of Bacteroides. The high consumption of carbohydrates showed considerable modifications in the composition and diversity of the bacterial communities.

Type 2 diabetes mellitus (T2DM) is a multifactorial disease, influenced by dietary and environmental factors that can modify the intestinal microbiota. The aim was to evaluate changes in composition and diversity of the intestinal microbiota, associated with carbohydrate (CH) consumption in T2DM patients. Forty patients participated, with and without T2DM. Feces samples were collected for the characterization of microbial diversity from the massive sequencing of the 16S rRNA gene. Carbohydrate consumption was quantified from the FCF, the groups were categorized according to BMI and BMI + CH consumption. The group without T2DM showed normal biochemical and anthropometric parameters, although it had high carbohydrate consumption compared to the group with T2DM. At the Phylum level, there were differences in relative abundance, Control overweight group (CL–OW>CH) and T2DM-Normal Weight > CH patients, had increased Bacteroides and decreased Firmicutes. In contrast, CL–OW>CH and T2DM-OW<CH, showed reduced Bacteroidetes and elevated Firmicutes amount. At the genus level, the differences were in the relative abundance of Roseburia, Clostridium_IV, Prevotella, and Sporobacter, associated with the consumption of carbohydrate. The groups that consumed high amounts of carbohydrates, regardless of whether they had diabetes mellitus and overweight, had a significantly reduced proportion of Faecalibacterium, an altered proportion of Bacteroides. The high consumption of carbohydrate showed considerable modifications in the composition and diversity of the bacterial communities.

Plant growth-promoting rhizobacteria (PGPR) are a group of bacteria that associate with the rhizosphere of plants; one of the most abundant bacterial genera in this ecological niche is Pseudomonas, which is constantly expanding due to the emergence of new species such as Pseudomonas atacamensis, whose discovery in 2019 has led to the characterization of several strains from different environments but taxonomically related. The objective of this work was to phenotypically and molecularly characterize P. atacamensis strain EMP42, isolated from the rhizosphere of Echinocactus platyacanthus. The strain EMP42 is able to use different substrates and reduce oxidative stress in plants. It is capable of improving growth parameters such as the number of inflorescences and the height of the aerial body of Arabidopsis thaliana, as well as the germination and seedling survival of the cacti Echinocactus platyacanthus and Astrophytum capricorne. The genetic structure of P. atacamensis EMP42 consists of a closed chromosome of 6.14 Mbp, and 61.1% GC content. It has 5572 genes, including those associated with PGPR activities, such as the trpABCDE, SAP, phoABPRU and acsABC genes, among others, and three ncRNA loci, nine regulatory regions, five complete rRNA operons and three CRISPR-Cas loci, showing phylogenomic similarities with the reference strain P. atacamensis B21-026. Therefore, this study contributes to the understanding of genomic diversity within P. atacamensis and, particularly, highlights the potential application of strain EMP42 as a PGPR.