Local domestication of lactic acid bacteria via cassava beer fermentation

Cassava beer, or chicha, is typically consumed daily by the indigenous Shuar people of the Ecuadorian Amazon. This traditional beverage made from cassava tuber (Manihot esculenta) is thought to improve nutritional quality and flavor while extending shelf life in a tropical climate. Bacteria responsible for chicha fermentation could be a source of microbes for the human microbiome, but little is known regarding the microbiology of chicha. We investigated bacterial community composition of chicha batches using Illumina high-throughput sequencing. Fermented chicha samples were collected from seven Shuar households in two neighboring villages in the Morona-Santiago region of Ecuador, and the composition of the bacterial communities within each chicha sample was determined by sequencing a region of the 16S ribosomal gene. Members of the genus Lactobacillus dominated all samples. Significantly greater phylogenetic similarity was observed among chicha samples taken within a village than those from different villages. Community composition varied among chicha samples, even those separated by short geographic distances, suggesting that ecological and/or evolutionary processes, including human-mediated factors, may be responsible for creating locally distinct ferments. Our results add to evidence from other fermentation systems suggesting that traditional fermentation may be a form of domestication, providing endemic beneficial inocula for consumers, but additional research is needed to identify the mechanisms and extent of microbial dispersal

Market Integration and Soil-Transmitted Helminth Infection among the Shuar of Amazonian Ecuador

Background Soil-transmitted helminth (STH) infections have many negative health outcomes (e.g., diarrhea, nutritional deficiencies) that can also exacerbate poverty. These infections are generally highest among low-income populations, many of which are also undergoing market integration (MI; increased participation in a market-based economy). Yet the direct impact of MI-related social and environmental changes on STH infection patterns is poorly understood, making it unclear which lifestyle factors should be targeted to better control disease spread. This cross-sectional study examines if household infrastructure associated with greater MI is associated with lower STH burdens among Indigenous Ecuadorian Shuar. Methods Kato-Katz fecal smears were used to determine STH infection status and intensity (n = 620 participants; 308 females, 312 males, aged 6 months—86 years); Ascaris lumbricoides (ascarid) and Trichuris trichiura (whipworm) were the primary infection types detected. Structured interviews assessing lifestyle patterns (e.g., measures of household infrastructure) measured participant MI. Multilevel regression analyses and zero-inflated negative binomial regression models tested associations between MI measures and STH infection status or intensity, controlling for individual and community characteristics. Results Participants residing in more market-integrated households exhibited lower infection rates and intensities than those in less market integrated households. Parasite infection status and T. trichiura infection intensity were lower among participants living in houses with wood floors than those with dirt floors, while individuals using well or piped water from a spring exhibited lower A. lumbricoides infection intensities compared to those using river or stream water. Unexpectedly, latrine type was not significantly related to STH infection status or intensity. These results suggest that sources of exposure differ between the two helminth species. Conclusions This study documents associations between household measures and STH infection among an Indigenous population undergoing rapid MI. These findings can help healthcare programs better target interventions and reduce STH exposure among at-risk populations

Regional variation in Ascaris lumbricoides and Trichuris trichiura infections by age cohort and sex: effects of market integration among the indigenous Shuar of Amazonian Ecuador

Background: Soil-transmitted helminth (STH) infection peaks during childhood and varies by sex. The impact of market integration (MI) (increasing production for and consumption from a market-based economy) on these infection patterns, however, is unclear. In this study, STH infection is examined by sex and age among indigenous Shuar inhabiting two regions of Amazonian Ecuador: (1) the modestly market-integrated Upano Valley (UV) and (2) the more traditional Cross-Cutucú (CC) region. Methods: Kato-Katz fecal smears were examined for parasite presence and infection intensity. Factorial ANOVAs and post hoc simple effects analyses were performed by sex to compare infection intensity between regions and age categories (infant/child, juvenile/adolescent, adult). Results: Significant age and regional differences in Ascaris lumbricoides and Trichuris trichiura infection were detected. Overall, infants/children and juveniles/adolescents displayed higher parasite loads than adults. CC females exhibited higher A. lumbricoides loads than UV females, while the opposite pattern was observed for T. trichiura infection in males. Conclusions: Regional infection patterns varied by sex and parasite species, perhaps due to MI-linked environmental and lifestyle changes. These results have public health implications for the identification of individuals at risk for infection and contribute to ongoing efforts to track changes and alleviate STH infection in indigenous populations undergoing MI

Market Integration Predicts Human Gut Microbiome Attributes across a Gradient of Economic Development

