Microbiota, Environment, and Diet

Abstract

Apropos: ''Gut Microbiota Differences in Children From Distinct Socioeconomic Levels Living in the Same Urban Area in Brazil''T o the Editor: The study authored by Mello et al (1) introduces a novel insight by comparing the human gut microbial composition in children living in the same geographic area, stratified by socioeconomic status. The authors, however, make conclusions that are not supported by the author's study results or methods. The authors failed to properly explain how the community leaders and researchers defined the classification requirements for a ''slum'' within the study area. Mello et al discussed the location of the perceived ''slum'' and presented example pictures of the area; however, detailed criteria to what constituted as a ''slum'' are missing and lead readers to believe slums were identified subjectively. A subjective approach to identifying ''slums'' will lead to selection bias drastically skewing the study results.In addition, the authors do not discuss the study's significant limitations, including the lack of a food diary collection, a crucial measure for establishing a baseline dietary picture for each study participant. Even though the authors discussed the differential dietary categories among the groups, it is curious that the authors decided not to do any kind of dietary data collection/analysis for this study group.Finally, it is crucial, even in studies not evaluating microbiota composition dynamics over time, to collect multiple samples to effectively judge the accuracy and consistency of the sample collection process. These practices will reduce error and increase confidence in eventual study conclusions.Future human gut microbiota-related studies must take greater care and deference in sound study design to avoid these problems in the future.

Effects of Earthworms on the Microbiomes and Antibiotic Resistomes of Detritus Fauna and Phyllospheres

“…Diet and soil properties are known to have a strong effect on the composition of the bacterial communities. 16 For example, different diets changes in food quality can alter the composition of termite 44,45 and collembolan microbiomes, 29,46 respectively, and different soil properties have been shown to cause a shift in collembolan, nematode, and enchytraeidassociated microbial communities. 15,32,34,47 In our study, the SEM also indicates that earthworms strongly affected soil properties, and soil properties make an important contribution to changes in microbial communities.…”

“…Earthworms are an essential component of soil ecosystems and are known as major ecosystem engineers, driving multiple soil ecological processes. − Through nonspecific feeding behaviors, intensive burrowing activity, and excretion and absorption, earthworms can impact the soil structure, gas diffusivity, resource allocation, and moisture and nutrient dynamics. − Two recent studies have confirmed that earthworms can significantly change the composition and structure of soil microbial communities. , Previous studies have indicated that earthworms can strongly affect the number and composition of other soil fauna in the soil and rhizosphere (e.g., earthworm impacts on nematodes, , collembolans, and enchytraeid worms) and the growth of plants, , either directly or by altering soil properties. It is well established that the environment makes an important contribution to animal and phyllosphere microbiomes. − However, effects of earthworms on the microbiomes of other soil fauna and phyllosphere are practically unknown.…”

Heat stress-induced mucosal barrier dysfunction is potentially associated with gut microbiota dysbiosis in pigs

“…Gut microbiota and its metabolites (short-chain fatty acids, SCFA) have attracted extensive attention for their usefulness in regulating immune system development and function, strengthening the gut barrier, metabolizing undigested nutrients and xenobiotics, mitigating oxidative stress, and eliminating pathogens ( Rooks and Garrett, 2016 ; Macpherson et al., 2017 ). Many factors contribute to the regulation of the intestinal microbiota composition, including diet ( Kolodziejczyk et al., 2019 ), host genetics ( Woo and Alenghat, 2017 ), and environment ( de Morais et al., 2017 ), but also stress ( Mackos et al., 2017 ). Accumulating evidence linking HS to intestinal damage suggest that the gut microbiota could be an underappreciated mediator of HS responses and associated sequelae in animals ( He et al., 2019 ; Xiong et al., 2020 ).…”