Gut fungal imbalances, particularly increased Candida spp., are linked to obesity. This study explored the potential of Lactiplantibacillus plantarum cell-free extracts (postbiotics) to modulate the growth of Candida albicans and Candida kefyr, key members of the gut mycobiota. A minimal synthetic gut model was employed to evaluate the effects of Lactiplantibacillus plantarum postbiotics on fungal growth in mono- and mixed cultures. Microreactors were employed for culturing, fungal growth was quantified using CFU counting, and regression analysis was used to evaluate the effects of postbiotics on fungal growth. Postbiotics at a concentration of 12.5% significantly reduced the growth of both Candida species. At 24 h, both C. albicans and C. kefyr in monocultures exhibited a decrease in growth of 0.11 log CFU/mL. In contrast, mixed cultures showed a more pronounced antifungal effect, with C. albicans and C. kefyr reductions of 0.62 log CFU/mL and 0.64 log CFU/mL, respectively. Regression analysis using the Gompertz model supported the antifungal activity of postbiotics and revealed species-specific differences in growth parameters. These findings suggest that L. plantarum postbiotics have the potential to modulate the gut mycobiota by reducing Candida growth, potentially offering a therapeutic approach for combating fungal overgrowth associated with obesity.

Background: There is great interest in the search for new alternatives to antimicrobial drugs, and the use of synbiotics is a promising approach to this problem. This study evaluated the growth inhibition and antibiofilm activity of the short-chain fatty acids produced by Lacticaseibacillus rhamnosus and Pediococcus acidilactici in combination with inulin-type fructans against Candida albicans. Methods: The growth inhibition of Candida was evaluated using microdilution analysis in 96-well microtiter plates; different concentrations of cell-free supernatants of Lacticaseibacillus rhamnosus and Pediococcus acidilactici were exposed to Candida albicans. The antibiofilm assessment was carried out using the crystal violet staining assay. The short-chain fatty acids were analyzed by gas chromatography. Results: The clinically isolated Candida albicans interacted with supernatants from Lacticaseibacillus rhamnosus and Pediococcus acidilactici and showed significant growth inhibition and antibiofilm formation versus the controls. Lactate and acetic acid were elevated in the supernatants. The results suggest that the supernatants obtained from the synbiotic combinations of Lacticaseibacillus rhamnosus and Pediococcus acidilactici with inulin-type fructans can inhibit the growth and biofilm formation against a clinically isolated Candida albicans strain. Conclusions: These results suggest that synbiotic formulations could be a promising alternative to antifungal drugs in candidiasis therapy.

The structure of mixed microbial cultures—such as the human gut microbiota—is influenced by a complex interplay of interactions among its community members. The objective of this study was to propose a strategy to characterize microbial interactions between particular members of the community occurring in a simulator of the human gastrointestinal tract used as the experimental system. Four runs were carried out separately in the simulator: two of them were fed with a normal diet (control system), and two more had the same diet supplemented with agave fructans (fructan-supplemented system). The growth kinetics of Lactobacillus spp., Bifidobacterium spp., Salmonella spp., and Clostridium spp. were assessed in the different colon sections of the simulator for a nine-day period. The time series of microbial concentrations were used to estimate specific growth rates and pair-wise interaction coefficients as considered by the generalized Lotka-Volterra (gLV) model. A differential neural network (DNN) composed of a time-adaptive set of differential equations was applied for the nonparametric identification of the mixed microbial culture, and an optimization technique was used to determine the interaction parameters, considering the DNN identification results and the structure of the gLV model. The assessment of the fructan-supplemented system showed that microbial interactions changed significantly after prebiotics administration, demonstrating their modulating effect on microbial interactions. The strategy proposed here was applied satisfactorily to gain quantitative and qualitative knowledge of a broad spectrum of microbial interactions in the gut community, as described by the gLV model. In the future, it may be utilized to study microbial interactions within mixed cultures using other experimental approaches and other mathematical models (e.g., metabolic models), which will yield crucial information for optimizing mixed microbial cultures to perform certain processes—such as environmental bioremediation or modulation of gut microbiota—and to predict their dynamics.

The intestinal microbiota plays a key role in the pathogenesis of inflammatory bowel disease (IBD), with its composition varying based on geographic location and dietary factors. This study was performed to examine and compare the bacterial composition of the gut microbiota in Mexican and Spanish individuals with IBD and healthy controls, while also considering the nutritional aspects. This study involved 79 individuals with IBD and healthy controls from Mexico and Spain. The fecal microbiota composition was analyzed using 16S rRNA gene sequencing, and the dietary intake and anthropometric measurements were collected. Alpha diversity analysis revealed a lower Chao1 index of the bacterial genera in the IBD groups. Beta diversity analysis showed significant differences in the bacterial composition, suggesting inter-individual variability within the healthy and IBD groups. Additionally, the relative abundance of the bacterial genera varied across the four groups. Faecalibacterium was more abundant in the IBD groups; Prevotella was found exclusively in the Mexican groups, and Akkermansia was found only in the Spanish groups. Akkermansia was positively correlated with meat and protein intake, Prevotella with lean mass, and Bacteroides with calorie intake. These findings highlight the importance of considering geographic and nutritional factors in future research on the gut microbiome’s role in IBD pathogenesis.

La enfermedad renal crónica es una condición que afecta la capacidad de los riñones para filtrar la sangre y eliminar sustancias de desecho del cuerpo, por lo que su atención requiere una evaluación integral del estado de salud del paciente. Durante años, el ABCD de la evaluación nutricional —Antropometría, Bioquímica, Clínica y Dietética— ha sido una herramienta ampliamente utilizada por profesionales de la salud para comprender el estado nutricional de las personas con enfermedad renal y orientar su tratamiento, sin embargo, los avances científicos de los últimos años han revelado que existe otro actor importante que también puede influir en la evolución de esta enfermedad: la microbiota intestinal, es decir, el conjunto de microorganismos que viven naturalmente en nuestro intestino. Cuando esta comunidad de microorganismos se encuentra en equilibrio, puede contribuir a diversas funciones del organismo, como el metabolismo de nutrientes y la regulación del sistema inmunológico. No obstante, cuando su composición se altera —un fenómeno conocido como disbiosis— puede favorecer la producción de compuestos tóxicos que llegan a la sangre y pueden agravar el daño renal. En este contexto, comprender la relación entre la microbiota intestinal y la enfermedad renal crónica abre nuevas oportunidades para mejorar el cuidado de los pacientes. Quizá, además del tradicional ABCD de la evaluación nutricional, en el futuro también debamos considerar una nueva letra: la M de microbiota.