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HIV infection results in marked alterations in the gut microbiota (GM), such as the loss of microbial diversity and different taxonomic and metabolic profiles. Despite antiretroviral therapy (ART) partially ablating gastrointestinal alterations, the taxonomic profile after successful new ART has shown wide variations. Our objective was to determine the GM composition and functions in people living with HIV (PLWHIV) under ART in comparison to seronegative controls (SC). Fecal samples from 21 subjects (treated with integrase strand-transfer inhibitors, INSTIs) and 18 SC were included. We employed 16S rRNA amplicon sequencing, coupled with PICRUSt2 and fecal short-chain fatty acid (SCFA) quantification by gas chromatography. The INSTI group showed a decreased α-diversity (p < 0.001) compared to the SC group, at the expense of increased amounts of Pseudomonadota (Proteobacteria), Segatella copri, Lactobacillus, and Gram-negative bacteria. Concurrently, we observed an enrichment in Megasphaera and Butyricicoccus, both SCFA-producing bacteria, and significant elevations in fecal butyrate in this group (p < 0.001). Interestingly, gut dysbiosis in PLWHIV was characterized by a proinflammatory environment orchestrated by Pseudomonadota and elevated levels of butyrate associated with bacterial metabolic pathways, as well as the evident presence of butyrogenic bacteria. The role of this unique GM in PLWHIV should be evaluated, as well as the use of butyrate-based supplements and ART regimens that contain succinate, such as tenofovir disoproxil succinate. This mixed profile is described for the first time in PLWHIV from Mexico. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of anaerobic fermentation on the in vitro ruminal production of total gas (TG), methane (CH4), carbon monoxide (CO) and hydrogen sulfide (H2S), as well as on the characteristics of ruminal fermentation and CH4 conversion efficiency of whole-plant maize (WPM) from four native maize genotypes (Amarillo, Olotillo, Tampiqueño and Tuxpeño) from Mexico, and a commercial hybrid was used as a control. In all genotypes, the fermented WPM produced the lowest amounts (p ≤ 0.0236) of TG and CH4 from degraded dry matter (DM), and Tampiqueño and Tuxpeño presented the highest production of these gases. In addition, Tuxpeño also presented the highest proportion of CH4 (mL 100 mL−1 TG), and Olotillo presented the lowest proportion of both gases. Something similar occurred in H2S, where the fermented WPM produced the lowest (p ≤ 0.0077) amount per DM degraded, and Amarillo and Tampiqueño presented the highest and lowest production, respectively. However, the fermented WPM presented the highest (p = 0.0128) CO production from degraded DM, and Tuxpeño and Olotillo presented the highest and lowest production, while the rumen pH was lower (p < 0.0001) in the fermented WPM, and Tuxpeño and Olotillo presented the highest and lowest pH, respectively. Furthermore, the fermented plant presented the greatest (p ≤ 0.0055) DM degradation, and the Amarillo and hybrid genotypes presented the highest percentages, while Olotillo presented the lowest. The short-chain fatty acid (SCFA) content and metabolizable energy (ME) did not differ (p ≥ 0.0899) between genotypes and were higher (p = 0.0009) in the fresh WPM. Despite the above, the fermented WPM was more efficient (p ≤ 0.0249), and the Amarillo and hybrid genotypes produced less CH4 per unit of SCFAs, ME and organic matter. In conclusion, the Amarillo genotype equaled the hybrid one, and although the production of CO increased, anaerobic fermentation showed the potential to reduce the rumen production of TG, CH4 and H2S, as well as to improve DM degradability and CH4 conversion efficiency. [ABSTRACT FROM AUTHOR]

Gut microbiota undergoes profound alterations in alcohol cirrhosis. Microbiota-derived products, e.g., short chain fatty acids (SCFA), regulate the homeostasis of the gut-liver axis. The objective was to evaluate the composition and functions of the intestinal microbiota in patients with alcohol-decompensated cirrhosis. Fecal samples of 18 patients and 18 healthy controls (HC) were obtained. Microbial composition was characterized by 16S rRNA amplicon sequencing, SCFA quantification was performed by gas chromatography (GC), and metagenomic predictive profiles were analyzed by PICRUSt2. Gut microbiota in the cirrhosis group revealed a significant increase in the pathogenic/pathobionts genera Escherichia/Shigella and Prevotella, a decrease in beneficial bacteria, such as Blautia, Faecalibacterium, and a decreased α-diversity (p < 0.001) compared to HC. Fecal SCFA concentrations were significantly reduced in the cirrhosis group (p < 0.001). PICRUSt2 analysis indicated a decrease in acetyl-CoA fermentation to butyrate, as well as an increase in pathways related to antibiotics resistance, and aromatic amino acid biosynthesis. These metabolic pathways have been poorly described in the progression of alcohol-related decompensated cirrhosis. The gut microbiota of these patients possesses a pathogenic/inflammatory environment; therefore, future strategies to balance intestinal dysbiosis should be implemented. These findings are described for the first time in the population of western Mexico. [ABSTRACT FROM AUTHOR]

Obesity and overweight are health problems of multifactorial etiology, which may include changes in the microbiome. In Mexico, more than 30 % of the child population between 5 and 11 years of age suffer from being overweight or are obese, which makes it a public health issue in progress. The purpose of this work was to measure the short-chain fatty acid concentration by high-performance liquid chromatography (HPLC), and to characterize the bacterial diversity by ion torrent semiconductor sequencing, of 16S rDNA libraries prepared from stools collected from a sample of well-characterized Mexican children for normal weight, overweight, and obese conditions by anthropometric and biochemical criteria. We found that triglyceride levels are increased in overweight and obese children, who presented altered propionic and butyric acid concentrations in feces. In addition, although the colon microbiota did not show a clear bacterial dysbiosis among the three conditions, the abundance of some particular bacteria was changed with respect to normal controls. We conclude from our results that the imbalance in the abundance of at least nine different bacteria as well as altered short-chain fatty acid concentration in feces is associated to the overweight and obese conditions of Mexican children. [ABSTRACT FROM AUTHOR]

• Bacteria diversity is dependent on the agave sap concentrate (ASC) production region. • ASC microbiota resists thermal and gastrointestinal conditions. • ASC microbiota has a high bacterial diversity with predominance of Firmicutes. • ASC microbiota produced short-chain fatty acids after in vitro fermentation. • ASC has potential as probiotic food product. Low bacterial diversity in the gut has been associated with the development of several diseases. Agave sap concentrate (ASC) is obtained from the thermal treatment of the fresh sap called "aguamiel", an artisanal Mexican food. In this study, we assessed the microbial diversity from three different ASC producing regions in Mexico using high-throughput sequencing of the 16S rRNA gene and evaluated their resistance to an in vitro gastrointestinal process as well as their ability to produce short-chain fatty acids (SCFA). Seven phyla and 120 genera were detected in ASC samples; Firmicutes had the highest relative read abundance at the phylum level, whereas Bacillus was the most abundant genus. Bacterial diversity at phylum and genus levels was highly dependent on the region where ASC was produced. The microbiota from a selected sample was resistant to low pH conditions, bile salts and intestinal enzymes. Moreover, bacteria were able to survive and grow in the colonic environment. SCFA production was comparable with that observed for a well-known probiotic, Lactobacillus plantarum 299v, that was used as control. These findings demonstrate that ASC contains a bacterial ecosystem with potential probiotic benefits. [ABSTRACT FROM AUTHOR]