Diurnal rhythmicity of infant fecal microbiota and metabolites: A randomized controlled interventional trial with infant formula

Improving fat globule structure to narrow metabolite gap between human milk and infant formulae

We hypothesized that improving the fat globule structure of infant formulae based on the milk fat globule membrane (MFGM) would regulate metabolites and metabolic pathways, making it more similar to the metabolic properties of human milk. Therefore, we prepared infant formulae with different fat globule structures, including two model infant formulae (F1: fat globules surrounded by MFGM; F2: fat globules surrounded by protein) and one commercial infant formulae containing MFGM, and compared their metabolic differences with those of human milk. The number of differential metabolites between each sample and human milk reached 60 (F1), 132 (F2) and 126 (IF1). Glycerophosphocholines were screened as potential biomarkers to distinguish infant formulae from human milk. Compared with F2 and IF1, the enrichment of amino acid metabolism and lipid metabolism pathways was not significant between F1 and human milk. These results emphasized that F1 had the highest similarity to human milk in metabolic properties.

The infant microbiota hopscotches between community states toward maturation-longitudinal stool parameters and microbiota development in a cohort of European toddlers

The development of the gut microbiome is critical during early life and is associated with infant health. To test whether this development is deterministic and how it is influenced by factors such as diet and mode of birth, we studied microbiota profiles and fecal parameters of 540 European infants, fed a synbiotic or control infant formula during their first year of life, up to 36 months of age. The diversity of the microbiota gradually increased until 36 months, at which point it resembled adult community states, indicating that microbiota maturation had occurred. However, distinct gut microbiota community states were observed that differed at each stage of maturation. The distribution of infants within the communities even at 36 months was significantly influenced by early life events, with a higher prevalence of infants born by cesarean section having the immature M36-C1 community state at 36 months. The microbial community state at one time point was not predictive of the next; instead, we observed hopscotching of the infant microbiota between different community states. This work provides new longitudinal data on the infant gut microbiome in relation to diet, suggesting that ecosystem development is not deterministic, but that early life events influence the community state of an individual's gut microbiota beyond infancy.

Protocol to study human gut bacterial communities and rhythmicity ex vivo using a chemostat system

Chemostat systems can be used to cultivate complex intestinal microbial communities ex vivo. Here, we present a protocol to transfer bacteria from human fecal material into chemostat systems as well as settings to simulate infant or adult colonic conditions. We describe the experimental setup, media design, donor selection, 16S rRNA amplicon sequencing, and circadian analysis of bacterial abundance. This protocol enables the investigation of changes in microbial community composition and bacteria-derived metabolites upon exposure to different dietary components. For complete details on the use and execution of this protocol, please refer to Heppner et al.1.

The effect of complementary foods on the colonic microbiota of weaning infants: a systematic review

The transition from breastmilk to solid foods (weaning) is a decisive stage for the development of the colonic microbiota. However, little is known about how complementary foods influence the composition and function of the colonic microbiota in infants. This systematic review collected evidence of the effect of individual foods on the fecal microbiota of weaning infants (4-12 months old) using five databases: PubMed, CENTRAL, Scopus, Web of Science, and ScienceDirect. A total of 3625 records were examined, and seven randomized clinical trials met the review's eligibility criteria. Altogether, 983 participants were enrolled, and plant-based foods, meats, and dairy products were used as interventions. Wholegrain cereal increased the fecal abundance of the order Bacteroidales in the two included studies. Pureed beef increased the fecal abundances of the genus Bacteroides and the Clostridium XIVa group, as well as microbial richness in two of the three included studies. However, the conclusions of this review are limited by the small number of studies included. No conclusions could be drawn about the impact of complementary foods on fecal metabolites. Further clinical trials assessing the effect of dietary interventions on both fecal microbial composition and function are needed to fill this knowledge gap in infant nutrition.

Exploring the Potential Probiotic Properties of Bifidobacterium breve DSM 32583-A Novel Strain Isolated from Human Milk

Human milk is the best nutrition for infants, providing optimal support for the developing immune system and gut microbiota. Hence, it has been used as source for probiotic strain isolation, including members of the genus Bifidobacterium, in an effort to provide beneficial effects to infants who cannot be exclusively breastfed. However, not all supplemented bifidobacteria can effectively colonise the infant gut, nor confer health benefits to the individual infant host; therefore, new isolates are needed to develop a range of dietary products for this specific age group. Here, we investigated the beneficial potential of Bifidobacterium breve DSM 32583 isolated from human milk. We show that in vitro B. breve DSM 32583 exhibited several characteristics considered fundamental for beneficial bacteria, including survival in conditions simulating those present in the digestive tract, adherence to human epithelial cell lines, and inhibition of growth of potentially pathogenic microorganisms. Its antibiotic resistance patterns were comparable to those of known beneficial bifidobacterial strains, and its genome did not contain plasmids nor virulence-associated genes. These results suggest that B. breve DSM 32583 is a potential probiotic candidate.

GOSpel for tiny allies

Infant formulas are often supplemented to foster the development of a healthy gut microbiota. In this issue of Cell Host & Microbe, Heppner et al. present an elaborate clinical trial examining the impact of formula supplementation on the development and circadian rhythmicity of the microbiota during the first year of life.