19 research outputs found
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We
estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from
1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods We used data from 3663 population-based studies with 222 million participants that measured height and
weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate
trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children
and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the
individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference)
and obesity (BMI >2 SD above the median).
Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in
11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed
changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and
140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of
underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and
countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior
probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse
was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of
thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a
posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%)
with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and
obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for
both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such
as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged
children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls
in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and
42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents,
the increases in double burden were driven by increases in obesity, and decreases in double burden by declining
underweight or thinness.
Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an
increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy
nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of
underweight while curbing and reversing the increase in obesit
Study at molecular and cellular level of mycosubtilin synthesis
Cette thèse a porté sur l’étude de la biosynthèse d’un lipopeptide antifongique, la mycosubtiline, produit par Bacillus subtilis ATCC6633 sous la forme d’un mélange d’isoformes qui varient selon la longueur et l’isomérie de leur chaine d’acide gras. La nature de l’acide gras influence l’activité biologique du lipopeptide. La corrélation entre la synthèse des isoformes de mycosubtiline et d’acides gras cellulaires a été étudiée en faisant varier des conditions de culture telles que l’osmolarité, la température et la source d’azote. Les variations du profil d’acides gras influencent dans la majorité des cas le profil des mycosubtilines obtenues confirmant le rôle important de ces précurseurs pour la synthèse du lipopeptide. Les effets de la modification génétique de deux gènes intervenant dans la synthèse de ces précurseurs ont été également caractérisés. La surexpression du gène ilvA codant pour la thréonine déshydratase et intervenant donc dans la synthèse de l’isoleucine augmente la synthèse de la mycosubtiline anteisoC17 alors que l’interruption d’un gène régulateur pléiotropique codY favorise la formation de la forme isoC16. Une souche monoproductrice constitutive de mycosubtiline, obtenue par optimisation génétique de la souche ATCC 6633 a également été caractérisée. Enfin, une première approche de purification des synthétases impliquées dans la synthèse de la mycosubtiline a été réalisée. Ces études ont contribuées à une meilleure compréhension des paramètres influençant « in vivo » cette synthèse, ainsi qu’à l’amélioration de la production de mycosubtiline, et à la définition des conditions optimales d’obtention des isoformes les plus actives.This thesis is about the study of an antifungal lipopeptide , the mycosubtilin produced by Bacillus subtilis ATCC 6633 as a co-production of isoforms which vary according to the length and the isomery of the fatty acids chain (mostly nC16, isoC16, nC17, isoC17 and anteisoC17). The nature of fatty acid chain influences the biological activity of the lipopeptide. The relationship between the mycosubtilin isoforms synthesis and the fatty acids synthesis was studied by the variation of growth parameters like osmolarity, temperature and nitrogen source. The important role of fatty acids precursors for the lipopeptides synthesis was confirmed by the influence of fatty acids pattern variations on the mycosubtilines pattern. The effects of genetic modification of two genes involved in synthesis of fatty acids precursors were also characterized. The overexpression of ilA coding for threonine deshydratase, involved in isoleucine synthesis increase the mycosubtilin anteisoC17 production while the knock-out of the pleitropic regulator gene codY improves the isoC16 mycosubtilin synthesis. Moreover, a mycosubtilin constitutive monoproductive strain, obtained by genetic optimization of ATCC 6633 strain was also characterized. Then, a preliminary purification approach of synthetases implied in mycosubtilin synthesis was realized. Those studies contribute to a better understanding of parameters influencing in vivo synthesis as well as the improvement of mycosubtilin production and the definition of optimal conditions to obtain the most active isoforms
