Maternal IgA2 Recognizes Similar Fractions of Colostrum and Fecal Neonatal Microbiota

Microbiota acquired during labor and through the first days of life contributes to the newborn’s immune maturation and development. Mother provides probiotics and prebiotics factors through colostrum and maternal milk to shape the first neonatal microbiota. Previous works have reported that immunoglobulin A (IgA) secreted in colostrum is coating a fraction of maternal microbiota. Thus, to better characterize this IgA-microbiota association, we used flow cytometry coupled with 16S rRNA gene sequencing (IgA-Seq) in human colostrum and neonatal feces. We identified IgA bound bacteria (IgA+) and characterized their diversity and composition shared in colostrum fractions and neonatal fecal bacteria. We found that IgA2 is mainly associated with Bifidobacterium, Pseudomonas, Lactobacillus, and Paracoccus, among other genera shared in colostrum and neonatal fecal samples. We found that metabolic pathways related to epithelial adhesion and carbohydrate consumption are enriched within the IgA2+ fecal microbiota. The association of IgA2 with specific bacteria could be explained because these antibodies recognize common antigens expressed on the surface of these bacterial genera. Our data suggest a preferential targeting of commensal bacteria by IgA2, revealing a possible function of maternal IgA2 in the shaping of the fecal microbial composition in the neonate during the first days of life.

Effect of Solanum gilo leaf extract on some haematological indices of albino Wistar rats

Solanum gilo (eggplant) is an edible vegetable whose leaf is reported to possess numerous medicinal properties due to its rich constituents. Against this backdrop, there is possibility that its consumption may have effect on haematological indices. Therefore this research sought to assess the effect of Solanum gilo leaf diet on some haemotological indices of albino wistar rats. About twenty four (24) albino wistar rats weighing between 120-150mg were randomly assigned into four groups of six animals each. Each rat was allowed to drinking water ad labitum. Control group received normal rodent chow while group 2 was fed 5% Solanum gilo diet. Group 3 was fed 10% Solanum gilo diet and group 4 received 20% Solanum gilo diet. The different diets were prepared by mixing different proportions of ground S. gilo leaves with rodent chow. Automated blood cell analyzer (Model PCE 210, Japan) was used for analysis of haematological parameters. Preliminary study on its proximate composition, showed the appreciable presence of crude fat, protein, fibre and carbohydrate. Consumption of S. gilo caused significant improvement in some blood parameters; notably packed cell volume (PCV), white blood cell (WBC) and platelet counts. Hence, eggplant is a nutritious vegetable with healing, the therapeutic and immunity properties. If exploited in human diet has the potentials of improving quality of life.

Comparative Genomic Analysis of Novel Bifidobacterium longum subsp. longum Strains Reveals Functional Divergence in the Human Gut Microbiota

Bifidobacterium longum subsp. longum is a prevalent group in the human gut microbiome. Its persistence in the intestinal microbial community suggests a close host-microbe relationship according to age. The subspecies adaptations are related to metabolic capabilities and genomic and functional diversity. In this study, 154 genomes from public databases and four new Chilean isolates were genomically compared through an in silico approach to identify genomic divergence in genes associated with carbohydrate consumption and their possible adaptations to different human intestinal niches. The pangenome of the subspecies was open, which correlates with its remarkable ability to colonize several niches. The new genomes homogenously clustered within subspecies longum, as observed in phylogenetic analysis. B. longum SC664 was different at the sequence level but not in its functions. COG analysis revealed that carbohydrate use is variable among longum subspecies. Glycosyl hydrolases participating in human milk oligosaccharide use were found in certain infant and adult genomes. Predictive genomic analysis revealed that B. longum M12 contained an HMO cluster associated with the use of fucosylated HMOs but only endowed with a GH95, being able to grow in 2-fucosyllactose as the sole carbon source. This study identifies novel genomes with distinct adaptations to HMOs and highlights the plasticity of B. longum subsp. longum to colonize the human gut microbiota.

Positive interactions between lactic acid bacteria promoted by nitrogen-based nutritional dependencies

