Suboptimal Refeeding Compensates Stunting in a Mouse Model of Juvenile Malnutrition.

Background: Early postnatal life is a critical period of rapid growth in mammals, heavily reliant on adequate nutrition. Protein-energy malnutrition (PEM) during this window can lead to stunting and wasting, with lasting health consequences.

Objectives: This study developed a mouse model of juvenile PEM to assess the effects of refeeding with various diets and interventions on growth recovery, including probiotic supplementation and suboptimal refeeding diets.

Protein restriction associated with high fat induces metabolic dysregulation without obesity in juvenile mice.

Dysregulation of energy metabolism, including hyperglycemia, insulin resistance and fatty liver have been reported in a substantial proportion of lean children. However, non-obese murine models recapitulating these features are lacking to study the mechanisms underlying the development of metabolic dysregulations in lean children. Here, we develop a model of diet-induced metabolic dysfunction without obesity in juvenile mice by feeding male and female mice a diet reflecting Western nutritional intake combined with protein restriction (mWD) during 5 weeks after weaning.

Intestinal GCN2 controls systemic growth in response to symbiotic cues encoded by r/tRNA operons.

Symbiotic bacteria interact with their host through symbiotic cues. Here, we took advantage of the mutualism between and (Lp) to investigate a novel mechanism of host-symbiont interaction. Using chemically defined diets, we found that association with Lp improves the growth of larvae-fed amino acid-imbalanced diets, even though Lp cannot produce the limiting amino acid.

Structure-function analysis of DltE reveals D-alanylated lipoteichoic acids as direct cues supporting juvenile growth.

Metazoans establish mutually beneficial interactions with their resident microorganisms. However, our understanding of the microbial cues contributing to host physiology remains elusive. Previously, we identified a bacterial machinery encoded by the operon involved in 's juvenile growth promotion by .

Microbe-mediated intestinal NOD2 stimulation improves linear growth of undernourished infant mice.

The intestinal microbiota is known to influence postnatal growth. We previously found that a strain of (strain Lp) buffers the adverse effects of chronic undernutrition on the growth of juvenile germ-free mice. Here, we report that Lp sustains the postnatal growth of malnourished conventional animals and supports both insulin-like growth factor-1 (IGF-1) and insulin production and activity.

Approaches to discern if microbiome associations reflect causation in metabolic and immune disorders.

Our understanding of microorganisms residing within our gut and their roles in the host metabolism and immunity advanced greatly over the past 20 years. Currently, microbiome studies are shifting from association and correlation studies to studies demonstrating causality of identified microbiome signatures and identification of molecular mechanisms underlying these interactions. This transformation is crucial for the efficient translation into clinical application and development of targeted strategies to beneficially modulate the intestinal microbiota.

DltC acts as an interaction hub for AcpS, DltA and DltB in the teichoic acid D-alanylation pathway of Lactiplantibacillus plantarum.

Teichoic acids (TA) are crucial for the homeostasis of the bacterial cell wall as well as their developmental behavior and interplay with the environment. TA can be decorated by different modifications, modulating thus their biochemical properties. One major modification consists in the esterification of TA by D-alanine, a process known as D-alanylation.

A standardized gnotobiotic mouse model harboring a minimal 15-member mouse gut microbiota recapitulates SOPF/SPF phenotypes.

Mus musculus is the classic mammalian model for biomedical research. Despite global efforts to standardize breeding and experimental procedures, the undefined composition and interindividual diversity of the microbiota of laboratory mice remains a limitation. In an attempt to standardize the gut microbiome in preclinical mouse studies, here we report the development of a simplified mouse microbiota composed of 15 strains from 7 of the 20 most prevalent bacterial families representative of the fecal microbiota of C57BL/6J Specific (and Opportunistic) Pathogen-Free (SPF/SOPF) animals and the derivation of a standardized gnotobiotic mouse model called GM15.

Microbial and nutritional influence on endocrine control of growth.

The worrying number of children suffering from undernutrition and consequent stunting worldwide makes the understanding of the relationship between nutritional status and postnatal growth crucial. Moreover, it is now well established that undernourished children harbor an altered microbiota, correlating with impaired growth. In this review, we describe how murine models have been used to explore the functional relationships between endocrine regulation of growth, nutrition and gut microbiota.

Effect of gut microbiota on depressive-like behaviors in mice is mediated by the endocannabinoid system.

Depression is the leading cause of disability worldwide. Recent observations have revealed an association between mood disorders and alterations of the intestinal microbiota. Here, using unpredictable chronic mild stress (UCMS) as a mouse model of depression, we show that UCMS mice display phenotypic alterations, which could be transferred from UCMS donors to naïve recipient mice by fecal microbiota transplantation.

Microbial Modulation of the Development and Physiology of the Enteric Nervous System.

The gastrointestinal tract harbors an intrinsic neuronal network, the enteric nervous system (ENS). The ENS controls motility, fluid homeostasis, and blood flow, but also interacts with other components of the intestine such as epithelial and immune cells. Recent studies indicate that gut microbiota diversification, which occurs alongside postnatal ENS maturation, could be critical for the development and function of the ENS.

WJL administration during pregnancy and lactation improves lipid profile, insulin sensitivity and gut microbiota diversity in dyslipidemic dams and protects male offspring against cardiovascular dysfunction in later life.