Effect of low temperatures on growth and biosurfactant production in Bacillus subtilis
International audienc
Etude à l'échelle cellulaire et moléculaire de la synthèse de la mycosubtiline
Cette thèse a porté sur l étude de la biosynthèse d un lipopeptide antifongique, la mycosubtiline, produit par Bacillus subtilis ATCC6633 sous la forme d un mélange d isoformes qui varient selon la longueur et l isomérie de leur chaine d acide gras. La nature de l acide gras influence l activité biologique du lipopeptide. La corrélation entre la synthèse des isoformes de mycosubtiline et d acides gras cellulaires a été étudiée en faisant varier des conditions de culture telles que l osmolarité, la température et la source d azote. Les variations du profil d acides gras influencent dans la majorité des cas le profil des mycosubtilines obtenues confirmant le rôle important de ces précurseurs pour la synthèse du lipopeptide. Les effets de la modification génétique de deux gènes intervenant dans la synthèse de ces précurseurs ont été également caractérisés. La surexpression du gène ilvA codant pour la thréonine déshydratase et intervenant donc dans la synthèse de l isoleucine augmente la synthèse de la mycosubtiline anteisoC17 alors que l interruption d un gène régulateur pléiotropique codY favorise la formation de la forme isoC16. Une souche monoproductrice constitutive de mycosubtiline, obtenue par optimisation génétique de la souche ATCC 6633 a également été caractérisée. Enfin, une première approche de purification des synthétases impliquées dans la synthèse de la mycosubtiline a été réalisée. Ces études ont contribuées à une meilleure compréhension des paramètres influençant in vivo cette synthèse, ainsi qu à l amélioration de la production de mycosubtiline, et à la définition des conditions optimales d obtention des isoformes les plus actives.This thesis is about the study of an antifungal lipopeptide , the mycosubtilin produced by Bacillus subtilis ATCC 6633 as a co-production of isoforms which vary according to the length and the isomery of the fatty acids chain (mostly nC16, isoC16, nC17, isoC17 and anteisoC17). The nature of fatty acid chain influences the biological activity of the lipopeptide. The relationship between the mycosubtilin isoforms synthesis and the fatty acids synthesis was studied by the variation of growth parameters like osmolarity, temperature and nitrogen source. The important role of fatty acids precursors for the lipopeptides synthesis was confirmed by the influence of fatty acids pattern variations on the mycosubtilines pattern. The effects of genetic modification of two genes involved in synthesis of fatty acids precursors were also characterized. The overexpression of ilA coding for threonine deshydratase, involved in isoleucine synthesis increase the mycosubtilin anteisoC17 production while the knock-out of the pleitropic regulator gene codY improves the isoC16 mycosubtilin synthesis. Moreover, a mycosubtilin constitutive monoproductive strain, obtained by genetic optimization of ATCC 6633 strain was also characterized. Then, a preliminary purification approach of synthetases implied in mycosubtilin synthesis was realized. Those studies contribute to a better understanding of parameters influencing in vivo synthesis as well as the improvement of mycosubtilin production and the definition of optimal conditions to obtain the most active isoforms.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF
Semi-quantitative real-time PCR: A useful approach to identify persons with low replicative chronic hepatitis B
International audienceAntiviral therapy can be avoided during the low replicative phase of chronic Hepatitis B virus (HBV) infection which is characterized notably by HBV DNA concentration below 2000IU/ml. Simplified diagnostic tests can improve access to HBV DNA monitoring in resource-limited settings. The capacity of a new semi-quantitative real-time PCR approach based on sample-to-standard relative detection of the target to discriminate samples with HBV DNA levels above or below the clinical threshold of 2000IU/ml was compared to a quantitative assay (Roche CobasAmpliPrep/CobasTaqMan HBV Test v2.0). The semi-quantitative assay correctly identified 40/40 (100%) low replicative HBV DNA patients and 58/61 (95%) samples from HBV-infected subjects with moderate/high levels of viral DNA. Our results suggested that this alternative PCR test is efficient to guide therapeutic decision based on identification of low replicative HBV infection from all of the chronic hepatitis B carriers requiring treatment, and may be useful in resource-limited settings where the vast majority of cases live
Bioinformatics Modelling and Metabolic Engineering of the Branched Chain Amino Acid Pathway for Specific Production of Microbial Biosurfactants and Biopesticides