Nutritional dependencies, especially those regarding nitrogen sources, govern numerous microbial positive interactions. As for lactic acid bacteria (LAB), responsible for the sanitary, organoleptic, and health properties of most fermented products, such positive interactions have previously been studied between yogurt bacteria. However, they have never been exploited to create artificial co-cultures of LAB that would not necessarily coexist naturally, i.e from different origins. The objective of this study was to promote LAB positive interactions, based on nitrogen dependencies in co-cultures, and to investigate how these interactions affect some functional outputs, e.g. acidification rates, carbohydrate consumption, and volatile compound production. The strategy was to exploit both proteolytic activities and amino acid auxotrophies of LAB. A chemically defined medium was thus developed to specifically allow the growth of six strains used, three proteolytic and three non-proteolytic. Each of the proteolytic strains, Enterococcus faecalis CIRM-BIA2412, Lactococcus lactis NCDO2125, and CIRM-BIA244, was co-cultured with each one of the non-proteolytic LAB strains: L. lactis NCDO2111, Lactiplantibacillus plantarum CIRM-BIA465 and CIRM-BIA1524. Bacterial growth was monitored using compartmented chambers to compare growth in mono- and co-cultures. Acidification, carbohydrate consumption and volatile compound production was evaluated in direct co-cultures. Each proteolytic strain induced different types of interactions: either strongly positive, weakly positive, or no interactions, with E. faecalis CIRM-BIA2412, L. lactis NCDO2125 and L. lactis CIRM-BIA244, respectively. Strong interactions were associated with higher concentrations in tryptophan, valine, phenylalanine, leucine, isoleucine, and peptides. They led to faster acidification rates, lower pH, higher raffinose utilization and concentrations in five volatile compounds. Importance: Lactic acid bacteria (LAB) interactions are often studied in association with yeasts or propionibacteria in various fermented food products and the mechanisms underlying their interactions are being quite well characterized. Concerning interactions between LAB, they have mainly been investigated to test antagonistic interactions. Understanding how they can positively interact could be useful in multiple food-related fields: production of fermented food products with enhanced functional properties or fermentation of new food matrices. This study investigates the exploitation of the proteolytic activity of LAB strains to promote positive interactions between proteolytic and non-proteolytic strains. The results suggest that proteolytic LAB do not equally stimulate non-proteolytic LAB and that the stronger the interactions between LAB are, the more functional outputs we can expect. Thus, this study gives insight into how to create new associations of LAB strains and to guaranty their positive interactions.

Increased carbohydrate availability effects energy and nutrient periodisation of professional male athletes from the Australian Football League

This research aims to explore the effect of increased carbohydrate availability intervention on energy intake and distribution in professional Australian Football athletes. Six 24-h energy and macronutrient intakes were quantified (n= 19 males; age 24 ±4 y, stature 187 ±8 cm, mass 87 ±9 kg) using photographic food diaries and Foodworks analyses. Energy expenditure was estimated for the same period using GeneActiv accelerometers. During three control days, athletes had ad libitum access to food, while the three intervention days increased carbohydrate availability, through greater prompting and access to carbohydrate foods. Daily energy intake was higher during intervention (185 ±40 kJ/kg/d) compared with control (172 ±31 kJ/kg/d; p<0.05) but remained below estimated expenditure, and carbohydrate intake was also greater with intervention (5.0 ±0.2 g/kg/d) than control (4.0 ±0.2 g/kg/d; p<0.05). Expenditure was highest during the morning which coincided with lowest intake on all days, while the intervention was associated with greater carbohydrate intake in the morning (0.6 g/kg, p< 0.05) compared with control. Increasing availability of carbohydrate during high-load training generated a modest increase in carbohydrate and energy intake, and the intervention was most effective in improving carbohydrate intake during mornings. Novelty Bullets • Increased access and provision of carbohydrate foods increased carbohydrate consumption and energy intake on high training load days. • Daily distribution of energy intake can be modified through actively promoting carbohydrate consumption.

Sulfur Regulates the Trade-Off Between Growth and Andrographolide Accumulation via Nitrogen Metabolism in Andrographis paniculata

Nitrogen (N) and sulfur (S) are essential mineral nutrients for plant growth and metabolism. Here, we investigated their interaction in plant growth and andrographolide accumulation in medicinal plant Andrographis paniculata grown at different N (4 and 8 mmol·L−1) and S concentration levels (0.1 and 2.4 mmol L−1). We found that increasing the S application rate enhanced the accumulation of andrographolide compounds (AGCs) in A. paniculata. Simultaneously, salicylic acid (SA) and gibberellic acid 4 (GA4) concentrations were increased but trehalose/trehalose 6-phosphate (Tre/Tre6P) concentrations were decreased by high S, suggesting that they were involved in the S-mediated accumulation of AGCs. However, S affected plant growth differentially at different N levels. Metabolite analysis revealed that high S induced increases in the tricarboxylic acid (TCA) cycle and photorespiration under low N conditions, which promoted N assimilation and S metabolism, and simultaneously increased carbohydrate consumption and inhibited plant growth. In contrast, high S reduced N and S concentrations in plants and promoted plant growth under high N conditions. Taken together, the results indicated that increasing the S application rate is an effective strategy to improve AGC accumulation in A. paniculata. Nevertheless, the interaction of N and S affected the trade-off between plant growth and AGC accumulation, in which N metabolism plays a key role.