Background And Aim: Maternal dyslipidemia is recognized as a risk factor for the development of arterial hypertension (AH) and cardiovascular dysfunction in offspring. Here we evaluated the effects of probiotic administration of a specific strain of Lactiplantibacillus plantarum (WJL) during pregnancy and lactation on gut microbiota and metabolic profile in dams fed with a high-fat and high-cholesterol (HFHC) diet and its long-term effects on the cardiovascular function in male rat offspring.

Methods And Results: Pregnant Wistar rats were allocated into three groups: dams fed a control diet (CTL = 5), dams fed a HFHC diet (DLP = 5) and dams fed a HFHC diet and receiving L.

Draft Genome Sequences of 15 Bacterial Species Constituting the Stable Defined Intestinal Microbiota of the GM15 Gnotobiotic Mouse Model.

The GM15 community is a bacterial consortium used to generate a novel standardized mouse model with a simplified controlled intestinal microbiota recapitulating the specific opportunistic pathogen-free (SOPF) mouse phenotype and the potential to ensure an increased reproducibility and robustness of preclinical studies by limiting the confounding effect of microbiota composition fluctuation.

How commensal microbes shape the physiology of Drosophila melanogaster.

The interactions between animals and their commensal microbes profoundly influence the host's physiology. In the last decade, Drosophila melanogaster has been extensively used as a model to study host-commensal microbes interactions. Here, we review the most recent advances in this field.

Metabolic Cooperation among Commensal Bacteria Supports Drosophila Juvenile Growth under Nutritional Stress.

The gut microbiota shapes animal growth trajectory in stressful nutritional environments, but the molecular mechanisms behind such physiological benefits remain poorly understood. The gut microbiota is mostly composed of bacteria, which construct metabolic networks among themselves and with the host. Until now, how the metabolic activities of the microbiota contribute to host juvenile growth remains unknown.

An intestinal zinc sensor regulates food intake and developmental growth.

In cells, organs and whole organisms, nutrient sensing is key to maintaining homeostasis and adapting to a fluctuating environment. In many animals, nutrient sensors are found within the enteroendocrine cells of the digestive system; however, less is known about nutrient sensing in their cellular siblings, the absorptive enterocytes. Here we use a genetic screen in Drosophila melanogaster to identify Hodor, an ionotropic receptor in enterocytes that sustains larval development, particularly in nutrient-scarce conditions.

Drosophila-associated bacteria differentially shape the nutritional requirements of their host during juvenile growth.

The interplay between nutrition and the microbial communities colonizing the gastrointestinal tract (i.e., gut microbiota) determines juvenile growth trajectory.

Probiotic from human breast milk, Lactobacillus fermentum, promotes growth in animal model of chronic malnutrition.

Background: Chronic undernutrition leads to growth hormone resistance and poor growth in children, which has been shown to be modulated by microbiota. We studied whether Lactobacillus fermentum CECT5716 (Lf ), isolated from mother's breast milk, could promote juvenile growth through the modulation of lipid absorption in a model of starvation.

Methods: Germ-free (GF) Drosophila melanogaster larvae were inoculated with Lf in conditions of undernutrition with and without infant formula.

Qualification of tropical fruit-derived Lactobacillus plantarum strains as potential probiotics acting on blood glucose and total cholesterol levels in Wistar rats.

Tropical fruit and their industrial processing byproducts have been considered sources of probiotic Lactobacillus. Sixteen tropical fruit-derived Lactobacillus strains were assessed for growth-promoting effects using a host-commensal nutrient scarcity model with Drosophila melanogaster (Dm). Two Lactobacillus strains (L.

Commensal Gut Bacteria Buffer the Impact of Host Genetic Variants on Drosophila Developmental Traits under Nutritional Stress.

Eukaryotic genomes encode several buffering mechanisms that robustly maintain invariant phenotypic outcome despite fluctuating environmental conditions. Here we show that the Drosophila gut-associated commensals, represented by a single facultative symbiont, Lactobacillus plantarum (Lp), constitutes a so far unexpected buffer that masks the contribution of the host's cryptic genetic variation (CGV) to developmental traits while the host is under nutritional stress. During chronic under-nutrition, Lp consistently reduces variation in different host phenotypic traits and ensures robust organ patterning during development; Lp also decreases genotype-dependent expression variation, particularly for development-associated genes.

A New Transkingdom Dimension to NO Signaling.

Bacterial-derived metabolites profoundly influence the host's cellular and organismal physiology. Seth et al. (2019) report that via interspecies S-nitrosylation, microbiota-derived nitric oxide directly alters the host's Argonaute family protein activity, and consequently impinges on the overall post-transcriptional gene silencing program through the microRNA (miRNA) machinery.

Everyone wins.

bacteria living in the gut of zebrafish produce a specific molecule to pacify the immune system of their host.

Development of a PCR-RFLP assay to identify among field-collected larvae.

The fruit fly is a model organism to study several aspects of metazoan biology. Most of the work has been conducted in adult fruit flies, including laboratory and field-derived specimens, but larvae recently became a valuable model to better understand animal physiology, development, or host-microbe interactions. While adult flies can be easily assigned to a given species based on morphological characteristics, such visual identification is more intricate at the larval stage.