International audienceThe lipopeptides produced by B. subtilis have a wide range of activities. For example, mycosubtilin is a strong antifungal molecule and surfactin is one of the most powerful biosurfactants known. These two bioactive molecules can be used in many markets (cosmetics, phytosanitary, detergents, etc) and their industrial production is being developed in Europe and Asia. Both molecules are made up of a cyclic heptapeptide linked to a fatty acid chain. The isomery and the length of the fatty acid chain (FA) are responsible for the activities of the lipopeptides. In this work, the activities of the different lipopeptide isoforms were first investigated for their surfactant property or antifungal activities against several pathogens, revealing the strong surfactant activity of the surfactin isoform nC14 and the strong antifungal activity of the mycosubtilin isoform anteiso-C17. Then, the modification of lipopeptides production was studied by amino acid feeding experiments. In parallel, bioinformatic and metabolic engineering strategies were performed. The knockout (KO) or overexpression of genes, leading to the specific overproduction of the most active surfactin or mycosubtilin isoforms, were predicted using computational tools that provide logical reasoning with formal models of reaction networks. In this way, different genes impacting the production of amino acids or branched-chain fatty acids or the regulation of these metabolic pathways were identified and targeted for KO or overexpression. The influence of these deletions or these overexpressions on the quantitative and qualitative lipopeptides production was analysed using HPLC, LC-MS-MS and GC-MS methods. To better understand the impact of certain deletions on the metabolism of strains and the production of their lipopeptides, two different approaches were undertaken. On the one hand, for the production of surfactin, a complete analysis of extracellular metabolites by quantitative 1H NMR was used. On the other hand, for the production of mycosubtilin, a comprehensive analysis of cellular fatty acid production was undertaken using GC-MS. The results obtained show important metabolic changes in the different mutants allowing an increase in the specific production of the nC14 isoform from 1.4 to 5.8 times and of the mycosubtilin anteiso-C17 from 1.4 to 2.8 timesThese results show that increased selective synthesis of particular lipopeptide isoforms by metabolic engineering and bioinformatics-assisted synthetic biology is possible, revealing the interest of these approaches for the future development of lipopeptide-producing strains and for more targeted application
Bioinformatics Modelling and Metabolic Engineering of the Branched Chain Amino Acid Pathway for Specific Production of Microbial Biosurfactants and Biopesticides
International audienceThe lipopeptides produced by B. subtilis have a wide range of activities. For example, mycosubtilin is a strong antifungal molecule and surfactin is one of the most powerful biosurfactants known. These two bioactive molecules can be used in many markets (cosmetics, phytosanitary, detergents, etc) and their industrial production is being developed in Europe and Asia. Both molecules are made up of a cyclic heptapeptide linked to a fatty acid chain. The isomery and the length of the fatty acid chain (FA) are responsible for the activities of the lipopeptides. In this work, the activities of the different lipopeptide isoforms were first investigated for their surfactant property or antifungal activities against several pathogens, revealing the strong surfactant activity of the surfactin isoform nC14 and the strong antifungal activity of the mycosubtilin isoform anteiso-C17. Then, the modification of lipopeptides production was studied by amino acid feeding experiments. In parallel, bioinformatic and metabolic engineering strategies were performed. The knockout (KO) or overexpression of genes, leading to the specific overproduction of the most active surfactin or mycosubtilin isoforms, were predicted using computational tools that provide logical reasoning with formal models of reaction networks. In this way, different genes impacting the production of amino acids or branched-chain fatty acids or the regulation of these metabolic pathways were identified and targeted for KO or overexpression. The influence of these deletions or these overexpressions on the quantitative and qualitative lipopeptides production was analysed using HPLC, LC-MS-MS and GC-MS methods. To better understand the impact of certain deletions on the metabolism of strains and the production of their lipopeptides, two different approaches were undertaken. On the one hand, for the production of surfactin, a complete analysis of extracellular metabolites by quantitative 1H NMR was used. On the other hand, for the production of mycosubtilin, a comprehensive analysis of cellular fatty acid production was undertaken using GC-MS. The results obtained show important metabolic changes in the different mutants allowing an increase in the specific production of the nC14 isoform from 1.4 to 5.8 times and of the mycosubtilin anteiso-C17 from 1.4 to 2.8 timesThese results show that increased selective synthesis of particular lipopeptide isoforms by metabolic engineering and bioinformatics-assisted synthetic biology is possible, revealing the interest of these approaches for the future development of lipopeptide-producing strains and for more targeted application
Environmental factors and pleitropic regulators influence homologous compound pattern of mycosubtilin produced by Bacillus subtilis ATCC 6633.
International audienc