Variations in Microbial Diversity and Metabolite Profiles of Female Landrace Finishing Pigs With Distinct Feed Efficiency

To enhance pig production, feed efficiency (FE) should be improved; however, the mechanisms by which gut microbes affect FE in pigs have not been fully elucidated. To investigate the differences between the composition and functionality of the gut microbiota associated with low and high FE, microbial compositions were characterized using 16S rRNA sequencing, functional annotations were performed by shotgun metagenomics, and metabolomic profiles were created by GC-TOF-MS from female Landrace finishing pigs with low and high feed conversion ratios (FCRs). Lactobacillus was enriched in the gut microbiota of individuals with low FCRs (and thus high FE), while Prevotella abundance was significantly higher in individuals with high FCRs (and thus low FE). This may be linked to carbohydrate consumption and incomplete digestion. The activity of pathways involved in the metabolism of cofactors and vitamins was greater in pigs with lower FE. We also identified differences in pyruvate-related metabolism, including phenylalanine and lysine metabolism. This suggests that pyruvate metabolism is closely related to microbial fermentation in the colon, which in turn affects glycolysis. This study deepens our understanding of how gut microbiota are related to pig growth traits, and how regulating microbial composition could aid in improving porcine FE. However, these results need to be validated using a larger pig cohort in the future.

Dietary Intake and Daily Distribution of Carbohydrate, Protein and Fat in Youth Tennis Players over a 7-Day Training and Competition Period

During a 7-day training and/or competition period, macronutrient intake and distribution was assessed using food diaries, supported by remote food photography and 24-hr multiple pass recalls of youth tennis players categorised by under 12s, under 14s and under 16+ age groups (n = 27). Total energy did not differ between age groups nor type of day (training [TD], competition day [CD]), irrespective of a significant increase in body mass reported in the older players (U16+; p < 0.05). Average intakes were consistently below 2250 kcal·day-1 (range 1965 ± 317–2232 ± 612 kcal·day-1). Carbohydrate consumption was below guidelines for all groups (≤6g·kg-1). Conversely, protein intake met or exceeded guidelines throughout, with intakes ≥2 g·kg-1 for both the U12 and U14 age groups on both days. Protein intake was ~17% higher on TDs than CDs (p < 0.05), with protein intake at lunch significantly higher on TDs than CDs (p < 0.05). No further differences were observed between breakfast, lunch or dinner between group or day. Inconsistent snacking was reported, with players consuming snacks on less than half of the days reported (46 ± 12% of TDs and 43 ± 30% of CDs). In conclusion, youth tennis players present sub-optimal nutrition practices, appearing to under fuel and under consume carbohydrate for performance, adaptation, recovery and health.

Maternal IgA2 Association with Colostrum Microbiota Contributes to Bacteria Establishment During Intestinal Colonization in the Neonate.

Background: Microbiota colonization during labor and through the first meals contributes to immune maturation and development of the newborn. Mother provides probiotics and prebiotics factors through colostrum and maternal milk to shape the first neonatal microbiota. Previous works have reported that immunoglobulin A (IgA) secreted in colostrum is coating a fraction of maternal microbiota. Methods: Thus, to better characterize the IgA-associated microbiota, we used flow cytometry coupled with 16S rDNA gene sequencing (IgA-Seq) in human colostrum and neonatal feces. We identified IgA-bound bacteria (IgA+) and characterized its diversity to elucidate possible role of IgA subclasses during neonatal bacterial colonization of the colon.Results: We found that IgA2 in the colostrum has an active role during microbiota colonization. Colostrum IgA2 is mainly associated with Bifidobacterium, Lactobacillus, and Bacteroidetes genera. This association seems to give these bacteria an advantage during their establishment since metabolic pathways related to epithelial adhesion and carbohydrate consumption are enriched within fecal IgA2+ microbiota. Association with specific bacteria could be explained since IgA2 recognizes common antigens expressed on surfaces among bacteria genera.Conclusions: Our data suggest a specific targeting of commensal bacteria by IgA2 revealing a specialized function of IgA microbiota association during neonatal intestinal colonization during the first days of life.

The Impact of Fluid Loss and Carbohydrate Consumption during Exercise, on Young Cyclists’ Fatigue Perception in Relation to Training Load Level

High-level young athletes need to face a wide spectrum of stressors on their journey to élite categories. The aims of the present study are (i) to evaluate session rate of perceived exertion (sRPE) at different training impulse (TRIMP) categories and the correlations between these two variables and, (ii) evaluate the correlations between sRPE, fluid loss, and carbohydrate consumption during exercise. Data on Edward’s TRIMP, sRPE, body mass loss pre- and post- exercise (∆), and carbohydrate consumption (CHO/h) during exercise have been acquired from eight male junior cyclists during a competitive season. One-way ANOVA and correlation analysis with linear regression have been performed on acquired data. sRPE resulted in a significant difference in the three TRIMP categories (p < 0.001). sRPE resulted in being very largely positively associated with TRIMP values (p < 0.001; R = 0.71). ∆ as well as CHO/h was largely negatively related with sRPE in all TRIMP categories (p < 0.001). The results confirmed the role of fluid balance and carbohydrate consumption on the perception of fatigue and fatigue accumulation dynamics independently from the training load. Young athletes’ training load monitoring and nutritional-hydration support represent important aspects in athlete’s exercise-induced fatigue management.