Economic development is marked by dramatic increases in the incidence of microbiome-associated diseases, such as autoimmune diseases and metabolic syndromes, but the lifestyle changes that drive alterations in the human microbiome are not known. We measured market integration as a proxy for economically related lifestyle attributes, such as ownership of specific market goods that index degree of market integration and components of traditional and nontraditional (more modern) house structure and infrastructure, and profiled the fecal microbiomes of 213 participants from a contiguous, indigenous Ecuadorian population. Despite relatively modest differences in lifestyle across the population, greater economic development correlated with significantly lower within-host diversity, higher between-host dissimilarity, and a decrease in the relative abundance of the bacterium Prevotella. These microbiome shifts were most strongly associated with more modern housing, followed by reduced ownership of traditional subsistence lifestyle-associated items

Enantioselective, intermolecular benzylic C–H amination catalysed by an engineered iron-haem enzyme

C–H bonds are ubiquitous structural units of organic molecules. Although these bonds are generally considered to be chemically inert, the recent emergence of methods for C–H functionalization promises to transform the way synthetic chemistry is performed. The intermolecular amination of C–H bonds represents a particularly desirable and challenging transformation for which no efficient, highly selective, and renewable catalysts exist. Here we report the directed evolution of an iron-containing enzymatic catalyst—based on a cytochrome P450 monooxygenase—for the highly enantioselective intermolecular amination of benzylic C–H bonds. The biocatalyst is capable of up to 1,300 turnovers, exhibits excellent enantioselectivities, and provides access to valuable benzylic amines. Iron complexes are generally poor catalysts for C–H amination: in this catalyst, the enzyme's protein framework confers activity on an otherwise unreactive iron-haem cofactor

Global comparison of warring groups in 2002–2007: fatalities from targeting civilians vs. fighting battles

Background Warring groups that compete to dominate a civilian population confront contending behavioral options: target civilians or battle the enemy. We aimed to describe degrees to which combatant groups concentrated lethal behavior into intentionally targeting civilians as opposed to engaging in battle with opponents in contemporary armed conflict. Methodology/Principal Findings We identified all 226 formally organized state and non-state groups (i.e. actors) that engaged in lethal armed conflict during 2002–2007: 43 state and 183 non-state. We summed civilians killed by an actor's intentional targeting with civilians and combatants killed in battles in which the actor was involved for total fatalities associated with each actor, indicating overall scale of armed conflict. We used a Civilian Targeting Index (CTI), defined as the proportion of total fatalities caused by intentional targeting of civilians, to measure the concentration of lethal behavior into civilian targeting. We report actor-specific findings and four significant trends: 1.) 61% of all 226 actors (95% CI 55% to 67%) refrained from targeting civilians. 2.) Logistic regression showed actors were more likely to have targeted civilians if conflict duration was three or more years rather than one year. 3.) In the 88 actors that targeted civilians, multiple regressions showed an inverse correlation between CTI values and the total number of fatalities. Conflict duration of three or more years was associated with lower CTI values than conflict duration of one year. 4.) When conflict scale and duration were accounted for, state and non-state actors did not differ. We describe civilian targeting by actors in prolonged conflict. We discuss comparable patterns found in nature and interdisciplinary research. Conclusions/Significance Most warring groups in 2002–2007 did not target civilians. Warring groups that targeted civilians in small-scale, brief conflict concentrated more lethal behavior into targeting civilians, and less into battles, than groups in larger-scale, longer conflict

Physical activity and fat-free mass during growth and in later life

Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass.A study is presented of the association between FFM and physical activity in relation to age.In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3–96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution.PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76\% and 85\% of the variation in FFM in females and males < 18 y old, and 32\% and 47\% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants < 18 y old, mean FM-adjusted FFM was 1.7 kg (95\% CI: 0.1, 3.2 kg) and 3.4 kg (95\% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM–adjusted FFM was 3.6 kg (95\% CI: 2.8, 4.4 kg) and 4.4 kg (95\% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95\% CI: −0.2, 1.7 kg) and 1.0 kg (95\% CI: −0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively.If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults

Violent Deaths of Iraqi Civilians, 2003–2008: Analysis by Perpetrator, Weapon, Time, and Location

Madelyn Hsiao-Rei Hicks and colleagues provide a detailed analysis of Iraqi civilian violent deaths during 2003-2008 of the Iraq war and show that of 92,614 deaths, unknown perpetrators caused 74% of deaths, Coalition forces 12%, and Anti-Coalition forces 11%