Emerging Evidence on the Use of Probiotics and Prebiotics to Improve the Gut Microbiota of Older Adults with Frailty Syndrome: A Narrative Review.

BACKGROUND: The gut microbiota can impact older adults' health, especially in patients with frailty syndrome. Understanding the association between the gut microbiota and frailty syndrome will help to explain the etiology of age-related diseases. Low-grade systemic inflammation is a factor leading to geriatric disorders, which is known as "inflammaging". Intestinal dysbiosis has a direct relationship with low-grade systemic inflammation because when the natural gut barrier is altered by age or other factors, some microorganisms or their metabolites can cross this barrier and reach the systemic circulation. OBJECTIVES: This review had two general goals: first, to describe the characteristics of the gut microbiota associated with age-related diseases, specifically frailty syndrome. The second aim was to identify potential interventions to improve the composition and function of intestinal microbiota, consequently lessening the burden of patients with frailty syndrome. METHODS: A search of scientific evidence was performed in PubMed, Science Direct, and Redalyc using keywords such as "frailty", "elderly", "nutrient interventions", "probiotics", and "prebiotics". We included studies reporting the effects of nutrient supplementation on frailty syndrome and older adults. These studies were analyzed to identify novel therapeutic alternatives to improve gut microbiota characteristics as well as subclinical signs related to this condition. RESULTS: The gut microbiota participates in many metabolic processes that have an impact on the brain, muscles, and other organs. These processes integrate feedback mechanisms, comprising their respective axis with the intestine and the gut microbiota. Alterations in these associations can lead to frailty. We report a few interventions that demonstrate that prebiotics and probiotics could modulate the gut microbiota in humans. Furthermore, other nutritional interventions could be used in patients with frailty syndrome. CONCLUSION: Probiotics and prebiotics may potentially prevent frailty syndrome or improve the quality of life of patients with this disorder. However, there is not enough information about their appropriate doses and periods of administration. Therefore, further investigations are required to determine these factors and improve their efficacy as therapeutic approaches for frailty syndrome.

Complete Genome Sequence of Halomonas venusta Type Strain DSM 4743, a Moderately Halophilic Marine Bacterium.

Here, we report the genome sequence of Halomonas venusta strain DSM 4743T, a moderately halophilic marine bacterium. This type species genome consists of a 4.3-Mb chromosome, with 3,777 protein-coding genes, 60 tRNA loci, and 6 complete rRNA operons, plus a 6.1-kb plasmid termed p4743-A.

Simultaneous nitrification/denitrification and desulfurization of wastewater polluted with ammonium, COD and sulfide: effectiveness of a new up-flow vertical hybrid reactor.

Industrial wastewater discharges pose an environmental risk. Here, the effectiveness of an up-flow vertical hybrid system, operating with synthetic and industrial wastewater was investigated, as a new approach to perform nitrification/denitrification and desulfurization within a single reactor. The hybrid reactor is divided in two reaction zones, the oxic and anoxic. The removal of chemical oxygen demand (COD), ammonium, and sulfide was investigated, highlighting changes in microbial diversity. The reactor was evaluated at hydraulic residence time (HRT) of 1.6 days, and its performance throughout 180 days is presented in four stages. In stages I-II, high COD and ammonium removal was obtained with synthetic wastewater. In stage-III, sulfide-rich synthetic wastewater did not alter the system, attaining COD, ammonium, and sulfide removal efficiencies of 81, 99.5, and 99.7%, respectively. In the last stage, a mixture of effluents was fed into the reactor at loading rates of 277 mg COD/L-d, 46.5 mg NH4 +-N /L-d, and 15 mg HS--S /L-d. Sulfide and ammonium removals were 100% and 99.9%, respectively. However, low COD removal was observed, being of 51%, and the system removed 97% in terms of BOD5. The structure and microbial diversity also changed. Sulfide feeding, induced the proliferation of sulfur oxidizers like Thiomiscropira and Thiobacillus. Industrial wastewater enhanced the abundance of Pseudomonas (15.53%) and favored the proliferation of new bacteria of the genus Truepera (2.98%) and Alicyclipilus (7.56%). This is the first study reporting simultaneous nitrification/denitrification and desulfurization to remove ammonium, COD and sulfide from complex industrial wastewater using an up-flow vertical hybrid reactor.