Most gut microbiome studies are focused on populations from developed nations. However, this overlooks the role played by host genetics, lifestyle, and diet, highlighting the need to evaluate under-represented populations. Thus, we performed the first gut microbiome study from a Paraguayan cohort via 16S rRNA sequencing and PICRUSt2 analysis. We evaluated fecal samples from 60 participants from Asunción, while considering categories such as body-mass-index (BMI), sex, age, diet, lifestyle, and clinical history. Firmicutes (76.0 ± 11.6%), Actinobacteriota (10.4 ± 7.9%) and Bacteroidota (9.4 ± 11.4%) were the most abundant phyla. Similarly, the most abundant genera were Blautia (14.1 ± 7.5%), Faecalibacterium (8.07 ± 6.8%), and Bacteroides (6.7 ± 6.8%). Likewise, the most abundant microbial pathways were predicted to be involved with sugar metabolism and fermentation. Interestingly, some categories significantly impacted the gut microbiome composition and function, such as BMI (Moryella, Bifidobacterium), sex (Faecalibacterium), and others. Additionally, dysbiotic indices differed from values previously reported as homeostatic. These observations highlight the need for further studies, considering microbial species and host genetics. Thus, this work expands the knowledge of the gut microbiome from the Collective South, while contrasts found herein reinforce the need for further research with human populations traditionally understudied.

Trichoderma, un género de hongos filamentosos es ampliamente utilizado en la agricultura debido a sus propiedades y usos diversos, destacando su habilidad para funcionar como un agente biocontrolador contra diversos fitopatógenos. El éxito de Trichoderma se basa en múltiples mecanismos de acción, que incluyen antibiosis, micoparasitismo, competencia por espacio y nutrientes, producción de enzimas y metabolitos secundarios con actividad antimicrobiana y la estimulación de la respuesta de defensa de las plantas ante los patógenos. Esta mini revisión se centra en los mecanismos de acción de Trichoderma como biocontrolador y sus potencialidades para el uso en la agricultura. Este género de hongos filamentosos con capacidad para inhibir el crecimiento de patógenos, estimular el crecimiento de las plantas y mejorar la calidad del suelo lo convierten en un recurso valioso para los agricultores. El conocimiento de estos mecanismos puede ayudar a mejorar aún más su uso en la agricultura y promover prácticas agrícolas sostenibles.

The use of plant-growth-promoting microbes in agriculture is expected to double over the next decade due to several advantages. For example, they have a positive impact on soil health, and product yields and can increase traditional fertilizer’s bioavailability, reducing their use. This is based on the diverse metabolic capabilities conferred by microbes which are required by plants for a healthy development. Their application can be based either on microbial isolates or communities. The former comprises a reductionist approach that maximizes microbial load and few metabolic traits. Inversely, the latter focuses on metabolic diversity. Since fertile soils have diverse microbial communities or microbiomes, methods that replicate this habitat at an industrial scale can unlock a new class of bioadditives for organic and traditional farming. Moreover, since microbes can reduce traditional fertilizer use, which is the main contributor to greenhouse gas (GHG) emissions from agriculture, these biotechnologies can help decarbonize this industry. Therefore, in view of the role of microbes in soil health and nutrient management, efforts in fundamental and translational research on this topic are further needed. Thus, this chapter will explore the use of microbial biotechnology in agriculture, with a focus on a case study of a microbiome-based bioadditive.

Lactic acid is a compound used industrially due to its properties. There are two methods for its production: chemical synthesis and microbial fermentation. In microbial fermentation, food industry waste can be used as a substrate, providing a route towards achieving a circular economy. Thus, this study evaluated different substrates for Lactobacillus plantarum growth, a lactic acid producer, such as molasses, whey, glucose, and saccharose, either alone or supplemented with additional nutrients. Bacterial growth parameters were assessed using OD₆₂₀ measurement. It was shown that whey supplemented with yeast extract supported the best growth, allowing a μ_max = 0.63 h⁻¹.

Summary: Anaerobic metabolism of dietary choline to trimethylamine (TMA) by the human gut microbiome is a disease-associated pathway. The host’s impaired ability to oxidize TMA to trimethylamine- N -oxide (TMAO) results in trimethylaminuria (TMAU), while elevated serum TMAO levels have been positively correlated with cardiometabolic disease. Small molecule inhibition of gut bacterial choline metabolism attenuates the development of disease in mice, highlighting the therapeutic potential of modulating this metabolism. Inhibitors previously developed to target this pathway are often designed to mimic choline, the substrate of the key TMA-generating enzyme choline trimethylamine-lyase (CutC). Here, we use a growth-based phenotypic high-throughput screen and medicinal chemistry to identify distinct chemical scaffolds that can modulate anaerobic microbial choline metabolism and lower TMAO levels in vivo . These results illustrate the potential of using phenotypic screening to rapidly discover new inhibitors of gut microbial metabolic activities.